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Sample records for stringent rasch analysis

  1. Educational Leadership Effectiveness: A Rasch Analysis

    Science.gov (United States)

    Sinnema, Claire; Ludlow, Larry; Robinson, Viviane

    2016-01-01

    Purpose: The purposes of this paper are, first, to establish the psychometric properties of the ELP tool, and, second, to test, using a Rasch item response theory analysis, the hypothesized progression of challenge presented by the items included in the tool. Design/ Methodology/ Approach: Data were collected at two time points through a survey of…

  2. Competence-based employability: A Rasch analysis

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    Fröhlich, D.; Liu, M.; van der Heijden, B.

    2015-01-01

    Due to trends such as increasingly inter-organizational careers, the concept of employability is high on the agenda of employees, employers, and pol icy makers. To improve our understanding of this concept, we need to understand thoroughly its measurement. We performed a Rasch analysis of Van der

  3. Rasch analysis on OSCE data : An illustrative example.

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    Tor, E; Steketee, C

    2011-01-01

    The Objective Structured Clinical Examination (OSCE) is a widely used tool for the assessment of clinical competence in health professional education. The goal of the OSCE is to make reproducible decisions on pass/fail status as well as students' levels of clinical competence according to their demonstrated abilities based on the scores. This paper explores the use of the polytomous Rasch model in evaluating the psychometric properties of OSCE scores through a case study. The authors analysed an OSCE data set (comprised of 11 stations) for 80 fourth year medical students based on the polytomous Rasch model in an effort to answer two research questions: (1) Do the clinical tasks assessed in the 11 OSCE stations map on to a common underlying construct, namely clinical competence? (2) What other insights can Rasch analysis offer in terms of scaling, item analysis and instrument validation over and above the conventional analysis based on classical test theory? The OSCE data set has demonstrated a sufficient degree of fit to the Rasch model (Χ(2) = 17.060, DF=22, p=0.76) indicating that the 11 OSCE station scores have sufficient psychometric properties to form a measure for a common underlying construct, i.e. clinical competence. Individual OSCE station scores with good fit to the Rasch model (p > 0.1 for all Χ(2) statistics) further corroborated the characteristic of unidimensionality of the OSCE scale for clinical competence. A Person Separation Index (PSI) of 0.704 indicates sufficient level of reliability for the OSCE scores. Other useful findings from the Rasch analysis that provide insights, over and above the analysis based on classical test theory, are also exemplified using the data set. The polytomous Rasch model provides a useful and supplementary approach to the calibration and analysis of OSCE examination data.

  4. Rasch analysis on OSCE data : An illustrative example

    Directory of Open Access Journals (Sweden)

    Tor E

    2011-06-01

    Full Text Available BackgroundThe Objective Structured Clinical Examination (OSCE is awidely used tool for the assessment of clinical competencein health professional education. The goal of the OSCE is tomake reproducible decisions on pass/fail status as well asstudents’ levels of clinical competence according to theirdemonstrated abilities based on the scores. This paperexplores the use of the polytomous Rasch model inevaluating the psychometric properties of OSCE scoresthrough a case study.MethodThe authors analysed an OSCE data set (comprised of 11stations for 80 fourth year medical students based on thepolytomous Rasch model in an effort to answer tworesearch questions: (1 Do the clinical tasks assessed in the11 OSCE stations map on to a common underlyingconstruct, namely clinical competence? (2 What otherinsights can Rasch analysis offer in terms of scaling, itemanalysis and instrument validation over and above theconventional analysis based on classical test theory?ResultsThe OSCE data set has demonstrated a sufficient degree offit to the Rasch model (χ2 = 17.060, DF=22, p=0.76indicating that the 11 OSCE station scores have sufficientpsychometric properties to form a measure for a commonunderlying construct, i.e. clinical competence. IndividualOSCE station scores with good fit to the Rasch model (p >0.1 for all χ2 statistics further corroborated thecharacteristic of unidimensionality of the OSCE scale forclinical competence. A Person Separation Index (PSI of0.704 indicates sufficient level of reliability for the OSCEscores. Other useful findings from the Rasch analysis thatprovide insights, over and above the analysis based onclassical test theory, are also exemplified using the data set.ConclusionThe polytomous Rasch model provides a useful andsupplementary approach to the calibration and analysis ofOSCE examination data.

  5. Rasch analysis of professional behavior in medical education.

    Science.gov (United States)

    Lange, R; Verhulst, S J; Roberts, N K; Dorsey, J K

    2015-12-01

    The use of students' "consumer feedback" to assess faculty behavior and improve the process of medical education is a significant challenge. We used quantitative Rasch measurement to analyze pre-categorized student comments listed by 385 graduating medical students. We found that students differed little with respect to the number of comments they provided and that their comments indeed form a probabilistic Rasch hierarchy. However, different hierarchies were found across medical departments and faculty. An analysis of these interactions provides valuable, detailed, and quantitative information that can augment qualitative research approaches. In addition, we suggest how the Rasch scaling of student comments can assist researchers in the design and implementation of new faculty evaluation instruments. Finally, the interactions between student and department identified a subset of behaviors that appear to guide and possibly elicit students' comments.

  6. Rasch Analysis of the Geriatric Depression Scale--Short Form

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    Chiang, Karl S.; Green, Kathy E.; Cox, Enid O.

    2009-01-01

    Purpose: The purpose of this study was to examine scale dimensionality, reliability, invariance, targeting, continuity, cutoff scores, and diagnostic use of the Geriatric Depression Scale-Short Form (GDS-SF) over time with a sample of 177 English-speaking U.S. elders. Design and Methods: An item response theory, Rasch analysis, was conducted with…

  7. Rasch Analysis for Psychometric Improvement of Science Attitude Rating Scales

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    Oon, Pey-Tee; Fan, Xitao

    2017-01-01

    Students' attitude towards science (SAS) is often a subject of investigation in science education research. Survey of rating scale is commonly used in the study of SAS. The present study illustrates how Rasch analysis can be used to provide psychometric information of SAS rating scales. The analyses were conducted on a 20-item SAS scale used in an…

  8. A Rasch analysis between schizophrenic patients and the general population

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    Denis Frederic

    2017-10-01

    Full Text Available The aim of this study was to test the General Oral Health Assessment Index Questionnaire (GOHAI items for differential item functioning (DIF according to demographic characteristics (gender, age and mental health status (schizophrenic disorders versus general population using Rasch analysis.

  9. Rasch Analysis: A Primer for School Psychology Researchers and Practitioners

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    Boone, William J.; Noltemeyer, Amity

    2017-01-01

    In order to progress as a field, school psychology research must be informed by effective measurement techniques. One approach to address the need for careful measurement is Rasch analysis. This technique can (a) facilitate the development of instruments that provide useful data, (b) provide data that can be used confidently for both descriptive…

  10. Rasch analysis of the Dutch version of the Oxford elbow score

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    de Haan J

    2011-08-01

    Full Text Available Jeroen de Haan1, Niels Schep2, Wim Tuinebreijer2, Peter Patka2, Dennis den Hartog21Department of Surgery and Traumatology, Westfriesgasthuis, Hoorn, the Netherlands; 2Department of Surgery and Traumatology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the NetherlandsBackground: The Oxford elbow score (OES is a patient-rated, 12-item questionnaire that measures quality of life in relation to elbow disorders. This English questionnaire has been proven to be a reliable and valid instrument. Recently, the OES has been translated into Dutch and examined for its reliability, validity, and responsiveness in a group of Dutch patients with elbow pathology. The aim of this study was to analyze the Dutch version of the OES (OES-DV in combination with Rasch analysis or the one-parameter item response theory to examine the structure of the questionnaire.Methods: The OES-DV was administered to 103 patients (68 female, 35 male. The mean age of the patients was 44.3 ± 14.7 (range 15–75 years. Rasch analysis was performed using the Winsteps® Rasch Measurement Version 3.70.1.1 and a rating scale parameterization.Results: The person separation index, which is a measure of person reliability, was excellent (2.30. All the items of the OES had a reasonable mean square infit or outfit value between 0.6 and 1.7. The threshold of items were ordered, so the categories can function as intended. Principal component analysis of the residuals partly confirmed the multidimensionality of the English version of the OES. The OES distinguished 3.4 strata, which indicates that about three ranges can be differentiated.Conclusion: Rasch analysis of the OES-DV showed that the data fit to the stringent Rasch model. The multidimensionality of the English version of the OES was partly confirmed, and the four items of the function and three items of the pain domain were recognized as separate domains. The category rating scale of the OES-DV works well. The OES can

  11. Phylogenetic analysis of proteins involved in the stringent response in plant cells.

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    Ito, Doshun; Ihara, Yuta; Nishihara, Hidenori; Masuda, Shinji

    2017-07-01

    The nucleotide (p)ppGpp is a second messenger that controls the stringent response in bacteria. The stringent response modifies expression of a large number of genes and metabolic processes and allows bacteria to survive under fluctuating environmental conditions. Recent genome sequencing analyses have revealed that genes responsible for the stringent response are also found in plants. These include (p)ppGpp synthases and hydrolases, RelA/SpoT homologs (RSHs), and the pppGpp-specific phosphatase GppA/Ppx. However, phylogenetic relationship between enzymes involved in bacterial and plant stringent responses is as yet generally unclear. Here, we investigated the origin and evolution of genes involved in the stringent response in plants. Phylogenetic analysis and primary structures of RSH homologs from different plant phyla (including Embryophyta, Charophyta, Chlorophyta, Rhodophyta and Glaucophyta) indicate that RSH gene families were introduced into plant cells by at least two independent lateral gene transfers from the bacterial Deinococcus-Thermus phylum and an unidentified bacterial phylum; alternatively, they were introduced into a proto-plant cell by a lateral gene transfer from the endosymbiotic cyanobacterium followed by gene loss of an ancestral RSH gene in the cyanobacterial linage. Phylogenetic analysis of gppA/ppx families indicated that plant gppA/ppx homologs form an individual cluster in the phylogenetic tree, and show a sister relationship with some bacterial gppA/ppx homologs. Although RSHs contain a plastidial transit peptide at the N terminus, GppA/Ppx homologs do not, suggesting that plant GppA/Ppx homologs function in the cytosol. These results reveal that a proto-plant cell obtained genes for the stringent response by lateral gene transfer events from different bacterial phyla and have utilized them to control metabolism in plastids and the cytosol.

  12. Rasch Analysis of Lebanese Nurses’ Responses to the EIS Questionnaire

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    Michael Clinton

    2014-08-01

    Full Text Available This study examined the psychometric characteristics of a 32-item modified version of the Ethical Issues Scale (EIS. Data were collected from 59 registered nurses at the American University of Beirut Medical Centre (AUBMC. Data were analyzed using WINSTEPS Rasch analysis software. The four-category EIS rating scale needs modification for future studies in Lebanon. All EIS scale items need rewording prior to translation into Arabic to avoid confusion among Lebanese nurses. Principal component analysis (PCA of residuals indicated the possible presence of additional dimensions. Additional EIS items are needed to improve targeting.

  13. Examination of a social-networking site activities scale (SNSAS) using Rasch analysis

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    Alhaythami, Hassan; Karpinski, Aryn; Kirschner, Paul A.; Bolden, Edward

    2018-01-01

    This study examined the psychometric properties of a socialnetworking site (SNS) activities scale using Rasch Analysis. Items were also examined with Rasch Principal Components Analysis (PCA) and Differential Item Functioning (DIF) across groups of university students (i.e., males and females from

  14. Psychometric Properties on Lecturers' Beliefs on Teaching Function: Rasch Model Analysis

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    Mofreh, Samah Ali Mohsen; Ghafar, Mohammed Najib Abdul; Omar, Abdul Hafiz Hj; Mosaku, Monsurat; Ma'ruf, Amar

    2014-01-01

    This paper focuses on the psychometric analysis of lecturers' beliefs on teaching function (LBTF) survey using Rasch Model analysis. The sample comprised 34 Community Colleges' lecturers. The Rasch Model is applied to produce specific measurements on the lecturers' beliefs on teaching function in order to generalize results and inferential…

  15. Rasch Analysis of the Fullerton Advanced Balance (FAB) Scale

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    Fiedler, Roger C.; Rose, Debra J.

    2011-01-01

    ABSTRACT Purpose: This cross-sectional study explores the psychometric properties and dimensionality of the Fullerton Advanced Balance (FAB) Scale, a multi-item balance test for higher-functioning older adults. Methods: Participants (n=480) were community-dwelling adults able to ambulate independently. Data gathering consisted of survey and balance performance assessment. Psychometric properties were assessed using Rasch analysis. Results: Mean age of participants was 76.4 (SD=7.1) years. Mean FAB Scale scores were 24.7/40 (SD=7.5). Analyses for scale dimensionality showed that 9 of the 10 items fit a unidimensional measure of balance. Item 10 (Reactive Postural Control) did not fit the model. The reliability of the scale to separate persons was 0.81 out of 1.00; the reliability of the scale to separate items in terms of their difficulty was 0.99 out of 1.00. Cronbach's alpha for a 10-item model was 0.805. Items of differing difficulties formed a useful ordinal hierarchy for scaling patterns of expected balance ability scoring for a normative population. Conclusion: The FAB Scale appears to be a reliable and valid tool to assess balance function in higher-functioning older adults. The test was found to discriminate among participants of varying balance abilities. Further exploration of concurrent validity of Rasch-generated expected item scoring patterns should be undertaken to determine the test's diagnostic and prescriptive utility. PMID:22210989

  16. Rasch Analysis of the Fullerton Advanced Balance (FAB) Scale.

    Science.gov (United States)

    Klein, Penelope J; Fiedler, Roger C; Rose, Debra J

    2011-01-01

    This cross-sectional study explores the psychometric properties and dimensionality of the Fullerton Advanced Balance (FAB) Scale, a multi-item balance test for higher-functioning older adults. Participants (n=480) were community-dwelling adults able to ambulate independently. Data gathering consisted of survey and balance performance assessment. Psychometric properties were assessed using Rasch analysis. Mean age of participants was 76.4 (SD=7.1) years. Mean FAB Scale scores were 24.7/40 (SD=7.5). Analyses for scale dimensionality showed that 9 of the 10 items fit a unidimensional measure of balance. Item 10 (Reactive Postural Control) did not fit the model. The reliability of the scale to separate persons was 0.81 out of 1.00; the reliability of the scale to separate items in terms of their difficulty was 0.99 out of 1.00. Cronbach's alpha for a 10-item model was 0.805. Items of differing difficulties formed a useful ordinal hierarchy for scaling patterns of expected balance ability scoring for a normative population. The FAB Scale appears to be a reliable and valid tool to assess balance function in higher-functioning older adults. The test was found to discriminate among participants of varying balance abilities. Further exploration of concurrent validity of Rasch-generated expected item scoring patterns should be undertaken to determine the test's diagnostic and prescriptive utility.

  17. Psychometric analysis of the Self-Harm Inventory using Rasch modelling

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    Cumming Steven R

    2009-08-01

    Full Text Available Abstract Background Deliberate Self-Harm (DSH is the intentional destruction of healthy body tissue without suicidal intent. DSH behaviours in non-clinical populations vary, and instruments containing a range of behaviours may be more informative than ones with restricted content. The Self-Harm Inventory (SHI is a widely used measure of DSH in clinical populations (mental and physical health and covers a broad range of behaviours (self-injury, risk taking and self-defeating acts. The test authors recommend the SHI to screen for Borderline Personality Disorder (BPD using a cut-off score of five or more. The aim of this study was to investigate the psychometric characteristics of the SHI in non-clinical samples. Methods The SHI was administered to a sample of 423 non-clinical participants (university students, age range 17 to 30. External validation was informed by the administration of the Depression Anxiety Stress Scales 21 (DASS-21 to a sub-sample (n = 221. Rasch analysis of the SHI was conducted to provide a stringent test of unidimensionality and to identify the DSH behaviours most likely to be endorsed at each total score. Results The SHI showed adequate fit to the Rasch model and no modifications were required following checks of local response dependency, differential item functioning and unidimensionality. The scale identified gender and age differences in scores, with females and older participants reporting higher levels of DSH. SHI scores and DASS-21 scores were related. Conclusion The recommended cut-off point of five is likely to comprise mild forms of DSH and may not be indicative of psychopathology in a non-clinical population. Rather it may be more indicative of developmentally related risk taking behaviours while a higher cut-off point may be more suggestive of psychopathology as indicated by higher levels of depression, stress and anxiety.

  18. Modern psychometrics for assessing achievement goal orientation: a Rasch analysis.

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    Muis, Krista R; Winne, Philip H; Edwards, Ordene V

    2009-09-01

    A program of research is needed that assesses the psychometric properties of instruments designed to quantify students' achievement goal orientations to clarify inconsistencies across previous studies and to provide a stronger basis for future research. We conducted traditional psychometric and modern Rasch-model analyses of the Achievement Goals Questionnaire (AGQ, Elliot & McGregor, 2001) and the Patterns of Adaptive Learning Scale (PALS, Midgley et al., 2000) to provide an in-depth analysis of the two most popular instruments in educational psychology. For Study 1, 217 undergraduate students enrolled in educational psychology courses participated. Thirty-four were male and 181 were female (two did not respond). Participants completed the AGQ in the context of their educational psychology class. For Study 2, 126 undergraduate students enrolled in educational psychology courses participated. Thirty were male and 95 were female (one did not respond). Participants completed the PALS in the context of their educational psychology class. Traditional psychometric assessments of the AGQ and PALS replicated previous studies. For both, reliability estimates ranged from good to very good for raw subscale scores and fit for the models of goal orientations were good. Based on traditional psychometrics, the AGQ and PALS are valid and reliable indicators of achievement goals. Rasch analyses revealed that estimates of reliability for items were very good but respondent ability estimates varied from poor to good for both the AGQ and PALS. These findings indicate that items validly and reliably reflect a group's aggregate goal orientation, but using either instrument to characterize an individual's goal orientation is hazardous.

  19. The Revised Body Awareness Rating Questionnaire: Development Into a Unidimensional Scale Using Rasch Analysis.

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    Dragesund, Tove; Strand, Liv Inger; Grotle, Margreth

    2018-02-01

    The Body Awareness Rating Questionnaire (BARQ) is a self-report questionnaire aimed at capturing how people with long-lasting musculoskeletal pain reflect on their own body awareness. Methods based on classical test theory were applied to the development of the instrument and resulted in 4 subscales. However, the scales were not correlated, and construct validity might be questioned. The primary purpose of this study was to explore the possibility of developing a unidimensional scale from items initially collected for the BARQ using Rasch analysis. A secondary purpose was to investigate the test-retest reliability of a revised version of the BARQ. This was a methodological study. Rasch and reliability analyses were performed for 3 samples of participants with long-lasting musculoskeletal pain. The first Rasch analysis was carried out on 66 items generated for the original BARQ and scored by 300 participants. The items supported by the first analysis were scored by a new group of 127 participants and analyzed in a second Rasch analysis. For the test-retest reliability analysis, 48 participants scored the revised BARQ items twice within 1 week. The 2-step Rasch analysis resulted in a unidimensional 12-item revised version of the BARQ with a 4-point response scale (scores from 0 to 36). It showed a good fit to the Rasch model, with acceptable internal consistency, satisfactory fit residuals, and no disordered thresholds. Test-retest reliability was high, with an intraclass correlation coefficient of .83 (95% CI = .71-.89) and a smallest detectable change of 6.3 points. The small sample size in the second Rasch analysis was a study limitation. The revised BARQ is a unidimensional and feasible measurement of body awareness, recommended for use in the context of body-mind physical therapy approaches for musculoskeletal conditions.

  20. Analysis of local dependence and multidimensionality in graphical loglinear Rasch models

    DEFF Research Database (Denmark)

    Kreiner, Svend; Christensen, Karl Bang

    local independence; multidimensionality, differential item functioning; uniform local dependency and DIF; graphical Rasch models; loglinear Rasch models......local independence; multidimensionality, differential item functioning; uniform local dependency and DIF; graphical Rasch models; loglinear Rasch models...

  1. Analysis of Local Dependence and Multidimensionality in Graphical Loglinear Rasch Models

    DEFF Research Database (Denmark)

    Kreiner, Svend; Christensen, Karl Bang

    2004-01-01

    Local independence; Multidimensionality; Differential item functioning; Uniform local dependence and DIF; Graphical Rasch models; Loglinear Rasch model......Local independence; Multidimensionality; Differential item functioning; Uniform local dependence and DIF; Graphical Rasch models; Loglinear Rasch model...

  2. Acceptance on Mobile Learning via SMS: A Rasch Model Analysis

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    Issham Ismail

    2010-04-01

    Full Text Available This study investigated whether mobile learning via Short Message Service (SMS-learning is accepted by the students enrolled in the distance learning academic programme in the Universiti Sains Malaysia. This study explored the impact of perceived usefulness, perceived ease of use and usability of the system to their acceptability. The survey was constructed using a questionnaire consisting of statements regarding the participants’ demographics, experiences in and perception of using mobile learning via SMS, involving 105 students from management and sciences disciplines. The Rasch Model Analysis was used for measurement correspond to a 5 point Likert. Results indicated that the usability of the system contributed to be effectiveness in assisting the students with their study. Respondents agree that SMS-learning is easy, effective and useful to help them study. However, the results found that there has been a problem in mobile learning that less interaction with lecturers. It implies that the acceptability of students to this mode on communication and interaction is highly endorsed.

  3. Understanding metallic bonding: Structure, process and interaction by Rasch analysis

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    Cheng, Maurice M. W.; Oon, Pey-Tee

    2016-08-01

    This paper reports the results of a survey of 3006 Year 10-12 students on their understandings of metallic bonding. The instrument was developed based on Chi's ontological categories of scientific concepts and students' understanding of metallic bonding as reported in the literature. The instrument has two parts. Part one probed into students' understanding of metallic bonding as (a) a submicro structure of metals, (b) a process in which individual metal atoms lose their outermost shell electrons to form a 'sea of electrons' and octet metal cations or (c) an all-directional electrostatic force between delocalized electrons and metal cations, that is, an interaction. Part two assessed students' explanation of malleability of metals, for example (a) as a submicro structural rearrangement of metal atoms/cations or (b) based on all-directional electrostatic force. The instrument was validated by the Rasch Model. Psychometric assessment showed that the instrument possessed reasonably good properties of measurement. Results revealed that it was reliable and valid for measuring students' understanding of metallic bonding. Analysis revealed that the structure, process and interaction understandings were unidimensional and in an increasing order of difficulty. Implications for the teaching of metallic bonding, particular through the use of diagrams, critiques and model-based learning, are discussed.

  4. Analysis of High School German Textbooks through Rasch Measurement Model

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    Batdi, Veli; Elaldi, Senel

    2016-01-01

    The purpose of the present study is to analyze German teacher trainers' views on high school German textbooks through the Rasch measurement model. A survey research design was employed and study group consisted of a total of 21 teacher trainers, three from each region and selected randomly from provinces which are located in seven regions and…

  5. Modern Psychometrics for Assessing Achievement Goal Orientation: A Rasch Analysis

    Science.gov (United States)

    Muis, Krista R.; Winne, Philip H.; Edwards, Ordene V.

    2009-01-01

    Background: A program of research is needed that assesses the psychometric properties of instruments designed to quantify students' achievement goal orientations to clarify inconsistencies across previous studies and to provide a stronger basis for future research. Aim: We conducted traditional psychometric and modern Rasch-model analyses of the…

  6. Rasch Analysis of Professional Behavior in Medical Education

    Science.gov (United States)

    Lange, R.; Verhulst, S. J.; Roberts, N. K.; Dorsey, J. K.

    2015-01-01

    The use of students' "consumer feedback" to assess faculty behavior and improve the process of medical education is a significant challenge. We used quantitative Rasch measurement to analyze pre-categorized student comments listed by 385 graduating medical students. We found that students differed little with respect to the number of…

  7. Validation of the voice handicap index using Rasch analysis

    NARCIS (Netherlands)

    Bogaardt, H. C. A.; Hakkesteegt, M. M.; Grolman, W.; Lindeboom, R.

    2007-01-01

    BACKGROUND: The Voice Handicap Index is a tool for measuring the psychosocial consequences of voice disorders and consists of three dimensions. Previous psychometric evaluation of the VHI focused on the classic evaluation of reliability and validity, which is sample dependent. The authors used Rasch

  8. Multidimensional fatigue inventory and post-polio syndrome - a Rasch analysis.

    Science.gov (United States)

    Dencker, Anna; Sunnerhagen, Katharina S; Taft, Charles; Lundgren-Nilsson, Åsa

    2015-02-12

    Fatigue is a common symptom in post-polio syndrome (PPS) and can have a substantial impact on patients. There is a need for validated questionnaires to assess fatigue in PPS for use in clinical practice and research. The aim with this study was to assess the validity and reliability of the Swedish version of Multidimensional Fatigue Inventory (MFI-20) in patients with PPS using the Rasch model. A total of 231 patients diagnosed with PPS completed the Swedish MFI-20 questionnaire at post-polio out-patient clinics in Sweden. The mean age of participants was 62 years and 61% were females. Data were tested against assumptions of the Rasch measurement model (i.e. unidimensionality of the scale, good item fit, independency of items and absence of differential item functioning). Reliability was tested with the person separation index (PSI). A transformation of the ordinal total scale scores into an interval scale for use in parametric analysis was performed. Dummy cases with minimum and maximum scoring were used for the transformation table to achieve interval scores between 20 and 100, which are comprehensive limits for the MFI-20 scale. An initial Rasch analysis of the full scale with 20 items showed misfit to the Rasch model (p post-polio syndrome. The Rasch transformed total scores can be used for parametric statistical analyses in future clinical studies.

  9. Rasch analysis of the hospital anxiety and depression scale among Chinese cataract patients.

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    Xianchai Lin

    Full Text Available To analyze the validity of the Hospital Anxiety and Depression Scale (HADS among Chinese cataract population.A total of 275 participants with unilateral or bilateral cataract were recruited to complete the Chinese version of HADS. The patients' demographic and ophthalmic characteristics were documented. Rasch analysis was conducted to examine the model fit statistics, the thresholds ordering of the polytomous items, targeting, person separation index and reliability, local dependency, unidimentionality, differential item functioning (DIF and construct validity of the HADS individual and summary measures.Rasch analysis was performed on anxiety and depression subscales as well as HADS-Total score respectively. The items of original HADS-Anxiety, HADS-Depression and HADS-Total demonstrated evidence of misfit of the Rasch model. Removing items A7 for anxiety subscale and rescoring items D14 for depression subscale significantly improved Rasch model fit. A 12-item higher order total scale with further removal of D12 was found to fit the Rasch model. The modified items had ordered response thresholds. No uniform DIF was detected, whereas notable non-uniform DIF in high-ability group was found. The revised cut-off points were given for the modified anxiety and depression subscales.The modified version of HADS with HADS-A and HADS-D as subscale and HADS-T as a higher-order measure is a reliable and valid instrument that may be useful for assessing anxiety and depression states in Chinese cataract population.

  10. Obtaining Content Weights for Test Specifications from Job Analysis Task Surveys: An Application of the Many-Facets Rasch Model

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    Wang, Ning; Stahl, John

    2012-01-01

    This article discusses the use of the Many-Facets Rasch Model, via the FACETS computer program (Linacre, 2006a), to scale job/practice analysis survey data as well as to combine multiple rating scales into single composite weights representing the tasks' relative importance. Results from the Many-Facets Rasch Model are compared with those…

  11. An Analysis of Cross Racial Identity Scale Scores Using Classical Test Theory and Rasch Item Response Models

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    Sussman, Joshua; Beaujean, A. Alexander; Worrell, Frank C.; Watson, Stevie

    2013-01-01

    Item response models (IRMs) were used to analyze Cross Racial Identity Scale (CRIS) scores. Rasch analysis scores were compared with classical test theory (CTT) scores. The partial credit model demonstrated a high goodness of fit and correlations between Rasch and CTT scores ranged from 0.91 to 0.99. CRIS scores are supported by both methods.…

  12. Is the pain visual analogue scale linear and responsive to change? An exploration using Rasch analysis.

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    Paula Kersten

    Full Text Available OBJECTIVES: Pain visual analogue scales (VAS are commonly used in clinical trials and are often treated as an interval level scale without evidence that this is appropriate. This paper examines the internal construct validity and responsiveness of the pain VAS using Rasch analysis. METHODS: Patients (n = 221, mean age 67, 58% female with chronic stable joint pain (hip 40% or knee 60% of mechanical origin waiting for joint replacement were included. Pain was scored on seven daily VASs. Rasch analysis was used to examine fit to the Rasch model. Responsiveness (Standardized Response Means, SRM was examined on the raw ordinal data and the interval data generated from the Rasch analysis. RESULTS: Baseline pain VAS scores fitted the Rasch model, although 15 aberrant cases impacted on unidimensionality. There was some local dependency between items but this did not significantly affect the person estimates of pain. Daily pain (item difficulty was stable, suggesting that single measures can be used. Overall, the SRMs derived from ordinal data overestimated the true responsiveness by 59%. Changes over time at the lower and higher end of the scale were represented by large jumps in interval equivalent data points; in the middle of the scale the reverse was seen. CONCLUSIONS: The pain VAS is a valid tool for measuring pain at one point in time. However, the pain VAS does not behave linearly and SRMs vary along the trait of pain. Consequently, Minimum Clinically Important Differences using raw data, or change scores in general, are invalid as these will either under- or overestimate true change; raw pain VAS data should not be used as a primary outcome measure or to inform parametric-based Randomised Controlled Trial power calculations in research studies; and Rasch analysis should be used to convert ordinal data to interval data prior to data interpretation.

  13. Is the Pain Visual Analogue Scale Linear and Responsive to Change? An Exploration Using Rasch Analysis

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    Kersten, Paula; White, Peter J.; Tennant, Alan

    2014-01-01

    Objectives Pain visual analogue scales (VAS) are commonly used in clinical trials and are often treated as an interval level scale without evidence that this is appropriate. This paper examines the internal construct validity and responsiveness of the pain VAS using Rasch analysis. Methods Patients (n = 221, mean age 67, 58% female) with chronic stable joint pain (hip 40% or knee 60%) of mechanical origin waiting for joint replacement were included. Pain was scored on seven daily VASs. Rasch analysis was used to examine fit to the Rasch model. Responsiveness (Standardized Response Means, SRM) was examined on the raw ordinal data and the interval data generated from the Rasch analysis. Results Baseline pain VAS scores fitted the Rasch model, although 15 aberrant cases impacted on unidimensionality. There was some local dependency between items but this did not significantly affect the person estimates of pain. Daily pain (item difficulty) was stable, suggesting that single measures can be used. Overall, the SRMs derived from ordinal data overestimated the true responsiveness by 59%. Changes over time at the lower and higher end of the scale were represented by large jumps in interval equivalent data points; in the middle of the scale the reverse was seen. Conclusions The pain VAS is a valid tool for measuring pain at one point in time. However, the pain VAS does not behave linearly and SRMs vary along the trait of pain. Consequently, Minimum Clinically Important Differences using raw data, or change scores in general, are invalid as these will either under- or overestimate true change; raw pain VAS data should not be used as a primary outcome measure or to inform parametric-based Randomised Controlled Trial power calculations in research studies; and Rasch analysis should be used to convert ordinal data to interval data prior to data interpretation. PMID:24921952

  14. Analysis of letter name knowledge using Rasch measurement.

    Science.gov (United States)

    Bowles, Ryan P; Skibbe, Lori E; Justice, Laura M

    2011-01-01

    Letter name knowledge (LNK) is a key predictor of later reading ability and has been emphasized strongly in recent educational policy. Studies of LNK have implicitly treated it as a unidimensional construct with all letters equally relevant to its measurement. However, some empirical research suggests that contextual factors can affect the measurement of LNK. In this study, we analyze responses from 909 children on measures of LNK using the Rasch model and its extensions, and consider two contextual factors: the format of assessment and the own-name advantage, which states that children are more likely to know letters in their own first names. Results indicate that both contextual factors have important impacts on measurement and that LNK does not meet the requirements of Rasch measurement even when accounting for the contextual factors. These findings introduce philosophical concerns for measurement of constrained skills which have limited content for assessment.

  15. Rasch analysis of the 23-item version of the Roland Morris Disability Questionnaire

    DEFF Research Database (Denmark)

    Kent, Peter; Grotle, Margreth; Dunn, Kate M

    2015-01-01

    -based approach that includes consideration of new items and response options; or (ii) the use of alternative questionnaires should be recommended, such as the Oswestry Disability Index, that have shown evidence of fitting the Rasch model; or (iii) a completely new condition-specific questionnaire should......OBJECTIVE: To determine the psychometric properties of the 23-item version of the Roland Morris Disability Questionnaire (RMDQ-23) and to quantify their stability across 2 cultures/languages and 2 types of care-settings. METHODS: Rasch analysis of data from 1,000 patients with low back pain from...

  16. On the Construct Validity of the Academic Motivation Scale: a CFA and Rasch Analysis approach

    DEFF Research Database (Denmark)

    Andersen, Martin Stolpe; Nielsen, Tine

    investigated using confirmatory factor analysis with mixed results of some acceptable and some non-acceptable fit indices for the model. Secondly, Rasch analyses were conducted for each of the seven subscales, using the partial credit model (PCM) and graphical loglinear rasch models (GLLRM). This resulted...... in fit to the PCM in the case of IM to Accomplish (retaining three out of four items), and fit to GLLRMs in two cases: 1) IM to know with evidence of local dependence between all four items. 2) AM (retaining three out of four items) with evidence of gender-based differential item functioning, which...

  17. A Rasch Analysis of the Junior Metacognitive Awareness Inventory with Singapore Students

    Science.gov (United States)

    Ning, Hoi Kwan

    2018-01-01

    The psychometric properties of the 2 versions of the Junior Metacognitive Awareness Inventory were examined with Singapore student samples. Other than 2 misfitting items and an underutilized response scale, Rasch analysis demonstrated that the instruments have good measurement precision, and no differential item functioning was detected across…

  18. Rasch analysis of the London Handicap Scale in stroke patients: a cross-sectional study.

    Science.gov (United States)

    Park, Eun-Young; Choi, Yoo-Im

    2014-07-31

    Although activity and participation are the target domains in stroke rehabilitation interventions, there is insufficient evidence available regarding the validity of participation measurement. The purpose of this study was to investigate the psychometric properties of the London Handicap Scale in community-dwelling stroke patients, using Rasch analysis. Participants were 170 community-dwelling stroke survivors. The data were analyzed using Winsteps (version 3.62) with the Rasch model to determine the unidimensionality of item fit, the distribution of item difficulty, and the reliability and suitability of the rating process for the London Handicap Scale. Data of 16 participants did not fit the Rasch model and there were no misfitting items. The person separation value was 2.42, and the reliability was .85; furthermore, the rating process for the London Handicap Scale was found to be suitable for use with stroke patients. This was the first trial to investigate the psychometric properties of the London Handicap Scale using Rasch analysis; the results supported the suitability of this scale for use with stroke patients.

  19. Rasch Analysis of the Wrist and Hand Fugl-Meyer: Dimensionality and Item-Level Characteristics.

    Science.gov (United States)

    Persch, Andrew C; Gugiu, P Cristian; Velozo, Craig A; Page, Stephen J

    2015-07-01

    Clinical administration of the wrist stability, wrist mobility, and hand items of the upper-extremity Fugl-Meyer (W/H UE FM) may provide a rigorous, easily administered, bedside measure of motor impairment in mildly impaired stroke survivors. The purpose of this study was to evaluate the item structure of the W/H UE FM to better understand its measurement properties using Rasch analysis. This was a secondary analysis of W/H UE FM data arising from clinical trials of mildly impaired stroke survivors using latent parallel analysis, ordinal factor analysis, and partial credit model Rasch analyses. Latent parallel analysis and ordinal factor analysis indicated that all W/H UE FM items represent a single unidimensional construct, wrist and hand motor ability. Rasch analysis of data from 150 mildly impaired stroke survivors (94 men; mean age, 57.1 ± 11.4 years; mean time since stroke, 19.5 months) revealed that the W/H UE FM operated as a reliable, valid, and effective measure of wrist and hand motor ability. These data were compatible with Rasch model assumptions and are consistent with previous W/H UE FM research. Mass flexion and extension movements were the least difficult W/H UE FM items while the radial and hook grasp items were the most difficult. The W/H UE FM is well suited to mildly impaired stroke survivors who exhibit the ability to perform mass flexion and mass extension movements. The full-scale UE FM may be preferable for stroke survivors with lower levels of ability.Video abstract available for additional insight from the authors (Supplemental Digital Content 1, http://links.lww.com/JNPT/A108).

  20. Rasch analysis suggested three unidimensional domains for Affiliate Stigma Scale: additional psychometric evaluation.

    Science.gov (United States)

    Chang, Chih-Cheng; Su, Jian-An; Tsai, Ching-Shu; Yen, Cheng-Fang; Liu, Jiun-Horng; Lin, Chung-Ying

    2015-06-01

    To examine the psychometrics of the Affiliate Stigma Scale using rigorous psychometric analysis: classical test theory (CTT) (traditional) and Rasch analysis (modern). Differential item functioning (DIF) items were also tested using Rasch analysis. Caregivers of relatives with mental illness (n = 453; mean age: 53.29 ± 13.50 years) were recruited from southern Taiwan. Each participant filled out four questionnaires: Affiliate Stigma Scale, Rosenberg Self-Esteem Scale, Beck Anxiety Inventory, and one background information sheet. CTT analyses showed that the Affiliate Stigma Scale had satisfactory internal consistency (α = 0.85-0.94) and concurrent validity (Rosenberg Self-Esteem Scale: r = -0.52 to -0.46; Beck Anxiety Inventory: r = 0.27-0.34). Rasch analyses supported the unidimensionality of three domains in the Affiliate Stigma Scale and indicated four DIF items (affect domain: 1; cognitive domain: 3) across gender. Our findings, based on rigorous statistical analysis, verified the psychometrics of the Affiliate Stigma Scale and reported its DIF items. We conclude that the three domains of the Affiliate Stigma Scale can be separately used and are suitable for measuring the affiliate stigma of caregivers of relatives with mental illness. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. A Rasch analysis of nurses' ethical sensitivity to the norms of the code of conduct.

    Science.gov (United States)

    González-de Paz, Luis; Kostov, Belchin; Sisó-Almirall, Antoni; Zabalegui-Yárnoz, Adela

    2012-10-01

    To develop an instrument to measure nurses' ethical sensitivity and, secondarily, to use this instrument to compare nurses' ethical sensitivity between groups. Professional codes of conduct are widely accepted guidelines. However, their efficacy in daily nursing practice and influence on ethical sensitivity is controversial. A descriptive cross-sectional study was conducted. One hundred and forty-three registered nurses from Barcelona (Spain) participated in the study, of whom 45.83% were working in primary health care and 53.84% in hospital wards. A specifically designed confidential, self-administered questionnaire assessing ethical sensitivity was developed. Knowledge of the nursing code and data on ethical sensitivity were summarised, with the quality of the questionnaire assessed using Rasch analysis. Item on knowledge of the code showed that one-third of nurses knew the contents of the code and two-thirds had limited knowledge. To fit the Rasch model, it was necessary to rescore the rating scale from five to three categories. Residual principal components analysis confirmed the unidimensionality of the scale. Three items of the questionnaire presented fit problems with the Rasch model. Although nurses generally have high ethical sensitivity to their code of conduct, differences were found according to years of professional practice, place of work and knowledge of the code (pcode was high. However, many factors might influence the degree of ethical sensitivity. Further research to measure ethical sensitivity using invariant measures such as Rasch units would be valuable. Other factors, such as assertiveness or courage, should be considered to improve ethical sensitivity to the code of conduct. Rigorous measurement studies and analysis in applied ethics are needed to assess ethical performance in practice. © 2012 Blackwell Publishing Ltd.

  2. Psychometric evaluation of the revised Illness Perception Questionnaire (IPQ-R) in cancer patients: confirmatory factor analysis and Rasch analysis.

    Science.gov (United States)

    Ashley, Laura; Smith, Adam B; Keding, Ada; Jones, Helen; Velikova, Galina; Wright, Penny

    2013-12-01

    To provide new insights into the psychometrics of the revised Illness Perception Questionnaire (IPQ-R) in cancer patients. To undertake, for the first time using data from breast, colorectal and prostate cancer patients, a confirmatory factor analysis (CFA) to assess the validity of the IPQ-R's core seven-factor structure. Also, for the first time in any illness group, to undertake Rasch analysis to explore the extent to which the IPQ-R factors form unidimensional scales, with linear measurement properties and no Differential Item Functioning (DIF). Patients with potentially curable breast, colorectal or prostate cancer, within 6months post-diagnosis, completed the IPQ-R online (N=531). CFA was conducted, including multi-sample analysis, and for each IPQ-R factor fit to the Rasch model was assessed by examining, amongst other things, item fit, DIF and unidimensionality. The CFA showed a moderate fit of the data to the IPQ-R model, and stability across diagnosis, although fit was significantly improved following the removal of selected items. All seven factors achieved fit to the Rasch model, and exhibited unidimensionality and minimal DIF, although in most cases this was after some item rescoring and/or deletion. In both analyses, IPQ-R items 12, 18 and 24 were indicated as misfitting and removed. Given the rigorous standard of Rasch measurement, and the generic nature of the IPQ-R, it stood up well to the demands of the Rasch model in this study. Importantly, the results show that with some relatively minor, pragmatic modifications the IPQ-R could possess Rasch-standard measurement in cancer patients. © 2013.

  3. Improvement of the Van Lieshout hand function test for tetraplegia using a Rasch analysis.

    Science.gov (United States)

    Spooren, A I F; Arnould, C; Smeets, R J E M; Bongers, H M H; Seelen, H A M

    2013-10-01

    Cross-sectional study. The Van Lieshout hand function test for tetraplegia (VLT) measures the quality of arm-hand functioning in persons with tetraplegia. It is valid, reliable and responsive. However, it does not satisfy all the criteria for interval level measurement. The present study aims to apply the Rasch model to the VLT short form (VLT-SF) to upgrade its scale type towards interval level, and to verify if the requirements of an objective measure are satisfied in the revised version. Eight Dutch Rehabilitation centres. The VLT-SF data of 73 tetraplegic patients were Rasch-analysed (RUMM2030 software, RUMM Laboratory Pty Ltd, Perth, Australia) to verify the order of response categories, unidimensionality and reliability of the VLT-SF, and to assess its applicability regardless of (motor) lesion completeness. Seven of the ten VLT-SF items showed disordered response categories. The six original response categories were therefore recoded into three or four categories. After recoding, all items satisfied the model requirement of unidimensionality. The items were relatively well-targeted on the subjects' arm-hand skilled performance measures, leading to a good person separation index (R=0.91). The difficulty hierarchy of the VLT-SF items was invariant across patient subgroups of (motor) lesion completeness. Provided that response categories are recoded, VLT-SF Rasch analysis showed that the requirements of an objective measure were satisfied. This allows to compare the measurements of different patients quantitatively, and to follow their results over time.

  4. Validating Quantitative Measurement Using Qualitative Data: Combining Rasch Scaling and Latent Semantic Analysis in Psychiatry

    Science.gov (United States)

    Lange, Rense

    2015-02-01

    An extension of concurrent validity is proposed that uses qualitative data for the purpose of validating quantitative measures. The approach relies on Latent Semantic Analysis (LSA) which places verbal (written) statements in a high dimensional semantic space. Using data from a medical / psychiatric domain as a case study - Near Death Experiences, or NDE - we established concurrent validity by connecting NDErs qualitative (written) experiential accounts with their locations on a Rasch scalable measure of NDE intensity. Concurrent validity received strong empirical support since the variance in the Rasch measures could be predicted reliably from the coordinates of their accounts in the LSA derived semantic space (R2 = 0.33). These coordinates also predicted NDErs age with considerable precision (R2 = 0.25). Both estimates are probably artificially low due to the small available data samples (n = 588). It appears that Rasch scalability of NDE intensity is a prerequisite for these findings, as each intensity level is associated (at least probabilistically) with a well- defined pattern of item endorsements.

  5. Emotional Intelligence and Nurse Recruitment: Rasch and confirmatory factor analysis of the trait emotional intelligence questionnaire short form.

    Science.gov (United States)

    Snowden, Austyn; Watson, Roger; Stenhouse, Rosie; Hale, Claire

    2015-12-01

    To examine the construct validity of the Trait Emotional Intelligence Questionnaire Short form. Emotional intelligence involves the identification and regulation of our own emotions and the emotions of others. It is therefore a potentially useful construct in the investigation of recruitment and retention in nursing and many questionnaires have been constructed to measure it. Secondary analysis of existing dataset of responses to Trait Emotional Intelligence Questionnaire Short form using concurrent application of Rasch analysis and confirmatory factor analysis. First year undergraduate nursing and computing students completed Trait Emotional Intelligence Questionnaire-Short Form in September 2013. Responses were analysed by synthesising results of Rasch analysis and confirmatory factor analysis. Participants (N = 938) completed Trait Emotional Intelligence Questionnaire Short form. Rasch analysis showed the majority of the Trait Emotional Intelligence Questionnaire-Short Form items made a unique contribution to the latent trait of emotional intelligence. Five items did not fit the model and differential item functioning (gender) accounted for this misfit. Confirmatory factor analysis revealed a four-factor structure consisting of: self-confidence, empathy, uncertainty and social connection. All five misfitting items from the Rasch analysis belonged to the 'social connection' factor. The concurrent use of Rasch and factor analysis allowed for novel interpretation of Trait Emotional Intelligence Questionnaire Short form. Much of the response variation in Trait Emotional Intelligence Questionnaire Short form can be accounted for by the social connection factor. Implications for practice are discussed. © 2015 John Wiley & Sons Ltd.

  6. A rapid response air quality analysis system for use in projects having stringent quality assurance requirements

    International Nuclear Information System (INIS)

    Bowman, A.W.

    1990-01-01

    This paper describes an approach to solve air quality problems which frequently occur during iterations of the baseline change process. From a schedule standpoint, it is desirable to perform this evaluation in as short a time as possible while budgetary pressures limit the size of the staff available to do the work. Without a method in place to deal with baseline change proposal requests the environment analysts may not be able to produce the analysis results in the time frame expected. Using a concept called the Rapid Response Air Quality Analysis System (RAAS), the problems of timing and cost become tractable. The system could be adapted to assess other atmospheric pathway impacts, e.g., acoustics or visibility. The air quality analysis system used to perform the EA analysis (EA) for the Salt Repository Project (part of the Civilian Radioactive Waste Management Program), and later to evaluate the consequences of proposed baseline changes, consists of three components: Emission source data files; Emission rates contained in spreadsheets; Impact assessment model codes. The spreadsheets contain user-written codes (macros) that calculate emission rates from (1) emission source data (e.g., numbers and locations of sources, detailed operating schedules, and source specifications including horsepower, load factor, and duty cycle); (2) emission factors such as those published by the U.S. Environmental Protection Agency, and (3) control efficiencies

  7. A Rasch and confirmatory factor analysis of the General Health Questionnaire (GHQ) - 12

    Science.gov (United States)

    2010-01-01

    Background The General Health Questionnaire (GHQ) - 12 was designed as a short questionnaire to assess psychiatric morbidity. Despite the fact that studies have suggested a number of competing multidimensional factor structures, it continues to be largely used as a unidimensional instrument. This may have an impact on the identification of psychiatric morbidity in target populations. The aim of this study was to explore the dimensionality of the GHQ-12 and to evaluate a number of alternative models for the instrument. Methods The data were drawn from a large heterogeneous sample of cancer patients. The Partial Credit Model (Rasch) was applied to the 12-item GHQ. Item misfit (infit mean square ≥ 1.3) was identified, misfitting items removed and unidimensionality and differential item functioning (age, gender, and treatment aims) were assessed. The factor structures of the various alternative models proposed in the literature were explored and optimum model fit evaluated using Confirmatory Factor Analysis. Results The Rasch analysis of the 12-item GHQ identified six misfitting items. Removal of these items produced a six-item instrument which was not unidimensional. The Rasch analysis of an 8-item GHQ demonstrated two unidimensional structures corresponding to Anxiety/Depression and Social Dysfunction. No significant differential item functioning was observed by age, gender and treatment aims for the six- and eight-item GHQ. Two models competed for best fit from the confirmatory factor analysis, namely the GHQ-8 and Hankin's (2008) unidimensional model, however, the GHQ-8 produced the best overall fit statistics. Conclusions The results are consistent with the evidence that the GHQ-12 is a multi-dimensional instrument. Use of the summated scores for the GHQ-12 could potentially lead to an incorrect assessment of patients' psychiatric morbidity. Further evaluation of the GHQ-12 with different target populations is warranted. PMID:20433690

  8. A Rasch and confirmatory factor analysis of the general health questionnaire (GHQ)--12.

    Science.gov (United States)

    Smith, Adam B; Fallowfield, Lesley J; Stark, Dan P; Velikova, Galina; Jenkins, Valerie

    2010-04-30

    The General Health Questionnaire (GHQ) - 12 was designed as a short questionnaire to assess psychiatric morbidity. Despite the fact that studies have suggested a number of competing multidimensional factor structures, it continues to be largely used as a unidimensional instrument. This may have an impact on the identification of psychiatric morbidity in target populations. The aim of this study was to explore the dimensionality of the GHQ-12 and to evaluate a number of alternative models for the instrument. The data were drawn from a large heterogeneous sample of cancer patients. The Partial Credit Model (Rasch) was applied to the 12-item GHQ. Item misfit (infit mean square >or= 1.3) was identified, misfitting items removed and unidimensionality and differential item functioning (age, gender, and treatment aims) were assessed. The factor structures of the various alternative models proposed in the literature were explored and optimum model fit evaluated using Confirmatory Factor Analysis. The Rasch analysis of the 12-item GHQ identified six misfitting items. Removal of these items produced a six-item instrument which was not unidimensional. The Rasch analysis of an 8-item GHQ demonstrated two unidimensional structures corresponding to Anxiety/Depression and Social Dysfunction. No significant differential item functioning was observed by age, gender and treatment aims for the six- and eight-item GHQ. Two models competed for best fit from the confirmatory factor analysis, namely the GHQ-8 and Hankin's (2008) unidimensional model, however, the GHQ-8 produced the best overall fit statistics. The results are consistent with the evidence that the GHQ-12 is a multi-dimensional instrument. Use of the summated scores for the GHQ-12 could potentially lead to an incorrect assessment of patients' psychiatric morbidity. Further evaluation of the GHQ-12 with different target populations is warranted.

  9. Evaluating the Psychometric Properties of the Eating Assessment Tool (EAT-10) Using Rasch Analysis.

    Science.gov (United States)

    Cordier, R; Joosten, A; Clavé, P; Schindler, A; Bülow, M; Demir, N; Arslan, S Serel; Speyer, R

    2017-04-01

    Early and reliable screening for oropharyngeal dysphagia (OD) symptoms in at-risk populations is important and a crucial first stage in effective OD management. The Eating Assessment Tool (EAT-10) is a commonly utilized screening and outcome measure. To date, studies using classic test theory methodologies report good psychometric properties, but the EAT-10 has not been evaluated using item response theory (e.g., Rasch analysis). The aim of this multisite study was to evaluate the internal consistency and structural validity and conduct a preliminary investigation of the cross-cultural validity of the EAT-10; floor and ceiling effects were also checked. Participants involved 636 patients deemed at risk of OD, from outpatient clinics in Spain, Turkey, Sweden, and Italy. The EAT-10 and videofluoroscopic and/or fiberoptic endoscopic evaluation of swallowing were used to confirm OD diagnosis. Patients with esophageal dysphagia were excluded to ensure a homogenous sample. Rasch analysis was used to investigate person and item fit statistics, response scale, dimensionality of the scale, differential item functioning (DIF), and floor and ceiling effect. The results indicate that the EAT-10 has significant weaknesses in structural validity and internal consistency. There are both item redundancy and lack of easy and difficult items. The thresholds of the rating scale categories were disordered and gender, confirmed OD, and language, and comorbid diagnosis showed DIF on a number of items. DIF analysis of language showed preliminary evidence of problems with cross-cultural validation, and the measure showed a clear floor effect. The authors recommend redevelopment of the EAT-10 using Rasch analysis.

  10. Catquest-9SF questionnaire: validation of Malay and Chinese-language versions using Rasch analysis.

    Science.gov (United States)

    Adnan, Tassha Hilda; Mohamed Apandi, Mokhlisoh; Kamaruddin, Haireen; Salowi, Mohamad Aziz; Law, Kian Boon; Haniff, Jamaiyah; Goh, Pik Pin

    2018-01-05

    Catquest questionnaire was originally developed in Swedish to measure patients' self-assessed visual function to evaluate the benefit of cataract surgery. The result of the Rasch analysis leading to the creation of the nine-item short form of Catquest, (Catquest-9SF), and it had been translated and validated in English. The aim is therefore to evaluate the translated Catquest-9SF questionnaire in Malay and Chinese (Mandarin) language version for measuring patient-reported visual function among cataract population in Malaysia. The English version of Catquest-9SF questionnaire was translated and back translated into Malay and Chinese languages. The Malay and Chinese translated versions were self-administered by 236 and 202 pre-operative patients drawn from a cataract surgery waiting list, respectively. The translated Catquest-9SF data and its four response options were assessed for fit to the Rasch model. The Catquest-9SF performed well in the Malay and Chinese translated versions fulfilling all criteria for valid measurement, as demonstrated by Rasch analysis. Both versions of questionnaire had ordered response thresholds, with a good person separation (Malay 2.84; and Chinese 2.59) and patient separation reliability (Malay 0.89; Chinese 0.87). Targeting was 0.30 and -0.11 logits in Malay and Chinese versions respectively, indicating that the item difficulty was well suited to the visual abilities of the patients. All items fit a single overall construct (Malay infit range 0.85-1.26, outfit range 0.73-1.13; Chinese infit range 0.80-1.51, outfit range 0.71-1.36), unidimensional by principal components analysis, and was free of Differential Item Functioning (DIF). These results support the good overall functioning of the Catquest-9SF in patients with cataract. The translated questionnaire to Malay and Chinese-language versions are reliable and valid in measuring visual disability outcomes in the Malaysian cataract population.

  11. Rasch analysis of the Knee injury and Osteoarthritis Outcome Score (KOOS): a statistical re-evaluation

    DEFF Research Database (Denmark)

    Comins, J; Brodersen, J; Krogsgaard, M

    2008-01-01

    The knee injury and Osteoarthritis Outcome Score (KOOS), based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), is widely used to evaluate subjective outcome in anterior cruciate ligament (ACL) reconstructed patients. However, the validity of KOOS has not been assessed...... and subsequent rehabilitation. Rasch analysis showed that of the five proposed subscales in KOOS, only knee-related quality of life (QoL) and sport and recreational related function (Sport/Rec) fulfilled the criteria of a unidimensional measurement scale when applied to these patients. The three subdomains...

  12. Psychometrics evaluation of Charcot-Marie-Tooth Neuropathy Score (CMTNSv2) second version, using Rasch analysis.

    Science.gov (United States)

    Sadjadi, Reza; Reilly, Mary M; Shy, Michael E; Pareyson, Davide; Laura, Matilde; Murphy, Sinead; Feely, Shawna M E; Grider, Tiffany; Bacon, Chelsea; Piscosquito, Giuseppe; Calabrese, Daniela; Burns, Ted M

    2014-09-01

    Charcot-Marie-Tooth Neuropathy Score second version (CMTNSv2) is a validated clinical outcome measure developed for use in clinical trials to monitor disease impairment and progression in affected CMT patients. Currently, all items of CMTNSv2 have identical contribution to the total score. We used Rasch analysis to further explore psychometric properties of CMTNSv2, and in particular, category response functioning, and their weight on the overall disease progression. Weighted category responses represent a more accurate estimate of actual values measuring disease severity and therefore could potentially be used in improving the current version. © 2014 Peripheral Nerve Society.

  13. Higher Education End-of-Course Evaluations: Assessing the Psychometric Properties Utilizing Exploratory Factor Analysis and Rasch Modeling Approaches

    Directory of Open Access Journals (Sweden)

    Kelly D. Bradley

    2016-07-01

    Full Text Available This paper offers a critical assessment of the psychometric properties of a standard higher education end-of-course evaluation. Using both exploratory factor analysis (EFA and Rasch modeling, the authors investigate the (a an overall assessment of dimensionality using EFA, (b a secondary assessment of dimensionality using a principal components analysis (PCA of the residuals when the items are fit to the Rasch model, and (c an assessment of item-level properties using item-level statistics provided when the items are fit to the Rasch model. The results support the usage of the scale as a supplement to high-stakes decision making such as tenure. However, the lack of precise targeting of item difficulty to person ability combined with the low person separation index renders rank-ordering professors according to minuscule differences in overall subscale scores a highly questionable practice.

  14. Clinical usefulness of the clock drawing test applying rasch analysis in predicting of cognitive impairment.

    Science.gov (United States)

    Yoo, Doo Han; Lee, Jae Shin

    2016-07-01

    [Purpose] This study examined the clinical usefulness of the clock drawing test applying Rasch analysis for predicting the level of cognitive impairment. [Subjects and Methods] A total of 187 stroke patients with cognitive impairment were enrolled in this study. The 187 patients were evaluated by the clock drawing test developed through Rasch analysis along with the mini-mental state examination of cognitive evaluation tool. An analysis of the variance was performed to examine the significance of the mini-mental state examination and the clock drawing test according to the general characteristics of the subjects. Receiver operating characteristic analysis was performed to determine the cutoff point for cognitive impairment and to calculate the sensitivity and specificity values. [Results] The results of comparison of the clock drawing test with the mini-mental state showed significant differences in according to gender, age, education, and affected side. A total CDT of 10.5, which was selected as the cutoff point to identify cognitive impairement, showed a sensitivity, specificity, Youden index, positive predictive, and negative predicive values of 86.4%, 91.5%, 0.8, 95%, and 88.2%. [Conclusion] The clock drawing test is believed to be useful in assessments and interventions based on its excellent ability to identify cognitive disorders.

  15. Rasch analysis of the Rosenberg Self-Esteem Scale with African Americans.

    Science.gov (United States)

    Chao, Ruth Chu-Lien; Vidacovich, Courtney; Green, Kathy E

    2017-03-01

    Effectively diagnosing African Americans' self-esteem has posed an unresolved challenge. To address this assessment issue, we conducted exploratory factor analysis and Rasch analysis to assess the psychometric characteristics of the Rosenberg Self-Esteem Scale (RSES, Rosenberg, 1965) for African American college students. The dimensional structure of the RSES was first identified with the first subsample (i.e., calibration subsample) and then held up under cross-validation with a second subsample (i.e., validation subsample). Exploratory factor analysis and Rasch analysis both supported unidimensionality of the measure, with that finding replicated for a random split of the sample. Response scale use was generally appropriate, items were endorsed at a high level reflecting high levels of self-esteem, and person separation and reliability of person separation were adequate, and reflected results similar to those found in prior research. However, as some categories were infrequently used, we also collapsed scale points and found a slight improvement in scale and item indices. No differential item functioning was found by sex or having received professional assistance versus not; there were no mean score differences by age group, marital status, or year in college. Two items were seen as problematic. Implications for theory and research on multicultural mental health are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Organizational Culture Influence On Total Productive Maintenance (TPM and Operational Performance Using RASCH Model Analysis

    Directory of Open Access Journals (Sweden)

    Mohd Norhasni Mohd Asaad

    2014-02-01

    Full Text Available Abstract. Market globalization, competitive product and services, high economic crises are the most critical factors that influence the success of the manufacturing companies in global market. Therefore it is critical to the manufacturing companies to be efficient in production and lean tool may used to achieve that.  The most frequently used is the Total Preventive Maintenance (TPM, even though there are many studies have been conducted in relation to the TPM but there is limited research in investigating the effects of the TPM on operational performance. However, the result of the studies was not consistent, where TPM practice may have positive and negative impact on operational performance. Among the reason is the culture of the organization that influenced the implementation of TPM and operational performance. Due to that this study attempts to investigate the influence of organizational culture on the TPM implementation and operational performance.  Rasch model is used in this study due to its ability in interpreting and analyzing the ability of respondents in performing the difficult items. The online questionnaires were distributed to 63 randomly selected automotive companies located at Northern Region of Malaysia.  Results of the study revealed that the organizational culture has influenced on the successful implementation of TPM and operational performance. Therefore by the implementation of TPM in outstanding organizational culture can improve operational performance.   Keyword: Total Preventive Maintenance (TPM, Lean manufacturing, Operational performance, Organizational culture, Rasch modeldoi:10.12695/ajtm.2013.6.2.2How to cite this article:Mohd Asaad, M.N and Yusoff, R.Z. (2013. Organizational Culture Influence On Total Productive Maintenance (TPM and Operational Performance Using RASCH Model Analysis . The Asian Journal of Technology Management 6 (2: 72-81. Print ISSN: 1978-6956; Online ISSN: 2089-791X.  doi:10.12695/ajtm

  17. Validation of the problem gambling severity index using confirmatory factor analysis and rasch modelling.

    Science.gov (United States)

    Miller, Natalie V; Currie, Shawn R; Hodgins, David C; Casey, David

    2013-09-01

    The Problem Gambling Severity Index (PGSI), a screening tool used to measure the severity of gambling problems in general population research, was subjected to confirmatory factor analysis and Rasch modelling to (a) confirm the one-factor structure; (b) assess how well the items measure the continuum of problem gambling severity; (c) identify sources of differential item functioning among relevant subpopulations of gamblers. Analyses were conducted on a nationally representative sample of over 25,000 gamblers compiled by merging data from the Canadian Community Health Survey and Canadian Problem Gambling Index (CPGI) integrated datasets. Results provided support for a one-factor model that was invariant across gender, age, income level, and gambler type. Rasch modelling revealed a well-fitting, unidimensional model with no miss-fitting items. The average severity assessed by the PGSI is consistent with moderately severe problem gambling. The PGSI is therefore weak in assessing low to moderate problem severity, a notable limitation of most brief gambling screens. Evidence of clinically significant differential item functioning was found with only one item, borrowing money to gamble, which behaved differently in gamblers who play electronic gaming machines or casino games compared to gamblers who avoid these games. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Multidimensional Rasch Analysis of a Psychological Test with Multiple Subtests: A Statistical Solution for the Bandwidth-Fidelity Dilemma

    Science.gov (United States)

    Cheng, Ying-Yao; Wang, Wen-Chung; Ho, Yi-Hui

    2009-01-01

    Educational and psychological tests are often composed of multiple short subtests, each measuring a distinct latent trait. Unfortunately, short subtests suffer from low measurement precision, which makes the bandwidth-fidelity dilemma inevitable. In this study, the authors demonstrate how a multidimensional Rasch analysis can be employed to take…

  19. Further validation of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS) in the UK veterinary profession: Rasch analysis.

    Science.gov (United States)

    Bartram, David J; Sinclair, Julia M; Baldwin, David S

    2013-03-01

    To examine the psychometric properties of the 14-item Warwick-Edinburgh Mental Well-being Scale (WEMWBS) in the UK veterinary profession by the application of Rasch analysis, and to assess the external construct validity of the derived interval scale measurements. Data sets were derived from two independent cross-sectional surveys of the veterinary profession (n = 8,829 and n = 1,796). Rasch analysis (n = 500) included response option thresholds ordering, tests of fit, differential item functioning, targeting, response dependency, and person separation index (PSI). Unidimensionality was evaluated by principal component analysis of residuals. The findings were validated across further subsamples from both data sets. The external construct validity of the Rasch-fitting item set was evaluated by associations with other measures of psychological health or psychosocial work characteristics. Data for the original 14 items deviated significantly from Rasch model expectations (chi-square = 558.2, df = 112, P = scale (Short WEMWBS, SWEMWBS) with acceptable fit to the model (chi-square = 58.8, df = 56, P = 0.104, PSI = 0.832) was derived by sequential removal of the most misfitting items. The external construct validity of SWEMWBS was supported. SWEMWBS has robust interval-level measurement properties which support its suitability as an indicator of population mental health and well-being in this occupational group with elevated suicide risk.

  20. An introduction to Item Response Theory and Rasch Analysis of the Eating Assessment Tool (EAT-10).

    Science.gov (United States)

    Kean, Jacob; Brodke, Darrel S; Biber, Joshua; Gross, Paul

    2018-03-01

    Item response theory has its origins in educational measurement and is now commonly applied in health-related measurement of latent traits, such as function and symptoms. This application is due in large part to gains in the precision of measurement attributable to item response theory and corresponding decreases in response burden, study costs, and study duration. The purpose of this paper is twofold: introduce basic concepts of item response theory and demonstrate this analytic approach in a worked example, a Rasch model (1PL) analysis of the Eating Assessment Tool (EAT-10), a commonly used measure for oropharyngeal dysphagia. The results of the analysis were largely concordant with previous studies of the EAT-10 and illustrate for brain impairment clinicians and researchers how IRT analysis can yield greater precision of measurement.

  1. Rasch Analysis of the Adult Strabismus Quality of Life Questionnaire (AS-20 among Chinese Adult Patients with Strabismus.

    Directory of Open Access Journals (Sweden)

    Zonghua Wang

    Full Text Available The impact of strabismus on visual function, self-image, self-esteem, and social interactions decrease health-related quality of life (HRQoL.The purpose of this study was to evaluate and refine the adult strabismus quality of life questionnaire (AS-20 by using Rasch analysis among Chinese adult patients with strabismus.We evaluated the fitness of the AS-20 with Rasch model in Chinese population by assessing unidimensionality, infit and outfit, person and item separation index and reliability, response ordering, targeting and differential item functioning (DIF.The overall AS-20 did not demonstrate unidimensional; however, it was achieved separately in the two Rasch-revised subscales: the psychosocial subscale (11 items and the function subscale (9 items. The features of good targeting, optimal item infit and outfit, and no notable local dependence were found for each of the subscales. The rating scale was appropriate for the psychosocial subscale but a reduction to four response categories was required for the function subscale. No significant DIF were revealed for any demographic and clinical factors (e.g., age, gender, and strabismus types.The AS-20 was demonstrated by Rasch analysis to be a rigorous instrument for measuring health-related quality of life in Chinese strabismus patents if some revisions were made regarding the subscale construct and response options.

  2. Factor validation and Rasch analysis of the individual recovery outcomes counter.

    Science.gov (United States)

    Dickens, Geoffrey L; Rudd, Bridey; Hallett, Nutmeg; Ion, Robin M; Hardie, Scott M

    2017-09-11

    The individual recovery outcomes counter is a 12-item personal recovery self-assessment tool for adults with mental health problems. Although widely used across Scotland, limited research into its psychometric properties has been conducted. We tested its' measurement properties to ascertain the suitability of the tool for continued use in its' present form. Anonymised data from the assessments of 1743 adults using mental health services in Scotland were subject to tests based on principles of Rasch measurement theory, principal components analysis and confirmatory factor analysis. Rasch analysis revealed that the six-point response structure of the individual recovery outcomes counter (I.ROC) was problematic. Re-scoring on a four-point scale revealed well-ordered items that measure a single, recovery-related construct, and has acceptable fit statistics. Confirmatory factor analysis supported this. Scale items covered around 75% of the recovery continuum; those individuals least far along the continuum were least well addressed. A modified tool worked well for many, but not all, service users. The study suggests specific developments are required if the I.ROC is to maximise its' utility for service users and provide meaningful data for service providers. Implications for Rehabilitation Agencies and services working with people with mental health problems aim to help them with their recovery. The individual recovery outcomes counter has been developed and is used widely in Scotland to help service users track their progress to recovery. Using a large sample of routinely collected data we have demonstrated that a number of modifications are needed if the tool is to adequately measure recovery. This will involve consideration of the scoring system, item content and inclusion, and theoretical basis of the tool.

  3. Assessment of the dimensionality of the Wijma delivery expectancy/experience questionnaire using factor analysis and Rasch analysis.

    Science.gov (United States)

    Pallant, J F; Haines, H M; Green, P; Toohill, J; Gamble, J; Creedy, D K; Fenwick, J

    2016-11-21

    Fear of childbirth has negative consequences for a woman's physical and emotional wellbeing. The most commonly used measurement tool for childbirth fear is the Wijma Delivery Expectancy Questionnaire (WDEQ-A). Although originally conceptualized as unidimensional, subsequent investigations have suggested it is multidimensional. This study aimed to undertake a detailed psychometric assessment of the WDEQ-A; exploring the dimensionality and identifying possible subscales that may have clinical and research utility. WDEQ-A was administered to a sample of 1410 Australian women in mid-pregnancy. The dimensionality of WDEQ-A was explored using exploratory (EFA) and confirmatory factor analysis (CFA), and Rasch analysis. EFA identified a four factor solution. CFA failed to support the unidimensional structure of the original WDEQ-A, but confirmed the four factor solution identified by EFA. Rasch analysis was used to refine the four subscales (Negative emotions: five items; Lack of positive emotions: five items; Social isolation: four items; Moment of birth: three items). Each WDEQ-A Revised subscale showed good fit to the Rasch model and adequate internal consistency reliability. The correlation between Negative emotions and Lack of positive emotions was strong, however Moment of birth and Social isolation showed much lower intercorrelations, suggesting they should not be added to create a total score. This study supports the findings of other investigations that suggest the WDEQ-A is multidimensional and should not be used in its original form. The WDEQ-A Revised may provide researchers with a more refined, psychometrically sound tool to explore the differential impact of aspects of childbirth fear.

  4. A Rasch Analysis of Assessments of Morning and Evening Fatigue in Oncology Patients Using the Lee Fatigue Scale.

    Science.gov (United States)

    Lerdal, Anners; Kottorp, Anders; Gay, Caryl; Aouizerat, Bradley E; Lee, Kathryn A; Miaskowski, Christine

    2016-06-01

    To accurately investigate diurnal variations in fatigue, a measure needs to be psychometrically sound and demonstrate stable item function in relationship to time of day. Rasch analysis is a modern psychometric approach that can be used to evaluate these characteristics. To evaluate, using Rasch analysis, the psychometric properties of the Lee Fatigue Scale (LFS) in a sample of oncology patients. The sample comprised 587 patients (mean age 57.3 ± 11.9 years, 80% women) undergoing chemotherapy for breast, gastrointestinal, gynecological, or lung cancer. Patients completed the 13-item LFS within 30 minutes of awakening (i.e., morning fatigue) and before going to bed (i.e., evening fatigue). Rasch analysis was used to assess validity and reliability. In initial analyses of differential item function, eight of the 13 items functioned differently depending on whether the LFS was completed in the morning or in the evening. Subsequent analyses were conducted separately for the morning and evening fatigue assessments. Nine of the morning fatigue items and 10 of the evening fatigue items demonstrated acceptable goodness-of-fit to the Rasch model. Principal components analyses indicated that both morning and evening assessments demonstrated unidimensionality. Person-separation indices indicated that both morning and evening fatigue scales were able to distinguish four distinct strata of fatigue severity. Excluding four items from the morning fatigue scale and three items from the evening fatigue scale improved the psychometric properties of the LFS for assessing diurnal variations in fatigue severity in oncology patients. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

  5. Patient satisfaction with hospital rehabilitation: validation of the SAT-16 questionnaire through Rasch analysis.

    Science.gov (United States)

    Ottonello, M; Franchignoni, F; Giordano, A; Benevolo, E

    2012-02-01

    The SAT-16 is a 16-item self-administered questionnaire measuring patient satisfaction with the quality of care during stay in a rehabilitation unit. A comprehensive psychometric analysis of SAT-16 was performed using both classical test theory and Rasch analysis (RA) to examine its validity and metric properties, and provide further insights for its clinical use in rehabilitation settings. A sample of 9458 patients, consecutively admitted to two Rehabilitation Centres, was examined with SAT-16. Factor (both explorative and confirmatory) analysis and RA were used to process the data in order to examine validity and metric properties of SAT-16. Dimensionality, item fit to the model, response category performance and internal construct validity were assessed. Two subscales were identified by factor analysis and expert review, respectively related to satisfaction with clinical care (items 1-9), and satisfaction with hospital organization and facilities ("hotel" aspects of care, items 10-16). Each subscale underwent a separate RA. Response categories were revised in both subscales of SAT-16, obtaining a new 3-level rating scale. Both subscales showed high internal consistency and internal validity. RA confirmed the appropriateness of SAT-16 and its usefulness in identifying areas for quality improvement. Overall, the questionnaire allows to assess patient satisfaction with the services through: 1) two sub-scores respectively specific for satisfaction with "clinical care" and "hotel aspects of care"; 2) additional information gathered in the optional open-ended questions.

  6. Linguistic validation of stigmatisation degree, self-esteem and knowledge questionnaire among asthma patients using Rasch analysis.

    Science.gov (United States)

    Ahmad, Sohail; Ismail, Ahmad Izuanuddin; Khan, Tahir Mehmood; Akram, Waqas; Mohd Zim, Mohd Arif; Ismail, Nahlah Elkudssiah

    2017-04-01

    The stigmatisation degree, self-esteem and knowledge either directly or indirectly influence the control and self-management of asthma. To date, there is no valid and reliable instrument that can assess these key issues collectively. The main aim of this study was to test the reliability and validity of the newly devised and translated "Stigmatisation Degree, Self-Esteem and Knowledge Questionnaire" among adult asthma patients using the Rasch measurement model. This cross-sectional study recruited thirty adult asthma patients from two respiratory specialist clinics in Selangor, Malaysia. The newly devised self-administered questionnaire was adapted from relevant publications and translated into the Malay language using international standard translation guidelines. Content and face validation was done. The data were extracted and analysed for real item reliability and construct validation using the Rasch model. The translated "Stigmatisation Degree, Self-Esteem and Knowledge Questionnaire" showed high real item reliability values of 0.90, 0.86 and 0.89 for stigmatisation degree, self-esteem, and knowledge of asthma, respectively. Furthermore, all values of point measure correlation (PTMEA Corr) analysis were within the acceptable specified range of the Rasch model. Infit/outfit mean square values and Z standard (ZSTD) values of each item verified the construct validity and suggested retaining all the items in the questionnaire. The reliability analyses and output tables of item measures for construct validation proved the translated Malaysian version of "Stigmatisation Degree, Self-Esteem and Knowledge Questionnaire" as a valid and highly reliable questionnaire.

  7. Rasch Model Analysis Gives New Insights Into the Structural Validity of the QuickDASH in Patients With Musculoskeletal Shoulder Pain.

    Science.gov (United States)

    Jerosch-Herold, Christina; Chester, Rachel; Shepstone, Lee

    2017-09-01

    Study Design Cross-sectional secondary analysis of a prospective cohort study. Background The shortened version of the Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) is a widely used outcome measure that has been extensively evaluated using classical test theory. Rasch model analysis can identify strengths and weaknesses of rating scales and goes beyond classical test theory approaches. It uses a mathematical model to test the fit between the observed data and expected responses and converts ordinal-level scores into interval-level measurement. Objective To test the structural validity of the QuickDASH using Rasch analysis. Methods A prospective cohort study of 1030 patients with shoulder pain provided baseline data. Rasch analysis was conducted to (1) assess how the QuickDASH fits the Rasch model, (2) identify sources of misfit, and (3) explore potential solutions to these. Results There was evidence of multidimensionality and significant misfit to the Rasch model (χ 2 = 331.09, PSports Phys Ther 2017;47(9):664-672. Epub 13 Jul 2017. doi:10.2519/jospt.2017.7288.

  8. Psychometric Properties of the PsychoSomatic Problems Scale: A Rasch Analysis on Adolescent Data

    Science.gov (United States)

    Hagquist, Curt

    2008-01-01

    The PsychoSomatic Problems (PSP)-scale is built upon eight items intended to tap information about psychosomatic problems among schoolchildren and adolescents in general populations. The purpose of the study is to analyse the psychometric properties of the PSP-scale by means of the Rasch model, with a focus on the operating characteristics of the…

  9. Using Hospital Anxiety and Depression Scale (HADS) on patients with epilepsy: Confirmatory factor analysis and Rasch models.

    Science.gov (United States)

    Lin, Chung-Ying; Pakpour, Amir H

    2017-02-01

    The problems of mood disorders are critical in people with epilepsy. Therefore, there is a need to validate a useful tool for the population. The Hospital Anxiety and Depression Scale (HADS) has been used on the population, and showed that it is a satisfactory screening tool. However, more evidence on its construct validity is needed. A total of 1041 people with epilepsy were recruited in this study, and each completed the HADS. Confirmatory factor analysis (CFA) and Rasch analysis were used to understand the construct validity of the HADS. In addition, internal consistency was tested using Cronbachs' α, person separation reliability, and item separation reliability. Ordering of the response descriptors and the differential item functioning (DIF) were examined using the Rasch models. The HADS showed that 55.3% of our participants had anxiety; 56.0% had depression based on its cutoffs. CFA and Rasch analyses both showed the satisfactory construct validity of the HADS; the internal consistency was also acceptable (α=0.82 in anxiety and 0.79 in depression; person separation reliability=0.82 in anxiety and 0.73 in depression; item separation reliability=0.98 in anxiety and 0.91 in depression). The difficulties of the four-point Likert scale used in the HADS were monotonically increased, which indicates no disordering response categories. No DIF items across male and female patients and across types of epilepsy were displayed in the HADS. The HADS has promising psychometric properties on construct validity in people with epilepsy. Moreover, the additive item score is supported for calculating the cutoff. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  10. Can rasch analysis enhance the abstract ranking process in scientific conferences? Issues of interrater variability and abstract rating burden.

    Science.gov (United States)

    Scanlan, Justin Newton; Lannin, Natasha A; Hoffmann, Tammy

    2015-01-01

    Abstract ranking processes for scientific conferences are essential but controversial. This study examined the validity of a structured abstract rating instrument, evaluated interrater variability, and modeled the impact of interrater variability on abstract ranking decisions. Additionally, we examined whether a more efficient rating process (abstracts rated by two rather than three raters) supported valid abstract rankings. Data were 4016 sets of abstract ratings from the 2011 and 2013 national scientific conferences for a health discipline. Many-faceted Rasch analysis procedures were used to examine validity of the abstract rating instrument and to identify and adjust for the presence of interrater variability. The two-rater simulation was created by the deletion of one set of ratings for each abstract in the 2013 data set. The abstract rating instrument demonstrated sound measurement properties. Although each rater applied the rating criteria consistently (intrarater reliability), there was significant variability between raters. Adjusting for interrater variability changed the final presentation format for approximately 10-20% of abstracts. The two-rater simulation demonstrated that abstract rankings derived through this process were valid, although the impact of interrater variability was more substantial. Interrater variability exerts a small but important influence on overall abstract acceptance outcome. The use of many-faceted Rasch analysis allows for this variability to be adjusted for. Additionally, Rasch processes allow for more efficient abstract ranking by reducing the need for multiple raters. © 2015 The Alliance for Continuing Education in the Health Professions, the Society for Academic Continuing Medical Education, and the Council on Continuing Medical Education, Association for Hospital Medical Education.

  11. Exploring the construct validity of the Patient Perception Measure - Osteopathy (PPM-O) using classical test theory and Rasch analysis.

    Science.gov (United States)

    Mulcahy, Jane; Vaughan, Brett

    2015-01-01

    Evaluation of patients' experience of their osteopathic treatment has recently been investigated leading to the development of the Patient Perception Measure - Osteopathy (PPM-O). The aim of the study was to investigate the construct validity of the PPM-O. Patients presenting to osteopathy student-led teaching clinics at two Australian universities were asked to complete two questionnaires after their treatment: a demographic questionnaire and the PPM-O. Confirmatory factor analysis (CFA) and Rasch analysis were used to investigate the construct validity of the PPM-O. Data from the present study did not fit the a-priori 6-domain structure in the CFA. Modifications to the 6-domain model were then made based on the CFA results, and this analysis identified two factors: 1) Education & Information (9 items); and 2) Cognition & Fatigue (6 items). These two factors were Rasch analysed individually. Two items were removed from the Cognition & Fatigue factor during the analysis. The two factors independently were unidimensional. The study produced a 2-factor, 13-item questionnaire that assesses the patients' perception of their osteopathic treatment using the items from a previous questionnaire. The results of the current study provide evidence for the construct validity of the PPM-O and the small number of items makes it feasible to implement into both clinical and research settings. Further research is now required to establish the measures' validity in a variety of patient populations.

  12. USING RASCH ANALYSIS TO EXPLORE WHAT STUDENTS LEARN ABOUT PROBABILITY CONCEPTS

    Directory of Open Access Journals (Sweden)

    Zamalia Mahmud

    2015-01-01

    Full Text Available Students’ understanding of probability concepts have been investigated from various different perspectives. This study was set out to investigate perceived understanding of probability concepts of forty-four students from the STAT131 Understanding Uncertainty and Variation course at the University of Wollongong, NSW. Rasch measurement which is based on a probabilistic model was used to identify concepts that students find easy, moderate and difficult to understand. Data were captured from the e-learning Moodle platform where students provided their responses through an on-line quiz. As illustrated in the Rasch map, 96% of the students could understand about sample space, simple events, mutually exclusive events and tree diagram while 67% of the students found concepts of conditional and independent events rather easy to understand

  13. The "Spirit 8" successfully captured spiritual well-being in African palliative care: factor and Rasch analysis.

    Science.gov (United States)

    Selman, Lucy; Siegert, Richard J; Higginson, Irene J; Agupio, Godfrey; Dinat, Natalya; Downing, Julia; Gwyther, Liz; Mashao, Thandi; Mmoledi, Keletso; Moll, Tony; Sebuyira, Lydia Mpanga; Ikin, Barbara; Harding, Richard

    2012-04-01

    To describe the dimensionality of a measure of spiritual well-being (SWB) (the "Spirit 8") in palliative care (PC) patients in South Africa and Uganda, and to determine SWB in this population. A cross-sectional survey was conducted using the Missoula Vitas Quality of Life Index (MVQOLI). Translated questionnaires were administered to consecutively recruited patients. Factor analysis and Rasch analysis were used to examine the dimensionality of eight items from the Well-being and Transcendent subscales. The resulting measure (the "Spirit 8") was used to determine levels of SWB. Two hundred eighty-five patients recruited; mean age 40.1; 197 (69.1%) female; primary diagnosis HIV (80.7%), cancer (17.9%). Internal consistency of the eight-item scale was α=0.73; Well-being factor α=0.69, Transcendence factor α=0.68. Rasch analysis suggested unidimensionality. Mean SWB score was 26.01 (standard deviation 5.68). Spiritual distress was present in 21.4-57.9%. Attending the Ugandan service, HIV and younger age were associated with poorer SWB scores. The Spirit 8 is a brief, psychometrically robust, unidimensional measure of SWB for use in South African and Ugandan PC research. Further research testing the Spirit 8 and examining the SWB of PC patients in South Africa and Uganda is needed to improve spiritual care. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Psychometric properties of the Zarit Caregiver Burden Interview administered to caregivers to patients with Duchenne muscular dystrophy: a Rasch analysis.

    Science.gov (United States)

    Landfeldt, Erik; Mayhew, Anna; Straub, Volker; Bushby, Katharine; Lochmüller, Hanns; Lindgren, Peter

    2017-12-18

    To explore the psychometric properties of the full 22-item English (UK and US) version of the Zarit Caregiver Burden Interview administered to caregivers to patients with Duchenne muscular dystrophy. Caregivers to patients with Duchenne muscular dystrophy from the United Kingdom and the United States, recruited through the TREAT-NMD network, completed the Zarit Caregiver Burden Interview online. The psychometric properties of the Zarit Caregiver Burden Interview were examined using Rasch analysis. A total of 475 caregivers completed the Zarit Caregiver Burden Interview. Model misfit was identified for 9 of 22 items (mean item fit residual 0.061, SD: 2.736) and 13 of 22 items displayed disordered thresholds. The overall item-trait interaction chi-square value was 499 (198 degrees of freedom, p Duchenne muscular dystrophy from the United Kingdom and the United States. Further research is needed to understand the psychometric properties of the Zarit Caregiver Burden Interview in other populations and settings. Implications for Rehabilitation Duchenne muscular dystrophy is a terminal disease characterized by progressive muscle degeneration resulting in substantial disability and a significant burden on family caregivers. The Zarit Caregiver Burden Interview is one of the most widely applied measures of caregiver burden. Our Rasch analysis suggests that the Zarit Caregiver Burden Interview is not fit for purpose to measure burden in UK and US caregivers to patients with Duchenne muscular dystrophy. Clinicians and decision-makers should interpret Zarit Caregiver Burden Interview data from these populations with caution.

  15. Rasch Analysis of a New Hierarchical Scoring System for Evaluating Hand Function on the Motor Assessment Scale for Stroke

    Directory of Open Access Journals (Sweden)

    Joyce S. Sabari

    2014-01-01

    Full Text Available Objectives. (1 To develop two independent measurement scales for use as items assessing hand movements and hand activities within the Motor Assessment Scale (MAS, an existing instrument used for clinical assessment of motor performance in stroke survivors; (2 To examine the psychometric properties of these new measurement scales. Design. Scale development, followed by a multicenter observational study. Setting. Inpatient and outpatient occupational therapy programs in eight hospital and rehabilitation facilities in the United States and Canada. Participants. Patients (N=332 receiving stroke rehabilitation following left (52% or right (48% cerebrovascular accident; mean age 64.2 years (sd 15; median 1 month since stroke onset. Intervention. Not applicable. Main Outcome Measures. Data were tested for unidimensionality and reliability, and behavioral criteria were ordered according to difficulty level with Rasch analysis. Results. The new scales assessing hand movements and hand activities met Rasch expectations of unidimensionality and reliability. Conclusion. Following a multistep process of test development, analysis, and refinement, we have redesigned the two scales that comprise the hand function items on the MAS. The hand movement scale contains an empirically validated 10-behavior hierarchy and the hand activities item contains an empirically validated 8-behavior hierarchy.

  16. A Rasch analysis of patients' opinions of primary health care professionals' ethical behaviour with respect to communication issues.

    Science.gov (United States)

    González-de Paz, Luis; Kostov, Belchin; López-Pina, Jose A; Solans-Julián, Pilar; Navarro-Rubio, M Dolors; Sisó-Almirall, Antoni

    2015-04-01

    Patients' opinions are crucial in assessing the effectiveness of the ethical theories which underlie the care relationship between patients and primary health care professionals. To study the ethical behaviour of primary health care professionals with respect to communication issues according to patients' opinions. Cross-sectional study using a self-administered questionnaire in patients from a network of 15 urban primary health centres. Participants were patients attended at the centres when the study was conducted. We used a Rasch analysis to verify the structure of the 17 questionnaire items, and to calculate interval level measures for patients and items. We analysed differences according to patient subgroups using analysis of variance tests and differences between the endorsement of each item. We analysed 1013 (70.34%) of questionnaires. Data fit to the Rasch model was achieved after collapsing two categories and eliminating five items. Items with the lowest degree of endorsement were related to the management of differences in conflictive situations between patients and health care professionals. We found significant differences (P communication skills were respected by family physicians and nurses. However, opinions on endorsement were lower when patients disagreed with health care professionals. The differences found between patient subgroups demonstrated the importance of trust and confidence between patients and professionals. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Psychometric properties of scale constructed from the International Classification of Functioning, Disability and Health (ICF) core set for breast cancer based on Rasch analysis.

    Science.gov (United States)

    Yang, Eun Joo; Shin, Eun-Kyoung; Shin, Hyung-Ik; Lim, Jae-Young

    2014-10-01

    The purpose of this study was to construct a clinical instrument to measure functioning in breast cancer survivors using the International Classification of Functioning, Disability and Health (ICF) categories for body functions, activity and participation, and environmental factors, based on a Rasch analysis. Items were generated from the brief ICF core set for breast cancer and in-depth interviews from eight oncologists. Psychometric properties were evaluated in 158 female Korean patients with breast cancer using Rasch analysis, such as fit of the ICF categories, targeting between the ICF categories and a person's abilities, unidimensionality, and reliability. The Rasch refinement led to a change from the original 43-item, 5-level scale to a 30-item, 3- or 4-level scale. Rasch reliabilities were 0.89 (body function scale), 0.96 (activity and participation scale), and 0.93 (environmental scale). The item-difficulty hierarchy was stable across age (Breast Cancer Questionnaire for Screening is a reliable and valid 30-item questionnaire based on the brief ICF core set. It allows measurement of functioning as a unidimensional construct in patients with breast cancer.

  18. Achieving stringent climate targets. An analysis of the role of transport and variable renewable energies using energy-economy-climate models

    Energy Technology Data Exchange (ETDEWEB)

    Pietzcker, Robert Carl

    2014-07-01

    Anthropogenic climate change is threatening the welfare of mankind. Accordingly, policy makers have repeatedly stated the goal of slowing climate change and limiting the increase of global mean temperature to less than 2 C above pre-industrial times (the so-called ''two degree target''). Stabilizing the temperature requires drastic reductions of greenhouse gas (GHG) emissions to nearly zero. As the global system of energy supply currently relies on fossil fuels, reducing GHG emissions can only be achieved through a full-scale transformation of the energy system. This thesis investigates the economic requirements and implications of different scenarios that achieve stringent climate mitigation targets. It starts with the analysis of characteristic decarbonization patterns and identifies two particularly relevant aspects of mitigation scenarios: deployment of variable renewable energies (VRE) and decarbonization of the transport sector. After investigating these fields in detail, we turned towards one of the most relevant questions for policy makers and analyzed the trade-off between the stringency of a climate target and its economic requirements and implications. All analyses are based on the improvement, application, comparison, and discussion of large-scale IAMs. The novel ''mitigation share'' metric allowed us to identify the relevance of specific technology groups for mitigation and to improve our understanding of the decarbonization patterns of different energy subsectors. It turned out that the power sector is decarbonized first and reaches lowest emissions, while the transport sector is slowest to decarbonize. For the power sector, non-biomass renewable energies contribute most to emission reductions, while the transport sector strongly relies on liquid fuels and therefore requires biomass in combination with carbon capture and sequestration (CCS) to reduce emissions. An in-depth investigation of the solar power

  19. Mini-Mental Status Examination: mixed Rasch model item analysis derived two different cognitive dimensions of the MMSE

    DEFF Research Database (Denmark)

    Schultz-Larsen, Kirsten; Kreiner, Svend; Lomholt, Rikke Kirstine

    2006-01-01

    OBJECTIVES: This study published in two companion papers assesses properties of the Mini-Mental State Examination (MMSE) with the purpose of improving the efficiencies of the methods of screening for cognitive impairment and dementia. STUDY DESIGN AND SETTING: An item analysis by conventional...... and mixed Rasch models was used to explore empirically derived cognitive dimensions of the MMSE, to assess item bias, and to construct diagnostic cut-points. The scores of 1,189 elderly residents were analyzed. RESULTS: Two dimensions of cognitive function, which are statistically and conceptually different......, registration, recall, reading, and copying). The "writing" item was not included due to differential effects of age and sex. The analysis also showed that the study sample consisted of two cognitively different groups of elderly. CONCLUSIONS: The findings indicate that a two-scale solution is a stable...

  20. Teachers' Checklist on Reading-Related Behavioral Characteristics of Chinese Primary Students: A Rasch Measurement Model Analysis

    Science.gov (United States)

    Chan, David W.; Ho, Connie Suk-han; Chung, Kevin K. H.; Tsang, Suk-man; Lee, Suk-han

    2010-01-01

    Data of item responses to the Hong Kong Specific Learning Difficulties Behaviour Checklist from 673 Chinese primary grade students were analyzed using the dichotomous Rasch measurement model. Rasch scaling suggested that the data fit the model adequately with a latent dimension of global dyslexic dysfunctioning. Estimates of item attributes and…

  1. Measuring teacher dispositions using the DAATS battery: a multifaceted Rasch analysis of rater effect.

    Science.gov (United States)

    Lang, W Steve; Wilkerson, Judy R; Rea, Dorothy C; Quinn, David; Batchelder, Heather L; Englehart, Dierdre S; Jennings, Kelly J

    2014-01-01

    The purpose of this study was to examine the extent to which raters' subjectivity impacts measures of teacher dispositions using the Dispositions Assessments Aligned with Teacher Standards (DAATS) battery. This is an important component of the collection of evidence of validity and reliability of inferences made using the scale. It also provides needed support for the use of subjective affective measures in teacher training and other professional preparation programs, since these measures are often feared to be unreliable because of rater effect. It demonstrates the advantages of using the Multi-Faceted Rasch Model as a better alternative to the typical methods used in preparation programs, such as Cohen's Kappa. DAATS instruments require subjective scoring using a six-point rating scale derived from the affective taxonomy as defined by Krathwohl, Bloom, and Masia (1956). Rater effect is a serious challenge and can worsen or drift over time. Errors in rater judgment can impact the accuracy of ratings, and these effects are common, but can be lessened through training of raters and monitoring of their efforts. This effort uses the multifaceted Rasch measurement models (MFRM) to detect and understand the nature of these effects.

  2. The nutrition for sport knowledge questionnaire (NSKQ): development and validation using classical test theory and Rasch analysis.

    Science.gov (United States)

    Trakman, Gina Louise; Forsyth, Adrienne; Hoye, Russell; Belski, Regina

    2017-01-01

    Appropriate dietary intake can have a significant influence on athletic performance. There is a growing consensus on sports nutrition and professionals working with athletes often provide dietary education. However, due to the limitations of existing sports nutrition knowledge questionnaires, previous reports of athletes' nutrition knowledge may be inaccurate. An updated questionnaire has been developed based on a recent review of sports nutrition guidelines. The tool has been validated using a robust methodology that incorporates relevant techniques from classical test theory (CTT) and Item response theory (IRT), namely, Rasch analysis. The final questionnaire has 89 questions and six sub-sections (weight management, macronutrients, micronutrients, sports nutrition, supplements, and alcohol). The content and face validity of the tool have been confirmed based on feedback from expert sports dietitians and university sports students, respectively. The internal reliability of the questionnaire as a whole is high (KR = 0.88), and most sub-sections achieved an acceptable internal reliability. Construct validity has been confirmed, with an independent T-test revealing a significant ( p  < 0.001) difference in knowledge scores of nutrition (64 ± 16%) and non-nutrition students (51 ± 19%). Test-retest reliability has been assured, with a strong correlation ( r  = 0.92, p  < 0.001) between individuals' scores on two attempts of the test, 10 days to 2 weeks apart. Three of the sub-sections fit the Rasch Unidimensional Model. The final version of the questionnaire represents a significant improvement over previous tools. Each nutrition sub-section is unidimensional, and therefore researchers and practitioners can use these individually, as required. Use of the questionnaire will allow researchers to draw conclusions about the effectiveness of nutrition education programs, and differences in knowledge across athletes of varying ages, genders, and athletic

  3. Rasch analysis of the WHOQOL-BREF in post polio syndrome.

    Science.gov (United States)

    Pomeroy, Ian M; Tennant, Alan; Young, Carolyn A

    2013-09-01

    The World Health Organisation quality of life abbreviated scale (WHOQOL-BREF) was developed as a measure of quality of life across 4 separate health domains; physical health, psychological, social relationships and environment. This study evaluated the validity of the WHOQOL-BREF in post-polio syndrome by testing it for fit against the Rasch model. The scale was posted to 319 volunteers, 271 (85%) completed the scale with a mean age of 66.7 years (standard deviation 8.15); 64% were female. The social relationships domain fitted the Rasch model (χ2 p = 0.19) but reliability was low (α = 0.69) and there were insufficient items to test the assumption of unidimensionality. Solutions were derived for physical health (p = 0.45, t-test = 1.5%, α = 0.67), psychological (p = 0.19, t-test = 4.9%, α = 0.78) and environment domains (p = 0.48, t-test = 6.0% - lower confidence interval 3.4%, α = 0.80) by accounting for local dependence and to cancel out differential item functioning. An overall measure of quality of life, which combined all 4 domains was validated (p = 0.80, t-test = 4.6%, α = 0.81). A transformation table for this total score is provided. The 4 domains of the WHOQOL-BREF provide valid measures of quality of life in post-polio syndrome. The summed score was more reliable and better targeted and can be used as an ordinal estimate of quality of life.

  4. Loglinear Rasch model tests

    NARCIS (Netherlands)

    Kelderman, Hendrikus

    1984-01-01

    Existing statistical tests for the fit of the Rasch model have been criticized, because they are only sensitive to specific violations of its assumptions. Contingency table methods using loglinear models have been used to test various psychometric models. In this paper, the assumptions of the Rasch

  5. Does the Brief-BESTest Meet Classical Test Theory and Rasch Analysis Requirements for Balance Assessment in People With Neurological Disorders?

    Science.gov (United States)

    Bravini, Elisabetta; Nardone, Antonio; Godi, Marco; Guglielmetti, Simone; Franchignoni, Franco; Giordano, Andrea

    2016-10-01

    The Brief Balance Evaluation Systems Test (Brief-BESTest) was recently proposed as a clinical tool for quickly measuring balance disorders, but its measurement properties warrant investigation. The study objective was to perform a detailed analysis of the psychometric properties of the Brief-BESTest by means of Classical Test Theory and Rasch analysis. This was an observational measurement study. Brief-BESTest data were collected from a sample of 244 participants. Internal consistency was analyzed with the Cronbach α and item-to-total correlations. Test-retest reliability and interrater reliability were investigated in a subgroup of 21 participants. The minimum detectable change at the 95% confidence level was calculated. Scale dimensionality was examined through Horn parallel analysis; this step was followed by exploratory factor analysis for ordinal data. Finally, data were examined using Rasch analysis (rating scale model). The Cronbach α was .89, and all item-to-total correlations were greater than .40. Test-retest reliability had an intraclass correlation coefficient (ICC) (2,1) of .94, and interrater reliability had an ICC (2,1) of .90. The minimum detectable change at the 95% confidence level was 4.30 points. The unidimensionality of the test was confirmed, but 1 item showed low communality. Rasch analysis revealed the inadequacy of response categories, 5 misfitting items, minor mistargeting, moderate person reliability (.80), and 2 pairs of locally dependent items. The sample was a cross-section of people who had balance disorders from different neurological etiologies and were recruited consecutively at a single rehabilitation facility. The Brief-BESTest was confirmed to have some acceptable-to-good reliability indexes when calculated according to Classical Test Theory, but the scale showed fairly limited sensitivity to change. Rasch analysis indicated that item selection should be improved from a psychometric point of view. Item redundancy needs to be

  6. Unified Balance Scale: an activity-based, bed to community, and aetiology-independent measure of balance calibrated with Rasch analysis.

    Science.gov (United States)

    La Porta, Fabio; Franceschini, Marco; Caselli, Serena; Cavallini, Paola; Susassi, Sonia; Tennant, Alan

    2011-04-01

    To build a new activity-based, "bed to community", aetiology-independent measure of balance within the neurological rehabilitation setting by merging some existing scales. Balance scales were selected using a conceptual framework and subsequently administered to a convenience sample of adult patients with balance problems due to different neurological aetiologies. Data were then processed using classical psychometric analyses and Rasch analysis in order to construct a new balance measurement tool. The Berg Balance Scale, the Tinetti Scales and the Fullerton Advanced Balance Scale were selected and administered to a sample of patients, giving 302 observations. Classical psychometric analyses (item and scale analysis; confirmatory factor analysis) were undertaken on the pooled 40-item set with confirmation of unidimensionality. The subsequent Rasch analysis allowed the identification of a 27-item set satisfying the Rasch Model's requirements for fundamental measurement, with further confirmation of unidimensionality by post-hoc confirmatory factor analysis. The new scale (Unified Balance Scale) holds proven measurement properties and may be a candidate tool for "bed to community" balance measurement for patients with balance problems within the neuro-rehabilitation setting. Future studies are warranted to explore further its external validity and other clinical properties, as well as to improve its usability.

  7. Brazilian WHOQOL-OLD Module version: a Rasch analysis of a new instrument Versão em português do Módulo WHOQOL-OLD: análise de Rasch de um novo instrumento

    Directory of Open Access Journals (Sweden)

    Eduardo Chachamovich

    2008-04-01

    Full Text Available OBJECTIVE: To evaluate the Brazilian version of WHOQOL-OLD Module and to test potential changes to the instrument to increase its psychometric adequacy. METHODS: A total of 424 older adults living in a city in Southern Brazil completed the WHOQOL-OLD instrument, in 2005. Rasch analysis was used to explore the psychometric performance of the scale, as implemented by the RUMM2020 software. Item-trait interaction, threshold disorders, presence of differential item functioning and item fit, were analyzed. RESULTS: Two ("death and dying" and "sensory abilities" out of six domains showed inadequate item-trait interactions. Rescoring the response scale and deleting the most misperforming items led to scale improvement. The evaluation of domains and items individually showed that the "intimacy" domain does perform well in contrast to the findings using the classical approach. In addition, the "sensory abilities" domain does not derive an interval measure in its current format. CONCLUSIONS: Unidimensionality and local independence were seen in all domains. Changes in the response scale and deletion of problematic items improved the scale's performance.OBJETIVO: Analisar a versão brasileira do Módulo WHOQOL-OLD, indicando alterações potenciais do instrumento para aumentar a adequação psicométrica. MÉTODOS: O total de 424 idosos residentes em Porto Alegre, RS, responderam o instrumento WHOQOL-OLD em 2005. O modelo de Rasch foi utilizado para a análise do desempenho psicométrico da escala, a partir do software RUMM2020. Foram analisadas a interação item-traço, a presença de funcionamento diferencial dos itens e a adequação dos itens ao modelo de Rasch. RESULTADOS: Dois domínios ("morte e morrer" e "funcionamento do sensório" apresentaram interação item-total insuficiente. Remodelar a escala de resposta e excluir itens com pior performance resultou em melhora da escala. A análise dos domínios e itens individualmente foi capaz de indicar

  8. Analysis of the psychometric properties of the American Orthopaedic Foot and Ankle Society Score (AOFAS) in rheumatoid arthritis patients: application of the Rasch model.

    Science.gov (United States)

    Conceição, Cristiano Sena da; Neto, Mansueto Gomes; Neto, Anolino Costa; Mendes, Selena M D; Baptista, Abrahão Fontes; Sá, Kátia Nunes

    2016-01-01

    To tested the reliability and validity of Aofas in a sample of rheumatoid arthritis patients. The scale was applicable to rheumatoid arthritis patients, twice by the interviewer 1 and once by the interviewer 2. The Aofas was subjected to test-retest reliability analysis (with 20 Rheumatoid arthritis subjects). The psychometric properties were investigated using Rasch analysis on 33 Rheumatoid arthritis patients. Intra-Class Correlation Coefficient (ICC) were (0.90Rasch analysis showed that eight items was satisfactory. One erroneous item have been identified, showing percentages above the 5% allowed by the statistical model. Further Rasch modeling suggested revising the original item 8. The results suggest that the Brazilian versions of Aofas exhibit adequate reliability, construct validity, response stability. These findings indicate that Aofas Ankle-Hindfoot scale presents a significant potential for clinical applicability in individuals with rheumatoid arthritis. Other studies in populations with other characteristics are now underway. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

  9. Construct validity of the Heart Failure Screening Tool (Heart-FaST) to identify heart failure patients at risk of poor self-care: Rasch analysis.

    Science.gov (United States)

    Reynolds, Nicholas A; Ski, Chantal F; McEvedy, Samantha M; Thompson, David R; Cameron, Jan

    2018-02-14

    The aim of this study was to psychometrically evaluate the Heart Failure Screening Tool (Heart-FaST) via: (1) examination of internal construct validity; (2) testing of scale function in accordance with design; and (3) recommendation for change/s, if items are not well adjusted, to improve psychometric credential. Self-care is vital to the management of heart failure. The Heart-FaST may provide a prospective assessment of risk, regarding the likelihood that patients with heart failure will engage in self-care. Psychometric validation of the Heart-FaST using Rasch analysis. The Heart-FaST was administered to 135 patients (median age = 68, IQR = 59-78 years; 105 males) enrolled in a multidisciplinary heart failure management program. The Heart-FaST is a nurse-administered tool for screening patients with HF at risk of poor self-care. A Rasch analysis of responses was conducted which tested data against Rasch model expectations, including whether items serve as unbiased, non-redundant indicators of risk and measure a single construct and that rating scales operate as intended. The results showed that data met Rasch model expectations after rescoring or deleting items due to poor discrimination, disordered thresholds, differential item functioning, or response dependence. There was no evidence of multidimensionality which supports the use of total scores from Heart-FaST as indicators of risk. Aggregate scores from this modified screening tool rank heart failure patients according to their "risk of poor self-care" demonstrating that the Heart-FaST items constitute a meaningful scale to identify heart failure patients at risk of poor engagement in heart failure self-care. © 2018 John Wiley & Sons Ltd.

  10. Physics Metacognition Inventory Part Ii: Confirmatory Factor Analysis and Rasch Analysis

    Science.gov (United States)

    Taasoobshirazi, Gita; Bailey, MarLynn; Farley, John

    2015-01-01

    The Physics Metacognition Inventory was developed to measure physics students' metacognition for problem solving. In one of our earlier studies, an exploratory factor analysis provided evidence of preliminary construct validity, revealing six components of students' metacognition when solving physics problems including knowledge of cognition,…

  11. Improving Measurement of Trait Competitiveness: A Rasch Analysis of the Revised Competitiveness Index With Samples From New Zealand and US University Students.

    Science.gov (United States)

    Krägeloh, Christian U; Medvedev, Oleg N; Hill, Erin M; Webster, Craig S; Booth, Roger J; Henning, Marcus A

    2018-01-01

    Measuring competitiveness is necessary to fully understand variables affecting student learning. The 14-item Revised Competitiveness Index has become a widely used measure to assess trait competitiveness. The current study reports on a Rasch analysis to investigate the psychometric properties of the Revised Competitiveness Index and to improve its precision for international comparisons. Students were recruited from medical studies at a university in New Zealand, undergraduate health sciences courses at another New Zealand university, and a psychology undergraduate class at a university in the United States. Rasch model estimate parameters were affected by local dependency and item misfit. Best fit to the Rasch model (χ 2 (20) = 15.86, p = .73, person separation index = .95) was obtained for the Enjoyment of Competition subscale after combining locally dependent items into a subtest and discarding the highly misfitting Item 9. The only modifications required to obtain a suitable fit (χ 2 (25) = 25.81, p = .42, person separation index = .77) for the Contentiousness subscale were a subtest to combine two locally dependent items and splitting this subtest by country to deal with differential item functioning. The results support reliability and internal construct validity of the modified Revised Competitiveness Index. Precision of the measure may be enhanced using the ordinal-to-interval conversion algorithms presented here, allowing the use of parametric statistics without breaking fundamental statistical assumptions.

  12. Psychometric properties of the Oswestry disability index: Rasch analysis of responses in a work-disabled population.

    Science.gov (United States)

    Lochhead, Lois E; MacMillan, Peter D

    2013-01-01

    The Oswestry disability index (ODI) is the most widely used measure of perceived disability for low back conditions. It has been adopted without adaptation in functional capacity evaluation (FCE). Rigorous testing of the ODI with modern psychometric methods, in this setting, is warranted. To determine the psychometric properties of the ODI in FCE: unidimensionality; differential item functioning; item coverage and to identify poorly functioning items, allowing for improvement of these items and recalibration of the scale. Rasch analysis, specifically Masters' partial credit model, was conducted on data. 133 work-disabled individuals presenting for FCE in northern British Columbia, Canada. All items had one poorly functioning option. Items were rescaled from six categories to five, improving the psychometric properties of the ODI as a unidimensional (disability due to back pain) scale. Item difficulty range is sufficient for a population with mild to severe disability. Although two of the ten ODI items functioned marginally unsatisfactorily in the unrevised state, the 5-option revised ODI appears superior. Use in clinical settings across a broad spectrum of disability levels could help establish its psychometric properties. Health professionals should be aware that the ODI may perform differently depending on client population.

  13. Rasch analysis of the Spanish version of the Mindful Attention Awareness Scale (MAAS) in a clinical sample.

    Science.gov (United States)

    Inchausti, Felix; Prieto, Gerardo; Delgado, Ana R

    2014-01-01

    The clinical use of mindfulness has increased recently, and the Mindful Attention Awareness Scale (MAAS) has become one of the most used tools to measure it. The aim of this study was to test the effectiveness of mindfulness training and analyzing the psychometric properties of the MAAS scores in a clinical sample using the Rasch Model. One hundred and ninety-nine participants with mood-anxiety clinical symptoms were recruited. The experimental group (n=103) received mindfulness training, and the control group (n=96) a conventional outpatient treatment for the same duration. The pre-post MAAS scores were analyzed to test the effectiveness of training, the psychometric properties of the scores, and differential item functioning (DIF) using the Rating Scale Model (RSM). Misfit in items 9 and 12, DIF in item 9, and Spanish translation problems in the items 5, 9 and 12 were observed. The repetition of the analysis without these items was decided. Appropriate dimensionality, fit and reliability values were obtained with the short version, MAAS-12. Contrary to previous studies, the MAAS was sensitive to treatment-associated change. However, the commonly used MAAS has some translation and metric problems, and should be revised. MAAS-12 is a better scale than MAAS but suffers from construct under-representation. Constructing tools from a coherent theoretical perspective is suggested, so that all mindfulness facets are represented. Copyright © 2013 SEP y SEPB. Published by Elsevier España. All rights reserved.

  14. Psychometric properties of the International Classification of Functioning, Disability and Health set for spinal cord injury nursing based on Rasch analysis.

    Science.gov (United States)

    Li, Kun; Yan, Tiebin; You, Liming; Xie, Sumei; Li, Yun; Tang, Jie; Wang, Yingmin; Gao, Yan

    2018-02-01

    To examine the psychometric properties of the International Classification of Functioning, Disability and Health (ICF) set for spinal cord injury nursing (ICF-SCIN) using Rasch analysis. A total of 140 spinal cord injury patients were recruited between December 2013 and March 2014 through convenience sampling. Nurses used the components body functions (BF), body structures (BS), and activities and participation (AP) of the ICF-SCIN to rate the patients' functioning. Rasch analysis was performed using RUMM 2030 software. In each component, categories were rescored from 01234 to 01112 because of reversed thresholds. Nine testlets were created to overcome local dependency. Four categories which fit to the Rasch model poorly were deleted. After modification, the components BF, BS, and AP showed good fit to the Rasch model with a Bonferroni-adjusted significant level (χ 2  =   86.29, p = 0.006; χ 2  =   22.44, p = 0.130; χ 2  =   39.92, p = 0.159). The person separation indices (PSIs) for the three components were 0.80, 0.54, and 0.97, respectively. No differential item functioning (DIF) was detected across age, gender, or educational level. The fit properties of the ICF set were satisfactory after modifications. The ICF-SCIN has the potential as a nursing assessment instrument for measuring the functioning of patients with spinal cord injury. Implications for rehabilitation The International Classification of Functioning, Disability and Health (ICF) set for spinal cord injury nursing contains a group of categories which can reflect the functioning of spinal cord injury patients from the perspective of nurses. The components body functions (BF), body structures (BS), and activities and participation (AP) of the ICF set for spinal cord injury achieved the fit to the Rasch model through rescoring, generating testlets, and deleting categories with poor fit. The ICF set for spinal cord injury nursing (ICF-SCIN) has the potential to be used as a

  15. Rating catatonia in patients with chronic schizophrenia: Rasch analysis of the Bush-Francis Catatonia Rating Scale.

    Science.gov (United States)

    Wong, Eric; Ungvari, Gabor S; Leung, Siu-Kau; Tang, Wai-Kwong

    2007-01-01

    Catatonic signs and symptoms are frequently observed in patients with chronic schizophrenia. Clinical surveys have suggested that the composition of catatonic syndrome occurring in chronic schizophrenia may be different from what is found in acute psychiatric disorders or medical conditions. Consequently, this patient population may need tailor-made rating instruments for catatonia. The aim of the present study was to examine the suitability and accuracy of using the Bush-Francis Catatonia Rating Scale (BFCRS) in chronic schizophrenia inpatients. The unidimensionality (optimal number of items; item fit), and the scoring scheme (the optimal number of scoring categories) of the BFCRS were determined in a random sample of 225 patients with chronic schizophrenia applying Rasch analysis. In addition, differential item functioning (DIF) analysis was also performed. The BFCRS proved to be unidimensional apart from three misfit and one marginally misfit items. The three misfit items were removed from the scale thereby constructing a revised version called BFCRS-R. Since the original BFCRS (BFCRS-O) showed no increase across items across steep gradients (poor endorsability of step calibrations), in BFCRS-R a binary scale ('absent' versus 'present' choices only) was constructed instead of the scoring scheme of 0-3. The 20-item BFCRS-R showed improved psychometric properties in that it had a higher item separation index than BFCRS-O. BFCRS-R mean logit was closer to zero indicating that the items on the scale and the subjects were better matched than in BFCRS-O. DIF analysis showed that certain items of both versions of BFCRS were influenced by the presence of negative symptoms. BFCRS-R is shorter and simpler than the original version and having better psychometric properties seems to be better suited for identifying and quantifying catatonia in chronic psychotic patients. Copyright (c) 2007 John Wiley & Sons, Ltd.

  16. Item Screening in Graphical Loglinear Rasch Models

    DEFF Research Database (Denmark)

    Kreiner, Svend; Christensen, Karl Bang

    2011-01-01

    In behavioural sciences, local dependence and DIF are common, and purification procedures that eliminate items with these weaknesses often result in short scales with poor reliability. Graphical loglinear Rasch models (Kreiner & Christensen, in Statistical Methods for Quality of Life Studies, ed....... by M. Mesbah, F.C. Cole & M.T. Lee, Kluwer Academic, pp. 187–203, 2002) where uniform DIF and uniform local dependence are permitted solve this dilemma by modelling the local dependence and DIF. Identifying loglinear Rasch models by a stepwise model search is often very time consuming, since...... the initial item analysis may disclose a great deal of spurious and misleading evidence of DIF and local dependence that has to disposed of during the modelling procedure. Like graphical models, graphical loglinear Rasch models possess Markov properties that are useful during the statistical analysis...

  17. Seeking missing pieces in science concept assessments: Reevaluating the Brief Electricity and Magnetism Assessment through Rasch analysis

    Science.gov (United States)

    Ding, Lin

    2014-02-01

    Discipline-based science concept assessments are powerful tools to measure learners' disciplinary core ideas. Among many such assessments, the Brief Electricity and Magnetism Assessment (BEMA) has been broadly used to gauge student conceptions of key electricity and magnetism (E&M) topics in college-level introductory physics courses. Differing from typical concept inventories that focus only on one topic of a subject area, BEMA covers a broad range of topics in the electromagnetism domain. In spite of this fact, prior studies exclusively used a single aggregate score to represent individual students' overall understanding of E&M without explicating the construct of this assessment. Additionally, BEMA has been used to compare traditional physics courses with a reformed course entitled Matter and Interactions (M&I). While prior findings were in favor of M&I, no empirical evidence was sought to rule out possible differential functioning of BEMA that may have inadvertently advantaged M&I students. In this study, we used Rasch analysis to seek two missing pieces regarding the construct and differential functioning of BEMA. Results suggest that although BEMA items generally can function together to measure the same construct of application and analysis of E&M concepts, several items may need further revision. Additionally, items that demonstrate differential functioning for the two courses are detected. Issues such as item contextual features and student familiarity with question settings may underlie these findings. This study highlights often overlooked threats in science concept assessments and provides an exemplar for using evidence-based reasoning to make valid inferences and arguments.

  18. Seeking missing pieces in science concept assessments: Reevaluating the Brief Electricity and Magnetism Assessment through Rasch analysis

    Directory of Open Access Journals (Sweden)

    Lin Ding

    2014-02-01

    Full Text Available Discipline-based science concept assessments are powerful tools to measure learners’ disciplinary core ideas. Among many such assessments, the Brief Electricity and Magnetism Assessment (BEMA has been broadly used to gauge student conceptions of key electricity and magnetism (E&M topics in college-level introductory physics courses. Differing from typical concept inventories that focus only on one topic of a subject area, BEMA covers a broad range of topics in the electromagnetism domain. In spite of this fact, prior studies exclusively used a single aggregate score to represent individual students’ overall understanding of E&M without explicating the construct of this assessment. Additionally, BEMA has been used to compare traditional physics courses with a reformed course entitled Matter and Interactions (M&I. While prior findings were in favor of M&I, no empirical evidence was sought to rule out possible differential functioning of BEMA that may have inadvertently advantaged M&I students. In this study, we used Rasch analysis to seek two missing pieces regarding the construct and differential functioning of BEMA. Results suggest that although BEMA items generally can function together to measure the same construct of application and analysis of E&M concepts, several items may need further revision. Additionally, items that demonstrate differential functioning for the two courses are detected. Issues such as item contextual features and student familiarity with question settings may underlie these findings. This study highlights often overlooked threats in science concept assessments and provides an exemplar for using evidence-based reasoning to make valid inferences and arguments.

  19. Construct validity of the psychological general well being index (PGWBI in a sample of patients undergoing treatment for stress-related exhaustion: a rasch analysis

    Directory of Open Access Journals (Sweden)

    Lundgren-Nilsson Åsa

    2013-01-01

    Full Text Available Abstract Purpose The Psychological General Well Being Index (PGWBI is a widely used scale across many conditions. Over time issues have been raised about the dimensional structure of the scale, and it has not yet been subjected to scrutiny by modern Psychometric approaches. The current study thus evaluates the PGWBI with Rasch- and factor analysis. Methods Consecutive patients recruited to a tertiary stress clinic were administered the PGBWI as part of routine clinical assessment at baseline and three months. Data from the scale was subjected to Factor Analyses and to Rasch analysis. In both cases adjustments for local independence violations were allowed. Results 179 patients were recruited, with a mean age of 43 years, and of whom 70% were female. An initial Confirmatory Factor Analysis (CFA with baseline data failed, but the modification indices also indicated considerable levels of local dependency requiring errors to be correlated. An EFA highlighted positive and negative effect domains. Rasch analysis confirmed that fit of data to the model was influenced by local dependency, and that in practice if the items from the six underlying domains were treated as six ‘super’ items, the scale was shown to measure one dominant construct of well being. An interval scale transformation was therefore possible. A significant improvement in well-being was observed over a three month period. Conclusion The PGWBI scale has satisfactory internal construct validity when tested with modern psychometric techniques, using data obtained from patients treated for stress-related exhaustion. The instrument has qualities that make it suitable also for monitoring well-being during interventions for stress-related exhaustion/clinical burnout.

  20. Rasch Analysis of the Activities-specific Balance Confidence (ABC) Scale in Older Adults Seeking Outpatient Rehabilitation Services.

    Science.gov (United States)

    Wang, Ying-Chih; Sindhu, Bhagwant; Lehman, Leigh; Li, Xiaoyan; Yen, Sheng-Che; Kapellusch, Jay

    2018-03-30

    Study Design Cross-sectional study of 5,012 older patients seeking outpatient rehabilitation therapy in 123 clinics. Background The Activities-Specific Balance Confidence (ABC) Scale measures confidence in performing various ambulatory activities without falling or experiencing a sense of unsteadiness. Objectives Our purposes were to: (1) examine the ABC Scale (0-100) using the Rasch analysis, (2) assess statistically reliable change, and (3) develop a functional staging to guide clinical interpretation of the patient's improvement. Methods We examined rating scale structure, item difficulty hierarchy, item fit, person-item match, separation index, differential item functioning (DIF), test precision, and unidimensionality. Additionally, we estimated the minimal detectable change (MDC) and developed a functional staging. Results Item 'walking outside on icy sidewalks' was the most difficult item, while 'reach for a small can off a shelf at eye level' was the easiest item. Overall, average patient ability estimates of 56.2 (20.3) was slightly higher than the average item difficulty estimates of 45.9 (7.8). With a separation index equaled to 3.65, the ABC items can differentiate persons into 5.2 statistically distinct strata. Most ABC items were free of DIF. For example, 'walk outside on icy sidewalks' was easier for patients who was underweight. Results supported unidimensionality of the ABC Scale, with the first factor explained 77% of the total variance. The estimated MDC was 15 points. We provided an example of functional staging application. Conclusion Results supported sound psychometric properties and clinical usage of the ABC Scale for older adults seeking outpatient rehabilitation therapy. Level of Evidence 2c. J Orthop Sports Phys Ther, Epub 30 Mar 2018. doi:10.2519/jospt.2018.8023.

  1. Do patients and health care professionals view the communication processes of clinical research differently? A Rasch analysis from a survey.

    Science.gov (United States)

    González-de Paz, Luis; Kostov, Belchin; Solans-Julian, Pilar; Navarro-Rubio, M Dolores; Sisó-Almirall, Antoni

    2015-10-01

    The increasing amount of the clinical research conducted in the primary health care has enabled extending research beyond traditional settings, but this transfer has implied some trade-offs. Health care professionals who conduct research with trusted patients require assuming the ethical standards of research and communication skills to enable patients' autonomy and freedom of choice. This study aims to measure the opinions of health professionals and patients on issues of communication in clinical research. A cross-sectional study with health care professionals and patients from primary health care centres in Barcelona (Spain). Each group completed a similar self-administered questionnaire. A Rasch model was fitted to data. After examination of goodness-of-fit, differences between groups were compared using analysis of variance, and patients' measures were calibrated to professionals' measures to compare overall mean measures. Professionals and patients found the ethical attitudes most difficult to endorse related to trust in clinical researchers and conflicts of interest. Patients' perceptions of professional ethical behaviour were significantly lower than professionals'. Different item functioning between nurses and family doctors was found in the item on seeking ethical collaboration when collaborating in clinical research. Effective knowledge of ethical norms was associated with greater perceived ethical values in clinical research and confidence in health care professionals among patients. Differences in the views of the communication process between patients and professionals could alert research boards, health care institutions and researchers to the need for greater transparency, trust and ethical instruction when patients are involved in clinical research. © 2015 John Wiley & Sons, Ltd.

  2. Use of Rasch Analysis to Evaluate and Refine the Community Balance and Mobility Scale for Use in Ambulatory Community-Dwelling Adults Following Stroke

    Science.gov (United States)

    Pollock, Courtney L.; Brouwer, Brenda; Garland, S. Jayne

    2016-01-01

    Background The Community Balance and Mobility Scale (CB&M) is increasingly used to evaluate walking balance following stroke. Objective This study applied Rasch analysis to evaluate and refine the CB&M for use in ambulatory community-dwelling adults following stroke. Methods The CB&M content was linked to task demands and motor skill classifications. Rasch analysis was used to evaluate internal construct validity (structural validity) and refine the CB&M for use with ambulatory community-dwelling adults following stroke. The CB&M data were collected at 3 time points: at discharge from inpatient rehabilitation and at 6 and 12 months postdischarge (N=238). Rasch analysis evaluated scale dimensionality, item and person fit, item response bias, scoring hierarchy, and targeting. Disordered scoring hierarchy was resolved by collapsing scoring categories. Highly correlated and “misfitting” items were removed. Sensitivity to change was evaluated with standardized response means (SRMs) and one-way repeated-measures analysis of variance. Results The CB&M was primarily linked to closed body transport task demands. Significant item-trait interaction, disordered scoring hierarchies, and multidimensionality were found. Scoring categories were collapsed in 15/19 items, and 5 misfitting items were removed. The resulting stroke-specific 14-item unidimensional CB&M (CB&MStroke) fit Rasch model expectations, with no item response bias, acceptable targeting (13% floor effects and 0% ceiling effects), and moderate-to-strong sensitivity to change at 6 months postdischarge (SRM=0.63; 95% confidence interval=−1.523, −0.142) and 12 months postdischarge (SRM=0.73; 95% confidence interval=−2.318, −0.760). Limitations Findings are limited to a modest-sized sample of individuals with mild-to-moderate balance impairment following stroke. Conclusions The CB&MStroke shows promise as a clinical scale for measuring change in walking balance in ambulatory community-dwelling adults

  3. Developing the Polish Educational Needs Assessment Tool (Pol-ENAT) in rheumatoid arthritis and systemic sclerosis: a cross-cultural validation study using Rasch analysis.

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    Sierakowska, Matylda; Sierakowski, Stanisław; Sierakowska, Justyna; Horton, Mike; Ndosi, Mwidimi

    2015-03-01

    To undertake cross-cultural adaptation and validation of the educational needs assessment tool (ENAT) for use with people with rheumatoid arthritis (RA) and systemic sclerosis (SSc) in Poland. The study involved two main phases: (1) cross-cultural adaptation of the ENAT from English into Polish and (2) Cross-cultural validation of Polish Educational Needs Assessment Tool (Pol-ENAT). The first phase followed an established process of cross-cultural adaptation of self-report measures. The second phase involved completion of the Pol-ENAT by patients and subjecting the data to Rasch analysis to assess the construct validity, unidimensionality, internal consistency and cross-cultural invariance. An adequate conceptual equivalence was achieved following the adaptation process. The dataset for validation comprised a total of 278 patients, 237 (85.3 %) of which were female. In each disease group (145, RA and 133, SSc), the 7 domains of the Pol-ENAT were found to fit the Rasch model, X (2)(df) = 16.953(14), p = 0.259 and 8.132(14), p = 0.882 for RA and SSc, respectively. Internal consistency of the Pol-ENAT was high (patient separation index = 0.85 and 0.89 for SSc and RA, respectively), and unidimensionality was confirmed. Cross-cultural differential item functioning (DIF) was detected in some subscales, and DIF-adjusted conversion tables were calibrated to enable cross-cultural comparison of data between Poland and the UK. Using a standard process in cross-cultural adaptation, conceptual equivalence was achieved between the original (UK) ENAT and the adapted Pol-ENAT. Fit to the Rasch model, confirmed that the construct validity, unidimensionality and internal consistency of the ENAT have been preserved.

  4. Inter-regional metric disadvantages when comparing countries’ happiness on a global scale. A Rasch based consequential validity analysis

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    Diego Fernando Rojas-Gualdrón

    2017-07-01

    Full Text Available Measurement confounding due to socioeconomic differences between world regions may bias the estimations of countries’ happiness and global inequality. Potential implications of this bias have not been researched. In this study, the consequential validity of the Happy Planet Index, 2012 as an indicator of global inequality is evaluated from the Rasch measurement perspective. Differential Item Functioning by world region and bias in the estimated magnitude of inequalities were analyzed. The recalculated measure showed a good fit to Rasch model assumptions. The original index underestimated relative inequalities between world regions by 20%. DIF had no effect on relative measures but affected absolute measures by overestimating world average happiness and underestimating its variance. These findings suggest measurement confounding by unmeasured characteristics. Metric disadvantages must be adjusted to make fair comparisons. Public policy decisions based on biased estimations could have relevant negative consequences on people’s health and well-being by not focusing efforts on real vulnerable populations.

  5. Development of a short scale for assessing economic environmental aspects in patients with spinal diseases using Rasch analysis.

    Science.gov (United States)

    Gecht, Judith; Mainz, Verena; Boecker, Maren; Clusmann, Hans; Geiger, Matthias Florian; Tingart, Markus; Quack, Valentin; Gauggel, Siegfried; Heinemann, Allen W; Müller, Christian-Andreas

    2017-10-10

    Economic environmental factors represent important barriers to participation and have deleterious effects on quality of life (QOL) in persons with spinal diseases (SpD). While economic factors are anchored in the International Classification of Functioning, Disability and Health, their influence on QOL and participation from patients' perspectives is an infrequent focus of research. The aim of the present research is to calibrate a culturally adapted Rasch-based questionnaire assessing economic QOL in patients with SpD. The 11-items of the German economic-QOL-scale were answered by 325 patients with SpD on a four-point Likert-scale. Fit to the Rasch measurement model was investigated by testing for stochastic ordering of the items, unidimensionality, local independence, and differential item functioning (DIF). After adjusting for local dependency, fit to the Rasch model was achieved with a non-significant item-trait interaction (chi-square df = 20  = 34.8, p = 0.021). The person separation reliability equaled 0.88, the scale was free from age- or gender-related DIF, and unidimensionality could be verified. The Rasch-based German version of the economic-QOL-scale represents a suitable instrument to investigate the influences of economic factors on patients' QOL at a group and individual level. It can be easily applied in research and practice and may be administered quickly in combination with other instruments. The short test duration implies a low test burden for patients and a minimum of time expenditure by clinicians when evaluating the results.

  6. Analysis of High School English Curriculum Materials through Rasch Measurement Model and Maxqda

    Science.gov (United States)

    Batdi, Veli; Elaldi, Senel

    2016-01-01

    The purpose of the study is to analyze high school English curriculum materials (ECM) through FACETS analysis and MAXQDA-11 programs. The mixed methods approach, both quantitative and qualitative methods, were used in three samples including English teachers in Elazig during the 2014-2015 academic year. While the quantitative phase of the study…

  7. Utilizing Multifaceted Rasch Measurement through Facets to Evaluate Science Education Data Sets Composed of Judges, Respondents, and Rating Scale Items: An Exemplar Utilizing the Elementary Science Teaching Analysis Matrix Instrument

    Science.gov (United States)

    Boone, William J.; Townsend, J. Scott; Staver, John R.

    2016-01-01

    When collecting data, science education researchers frequently have multiple respondents evaluate multiple artifacts using multiple criteria. Herein, the authors introduce Multifaceted Rasch Measurement (MFRM) analysis and explain why MFRM must be used when "judges'" data are collected. The authors use data from elementary science…

  8. Cross-cultural validity of the ABILOCO questionnaire for individuals with stroke, based on Rasch analysis.

    Science.gov (United States)

    Avelino, Patrick Roberto; Magalhães, Lívia Castro; Faria-Fortini, Iza; Basílio, Marluce Lopes; Menezes, Kênia Kiefer Parreiras; Teixeira-Salmela, Luci Fuscaldi

    2018-06-01

    The purpose of this study was to evaluate the cross-cultural validity of the Brazilian version of the ABILOCO questionnaire for stroke subjects. Cross-cultural adaptation of the original English version of the ABILOCO to the Brazilian-Portuguese language followed standardized procedures. The adapted version was administered to 136 stroke subjects and its measurement properties were assessed using Rash analysis. Cross-cultural validity was based on cultural invariance analyses. Goodness-of-fit analysis revealed one misfitting item. The principal component analysis of the residuals showed that the first dimension explained 45% of the variance in locomotion ability; however, the eigenvalue was 1.92. The ABILOCO-Brazil divided the sample into two levels of ability and the items into about seven levels of difficulty. The item-person map showed some ceiling effect. Cultural invariance analyses revealed that although there were differences in the item calibrations between the ABILOCO-original and ABILOCO-Brazil, they did not impact the measures of locomotion ability. The ABILOCO-Brazil demonstrated satisfactory measurement properties to be used within both clinical and research contexts in Brazil, as well cross-cultural validity to be used in international/multicentric studies. However, the presence of ceiling effect suggests that it may not be appropriate for the assessment of individuals with high levels of locomotion ability. Implications for rehabilitation Self-report measures of locomotion ability are clinically important, since they describe the abilities of the individuals within real life contexts. The ABILOCO questionnaire, specific for stroke survivors, demonstrated satisfactory measurement properties, but may not be most appropriate to assess individuals with high levels of locomotion ability The results of the cross-cultural validity showed that the ABILOCO-Original and the ABILOCO-Brazil calibrations may be used interchangeable.

  9. A Rasch Analysis of the Charcot-Marie-Tooth Neuropathy Score (CMTNS) in a Cohort of Charcot-Marie-Tooth Type 1A Patients.

    Science.gov (United States)

    Wang, Wenjia; Guedj, Mickaël; Bertrand, Viviane; Foucquier, Julie; Jouve, Elisabeth; Commenges, Daniel; Proust-Lima, Cécile; Murphy, Niall P; Blin, Olivier; Magy, Laurent; Cohen, Daniel; Attarian, Shahram

    2017-01-01

    The Charcot-Marie-Tooth Neuropathy Score (CMTNS) was developed as a main efficacy endpoint for application in clinical trials of Charcot-Marie-Tooth disease type 1A (CMT1A). However, the sensitivity of the CMTNS for measuring disease severity and progression in CMT1A patients has been questioned. Here, we applied a Rasch analysis in a French cohort of patients to evaluate the psychometrical properties of the CMTNS. Overall, our analysis supports the validity of the CMTNS for application to CMT1A patients though with some limitations such as certain items of the CMTNS being more suitable for moderate to severe forms of the disease, and some items being disordered. We suggest that additional items and/or categories be considered to better assess mild-to-moderate patients.

  10. A Rasch Analysis of the Charcot-Marie-Tooth Neuropathy Score (CMTNS in a Cohort of Charcot-Marie-Tooth Type 1A Patients.

    Directory of Open Access Journals (Sweden)

    Wenjia Wang

    Full Text Available The Charcot-Marie-Tooth Neuropathy Score (CMTNS was developed as a main efficacy endpoint for application in clinical trials of Charcot-Marie-Tooth disease type 1A (CMT1A. However, the sensitivity of the CMTNS for measuring disease severity and progression in CMT1A patients has been questioned. Here, we applied a Rasch analysis in a French cohort of patients to evaluate the psychometrical properties of the CMTNS. Overall, our analysis supports the validity of the CMTNS for application to CMT1A patients though with some limitations such as certain items of the CMTNS being more suitable for moderate to severe forms of the disease, and some items being disordered. We suggest that additional items and/or categories be considered to better assess mild-to-moderate patients.

  11. Validity of the school setting interview for students with special educational needs in regular high school - a Rasch analysis.

    Science.gov (United States)

    Yngve, Moa; Munkholm, Michaela; Lidström, Helene; Hemmingsson, Helena; Ekbladh, Elin

    2018-01-12

    Participation in education is a vital component of adolescents' everyday life and a determinant of health and future opportunities in adult life. The School Setting Interview (SSI) is an instrument which assesses student-environment fit and reflects the potential needs for adjustments to enhance students' participation in school activities. The aim of the study was to investigate the psychometric properties of the SSI for students with special educational needs in regular high school. A sample of 509 students with special educational needs was assessed with the SSI. The polytomous unrestricted Rasch model was used to analyze the psychometric properties of the SSI regarding targeting, model fit, differential item functioning (DIF), response category functioning and unidimensionality. The SSI generally confirmed fit to assumptions of the Rasch model. Reliability was acceptable (0.73) and the SSI scale was able to separate students into three different levels of student-environment fit. DIF among gender was detected in item "Remember things" and in item "Homework" DIF was detected among students with or without diagnosis. All items had disordered thresholds. The SSI demonstrated unidimensionality and no response dependence was present among items. The results suggest that the SSI is valid for use among students with special educational needs in order to provide and evaluate environmental adjustments. However, the items with the detected DIF and the SSI rating scale with its disordered thresholds needs to be further scrutinized.

  12. Measuring Health-Related Quality of Life in Strabismus: A Modification of the Adult Strabismus-20 (AS-20 Questionnaire Using Rasch Analysis.

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    Vijaya K Gothwal

    Full Text Available To evaluate the psychometric properties of the Adult Strabismus-20 (AS-20- a health-related quality of life (HRQoL questionnaire in adults with strabismus, and if flawed, to revise the AS-20 and its subscales creating valid measurement scales.584 adults (meanage, 27.5 years with strabismus were recruited from an outpatient clinic at a South Indian tertiary eye care centre and were administered the AS-20 questionnaire.The AS-20 was translated and back translated into two Indian languages. The AS-20 and its two 10-item subscales - 'psychosocial' and 'function'were assessed separately for fit to the Rasch model, including an assessment of the rating scale, unidimensionality (by principal components analysis, measurement precision by person separation reliability, PSR, targeting, and differential item functioning (DIF; notable > 1.0 logits.Response categories were not used as intended, thereby, required re-organization and reducing their number from 5 to 3. The AS-20 had adequate measurement precision (PSR = 0.87 but lacked unidimensionality; however, deletion of the six multi-dimensionality causing items and an additional three misfitting items resulted in 11-item unidimensional questionnaire (AS-11. Two items failed to satisfy the model expectations in the 'psychosocial' subscale and were deleted - resulting in an 8-item unidimensional scale with adequate PSR (0.81 and targeting (0.23 logits. One item misfit in the 'function' subscale and was deleted-resulting in a 9 item Rasch-revised unidimensional subscale with acceptable PSR (0.80 and targeting (0.97 logits.None of the items displayed notable DIF by age, gender and level of education.The AS-11 and its two Rasch-revised subscales - 8-item psychosocial and 9-item function subscale may be more appropriate than the original AS-20 and its two 10-item subscales for use as unidimensional measures of HRQoL in adults with strabismus in India. Further work is required to establish the validity of the

  13. Internal construct validity of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS): a Rasch analysis using data from the Scottish Health Education Population Survey.

    Science.gov (United States)

    Stewart-Brown, Sarah; Tennant, Alan; Tennant, Ruth; Platt, Stephen; Parkinson, Jane; Weich, Scott

    2009-02-19

    The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS) was developed to meet demand for instruments to measure mental well-being. It comprises 14 positively phrased Likert-style items and fulfils classic criteria for scale development. We report here the internal construct validity of WEMWBS from the perspective of the Rasch measurement model. The model was applied to data collected from 779 respondents in Wave 12 (Autumn 2006) of the Scottish Health Education Population Survey. Respondents were aged 16-74 (average 41.9) yrs. Initial fit to model expectations was poor. The items 'I've been feeling good about myself', 'I've been interested in new things' and 'I've been feeling cheerful' all showed significant misfit to model expectations, and were deleted. This led to a marginal improvement in fit to the model. After further analysis, more items were deleted and a strict unidimensional seven item scale (the Short Warwick Edinburgh Mental Well-Being Scale (SWEMWBS)) was resolved. Many items deleted because of misfit with model expectations showed considerable bias for gender. Two retained items also demonstrated bias for gender but, at the scale level, cancelled out. One further retained item 'I've been feeling optimistic about the future' showed bias for age. The correlation between the 14 item and 7 item versions was 0.954.Given fit to the Rasch model, and strict unidimensionality, SWEMWBS provides an interval scale estimate of mental well-being. A short 7 item version of WEMWBS was found to satisfy the strict unidimensionality expectations of the Rasch model, and be largely free of bias. This scale, SWEMWBS, provides a raw score-interval scale transformation for use in parametric procedures. In terms of face validity, SWEMWBS presents a more restricted view of mental well-being than the 14 item WEMWBS, with most items representing aspects of psychological and eudemonic well-being, and few covering hedonic well-being or affect. However, robust measurement

  14. Internal construct validity of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS: a Rasch analysis using data from the Scottish Health Education Population Survey

    Directory of Open Access Journals (Sweden)

    Platt Stephen

    2009-02-01

    Full Text Available Abstract Background The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS was developed to meet demand for instruments to measure mental well-being. It comprises 14 positively phrased Likert-style items and fulfils classic criteria for scale development. We report here the internal construct validity of WEMWBS from the perspective of the Rasch measurement model. Methods The model was applied to data collected from 779 respondents in Wave 12 (Autumn 2006 of the Scottish Health Education Population Survey. Respondents were aged 16–74 (average 41.9 yrs. Results Initial fit to model expectations was poor. The items 'I've been feeling good about myself', 'I've been interested in new things' and 'I've been feeling cheerful' all showed significant misfit to model expectations, and were deleted. This led to a marginal improvement in fit to the model. After further analysis, more items were deleted and a strict unidimensional seven item scale (the Short Warwick Edinburgh Mental Well-Being Scale (SWEMWBS was resolved. Many items deleted because of misfit with model expectations showed considerable bias for gender. Two retained items also demonstrated bias for gender but, at the scale level, cancelled out. One further retained item 'I've been feeling optimistic about the future' showed bias for age. The correlation between the 14 item and 7 item versions was 0.954. Given fit to the Rasch model, and strict unidimensionality, SWEMWBS provides an interval scale estimate of mental well-being. Conclusion A short 7 item version of WEMWBS was found to satisfy the strict unidimensionality expectations of the Rasch model, and be largely free of bias. This scale, SWEMWBS, provides a raw score-interval scale transformation for use in parametric procedures. In terms of face validity, SWEMWBS presents a more restricted view of mental well-being than the 14 item WEMWBS, with most items representing aspects of psychological and eudemonic well-being, and few covering

  15. A Rasch analysis of a questionnaire designed to evaluate psychiatric patient attitudes and knowledge after attending a pharmacist-led patient medication education group.

    Science.gov (United States)

    Norman, Sarah; Davis, Erica; Goldstone, Lisa W; Villa, Lorenzo; Warholak, Terri L

    2014-01-01

    There are many barriers that prevent persons with mental health disorders from achieving remission, including medication nonadherence. Research on the impact of pharmacist-led patient medication education groups on patient attitudes, knowledge and adherence is limited. To evaluate the reliability and validity of the Medication Attitudes and Knowledge Questionnaire (MAKQ). A retrospective pre-post questionnaire was distributed to patients. Variables collected included: patient self-reported medication knowledge and attitudes, patient demographics, number of previous psychiatric hospitalizations, whether the patient attended the whole meeting or only a portion, and outpatient pharmacist relationships. Knowledge and attitude items were measured on a 4-point scale with a range of options from "Agree" to "Disagree." Rasch analysis was conducted to ensure all items measured the same construct and to assess scale and item reliability and validity. Additionally, the Rasch technique evaluated the change in each person's self-perceived attitudes, knowledge, and confidence in self-managing medications from pre- to post-intervention if the data fit the model. A z-test was used to evaluate gaps in content validity. Sixty patients responded to the MAKQ over the 16-week data collection period. Analysis showed that the 4-point rating scale was not useful and that negatively worded items should be eliminated. Gaps identified in instrument item content were not statistically significant (p > 0.05), indicating comprehensive content validity. Medication attitudes and knowledge items on the retrospective pre-post questionnaire were valid and reliable. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Measurement properties of the Health Literacy Questionnaire (HLQ) among older adults who present to the emergency department after a fall: a Rasch analysis.

    Science.gov (United States)

    Morris, Rebecca L; Soh, Sze-Ee; Hill, Keith D; Buchbinder, Rachelle; Lowthian, Judy A; Redfern, Julie; Etherton-Beer, Christopher D; Hill, Anne-Marie; Osborne, Richard H; Arendts, Glenn; Barker, Anna L

    2017-08-29

    Health literacy is an important concept associated with participation in preventive health initiatives, such as falls prevention programs. A comprehensive health literacy measurement tool, appropriate for this population, is required. The aim of this study was to evaluate the measurement properties of the Health Literacy Questionnaire (HLQ) in a cohort of older adults who presented to a hospital emergency department (ED) after a fall. Older adults who presented to an ED after a fall had their health literacy assessed using the HLQ (n = 433). Data were collected as part of a multi-centre randomised controlled trial of a falls prevention program. Measurement properties of the HLQ were assessed using Rasch analysis. All nine scales of the HLQ were unidimensional, with good internal consistency reliability. No item bias was found for most items (43 of 44). A degree of overall misfit to the Rasch model was evident for six of the nine HLQ scales. The majority of misfit indicated content overlap between some items and does not compromise measurement. A measurement gap was identified for this cohort at mid to high HLQ score. The HLQ demonstrated good measurement properties in a cohort of older adults who presented to an ED after a fall. The summation of the HLQ items within each scale, providing unbiased information on nine separate areas of health literacy, is supported. Clinicians, researchers and policy makers may have confidence using the HLQ scale scores to gain information about health literacy in older people presenting to the ED after a fall. This study was registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12614000336684 (27 March 2014).

  17. Development and validation of parallel short forms PaSA-cardio for the assessment of general anxiety in cardiovascular rehabilitation patients using Rasch analysis.

    Science.gov (United States)

    Abberger, Birgit; Haschke, Anne; Tully, Phillip J; Forkmann, Thomas; Berger, Janna; Wirtz, Markus; Bengel, Juergen; Baumeister, Harald

    2017-01-01

    To develop and validate parallel short forms for the assessment of general anxiety in cardiovascular rehabilitation patients, that facilitate repeated measurement over time without contamination from residual practice effect variance. Development of the parallel short forms using Rasch analysis. Validation study. Cardiac rehabilitation centres in Germany. Cardiovascular rehabilitation patients. Not applicable. Parallel short forms PaSA-cardio, Hospital Anxiety and Depression Scale, Short Form Health Survey SF-12 and Structured Clinical Interview for DSM-IV Axis I Disorders. Each version of the parallel short forms (PaSA-cardio-I and PaSA-cardio-II) comprises ten items. The two forms fitted to the Rasch model with a non-significant item-trait interaction (PaSA-cardio-I: chi-square = 39.49, degrees of freedom = 30, probability = 0.12; PaSA-cardio-II: chi-square = 26.56, degrees of freedom = 30, probability = 0.65). Person-separation reliability was 0.75/0.76. Unidimensionality could be verified. Correlation between the two models was 0.94 and 0.95, and correlations with the underlying item bank were 0.95 and 0.93. Validity could be confirmed. The area under the curve was between 0.88 and 0.97 for PaSA-cardio-I and between 0.92 and 0.95 for PaSA-cardio-II. Assessment of general anxiety in cardiovascular rehabilitation patients with the PaSA-cardio was valid, economical and accurate. The two forms of the PaSA-cardio are equivalent and allow retest without contamination from residual practice effect variance.

  18. Predicting responses from Rasch measures.

    Science.gov (United States)

    Linacre, John M

    2010-01-01

    There is a growing family of Rasch models for polytomous observations. Selecting a suitable model for an existing dataset, estimating its parameters and evaluating its fit is now routine. Problems arise when the model parameters are to be estimated from the current data, but used to predict future data. In particular, ambiguities in the nature of the current data, or overfit of the model to the current dataset, may mean that better fit to the current data may lead to worse fit to future data. The predictive power of several Rasch and Rasch-related models are discussed in the context of the Netflix Prize. Rasch-related models are proposed based on Singular Value Decomposition (SVD) and Boltzmann Machines.

  19. University Programme Preferences of High School Science Students in Singapore and Reasons that Matter in their Preferences: A Rasch analysis

    Science.gov (United States)

    Oon, Pey-Tee; Subramaniam, R.

    2015-01-01

    This study explored an under-researched area in science education-the university programmes preferred by high school students who take physical science subjects and the reasons that matter in their preferences. A total of 1,071 upper secondary and pre-university students in Singapore, who take physical science subjects among their range of subjects, participated in this study. A survey method was adopted and the Rasch model was used to analyse the data. Overall, Business Studies was ranked as the predominant choice; nonetheless, scientific programmes such as Science, Engineering, and Mathematics are generally still well liked by the students. When gender differences were examined, we found that students largely followed gender-typical programme preferences, in which males tend to incline towards Engineering while females tend to incline towards Arts and Social Sciences. Students prefer a university programme based on their individual interest and ability, with career aspiration and remuneration coming next. Interestingly, females place greater emphasis on career aspiration than males. Some implications of the study are discussed.

  20. Validation of the Dutch version of the Swallowing Quality-of-Life Questionnaire (DSWAL-QoL) and the adjusted DSWAL-QoL (aDSWAL-QoL) using item analysis with the Rasch model: a pilot study.

    Science.gov (United States)

    Simpelaere, Ingeborg S; Van Nuffelen, Gwen; De Bodt, Marc; Vanderwegen, Jan; Hansen, Tina

    2017-04-07

    The Swallowing Quality-of-Life Questionnaire (SWAL-QoL) is considered the gold standard for assessing health-related QoL in oropharyngeal dysphagia. The Dutch translation (DSWAL-QoL) and its adjusted version (aDSWAL-QoL) have been validated using classical test theory (CTT). However, these scales have not been tested against the Rasch measurement model, which is required to establish the structural validity and objectivity of the total scale and subscale scores. Thus, the purpose of this study was to examine the psychometric properties of these scales using item analysis according to the Rasch model. Item analysis with the Rasch model was performed using RUMM2030 software with previously collected data from a validation study of 108 patients. The assessment included evaluations of overall model fit, reliability, unidimensionality, threshold ordering, individual item and person fits, differential item functioning (DIF), local item dependency (LID) and targeting. The analysis could not establish the psychometric properties of either of the scales or their subscales because they did not fit the Rasch model, and multidimensionality, disordered thresholds, DIF, and/or LID were found. The reliability and power of fit were high for the total scales (PSI = 0.93) but low for most of the subscales (PSI model. Relying on the DSWAL-QoL and aDSWAL-QoL total and subscale scores to make conclusions regarding dysphagia-related HRQoL should be treated with caution before the structural validity and objectivity of both scales have been established. A larger and well-targeted sample is recommended to derive definitive conclusions about the items and scales. Solutions for the psychometric weaknesses suggested by the model and practical implications are discussed.

  1. The Major Depressive Disorder Hierarchy: Rasch Analysis of 6 items of the Hamilton Depression Scale Covering the Continuum of Depressive Syndrome.

    Science.gov (United States)

    Primo de Carvalho Alves, Lucas; Pio de Almeida Fleck, Marcelo; Boni, Aline; Sica da Rocha, Neusa

    2017-01-01

    Melancholic features of depression (MFD) seem to be a unidimensional group of signs and symptoms. However, little importance has been given to the evaluation of what features are related to a more severe disorder. That is, what are the MFD that appear only in the most depressed patients. We aim to demonstrate how each MFD is related to the severity of the major depressive disorder. We evaluated both the Hamilton depression rating scale (HDRS-17) and its 6-item melancholic subscale (HAM-D6) in 291 depressed inpatients using Rasch analysis, which computes the severity of each MFD. Overall measures of model fit were mean (±SD) of items and persons residual = 0 (±1); low χ2 value; p>0.01. For the HDRS-17 model fit, mean (±SD) of item residuals = 0.35 (±1.4); mean (±SD) of person residuals = -0.15 (±1.09); χ2 = 309.74; pdepressed mood, work and activities, somatic symptoms, psychic anxiety, guilt feelings, and psychomotor retardation. Depressed mood is less severe, while guilt feelings and psychomotor retardation are more severe MFD in a psychiatric hospitalization. Understanding depression as a continuum of symptoms can improve the understanding of the disorder and may improve its perspective of treatment.

  2. Rasch analysis of the Pediatric Evaluation of Disability Inventory-computer adaptive test (PEDI-CAT) item bank for children and young adults with spinal muscular atrophy.

    Science.gov (United States)

    Pasternak, Amy; Sideridis, Georgios; Fragala-Pinkham, Maria; Glanzman, Allan M; Montes, Jacqueline; Dunaway, Sally; Salazar, Rachel; Quigley, Janet; Pandya, Shree; O'Riley, Susan; Greenwood, Jonathan; Chiriboga, Claudia; Finkel, Richard; Tennekoon, Gihan; Martens, William B; McDermott, Michael P; Fournier, Heather Szelag; Madabusi, Lavanya; Harrington, Timothy; Cruz, Rosangel E; LaMarca, Nicole M; Videon, Nancy M; Vivo, Darryl C De; Darras, Basil T

    2016-12-01

    In this study we evaluated the suitability of a caregiver-reported functional measure, the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT), for children and young adults with spinal muscular atrophy (SMA). PEDI-CAT Mobility and Daily Activities domain item banks were administered to 58 caregivers of children and young adults with SMA. Rasch analysis was used to evaluate test properties across SMA types. Unidimensional content for each domain was confirmed. The PEDI-CAT was most informative for type III SMA, with ability levels distributed close to 0.0 logits in both domains. It was less informative for types I and II SMA, especially for mobility skills. Item and person abilities were not distributed evenly across all types. The PEDI-CAT may be used to measure functional performance in SMA, but additional items are needed to identify small changes in function and best represent the abilities of all types of SMA. Muscle Nerve 54: 1097-1107, 2016. © 2016 Wiley Periodicals, Inc.

  3. Using Rasch Analysis to Examine the Dimensionality Structure and Differential Item Functioning of the Arabic Version of the Perceived Physical Ability Scale for Children

    Science.gov (United States)

    Abd-El-Fattah, Sabry M.; AL-Sinani, Yousra; El Shourbagi, Sahar; Fakhroo, Hessa A.

    2014-01-01

    This study uses the Rasch model technique to examine the dimensionality structure and differential item functioning of the Arabic version of the Perceived Physical Ability Scale for Children (PPASC). A sample of 220 Omani fourth graders (120 males and 100 females) responded to an Arabic translated version of the PPASC. Data on students'…

  4. Redefining diagnostic symptoms of depression using Rasch analysis: testing an item bank suitable for DSM-V and computer adaptive testing.

    Science.gov (United States)

    Mitchell, Alex J; Smith, Adam B; Al-salihy, Zerak; Rahim, Twana A; Mahmud, Mahmud Q; Muhyaldin, Asma S

    2011-10-01

    We aimed to redefine the optimal self-report symptoms of depression suitable for creation of an item bank that could be used in computer adaptive testing or to develop a simplified screening tool for DSM-V. Four hundred subjects (200 patients with primary depression and 200 non-depressed subjects), living in Iraqi Kurdistan were interviewed. The Mini International Neuropsychiatric Interview (MINI) was used to define the presence of major depression (DSM-IV criteria). We examined symptoms of depression using four well-known scales delivered in Kurdish. The Partial Credit Model was applied to each instrument. Common-item equating was subsequently used to create an item bank and differential item functioning (DIF) explored for known subgroups. A symptom level Rasch analysis reduced the original 45 items to 24 items of the original after the exclusion of 21 misfitting items. A further six items (CESD13 and CESD17, HADS-D4, HADS-D5 and HADS-D7, and CDSS3 and CDSS4) were removed due to misfit as the items were added together to form the item bank, and two items were subsequently removed following the DIF analysis by diagnosis (CESD20 and CDSS9, both of which were harder to endorse for women). Therefore the remaining optimal item bank consisted of 17 items and produced an area under the curve (AUC) of 0.987. Using a bank restricted to the optimal nine items revealed only minor loss of accuracy (AUC = 0.989, sensitivity 96%, specificity 95%). Finally, when restricted to only four items accuracy was still high (AUC was still 0.976; sensitivity 93%, specificity 96%). An item bank of 17 items may be useful in computer adaptive testing and nine or even four items may be used to develop a simplified screening tool for DSM-V major depressive disorder (MDD). Further examination of this item bank should be conducted in different cultural settings.

  5. From Rasch scores to regression

    DEFF Research Database (Denmark)

    Christensen, Karl Bang

    2006-01-01

    Rasch models provide a framework for measurement and modelling latent variables. Having measured a latent variable in a population a comparison of groups will often be of interest. For this purpose the use of observed raw scores will often be inadequate because these lack interval scale propertie...

  6. Reliability in the Rasch Model

    Czech Academy of Sciences Publication Activity Database

    Martinková, Patrícia; Zvára, K.

    2007-01-01

    Roč. 43, č. 3 (2007), s. 315-326 ISSN 0023-5954 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : Cronbach's alpha * Rasch model * reliability Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.552, year: 2007 http://dml.cz/handle/10338.dmlcz/135776

  7. Monte Carlo tests of the Rasch model based on scalability coefficients

    DEFF Research Database (Denmark)

    Christensen, Karl Bang; Kreiner, Svend

    2010-01-01

    that summarizes the number of Guttman errors in the data matrix. These coefficients are shown to yield efficient tests of the Rasch model using p-values computed using Markov chain Monte Carlo methods. The power of the tests of unequal item discrimination, and their ability to distinguish between local dependence......For item responses fitting the Rasch model, the assumptions underlying the Mokken model of double monotonicity are met. This makes non-parametric item response theory a natural starting-point for Rasch item analysis. This paper studies scalability coefficients based on Loevinger's H coefficient...

  8. Cross-cultural validity of the Spanish version of PHQ-9 among pregnant Peruvian women: a Rasch item response theory analysis.

    Science.gov (United States)

    Zhong, Qiuyue; Gelaye, Bizu; Fann, Jesse R; Sanchez, Sixto E; Williams, Michelle A

    2014-04-01

    We sought to evaluate the validity of the Spanish language version of the patient health questionnaire-9 (PHQ-9) depression scale in a large sample of pregnant Peruvian women using Rasch item response theory (IRT) approaches. We further sought to examine the appropriateness of the response formats, reliability and potential differential item functioning (DIF) by maternal age, educational attainment and employment status. This cross-sectional study was conducted among 1520 pregnant women in Lima, Peru. A structured interview was used to collect information on demographic characteristics and PHQ-9 items. Data from the PHQ-9 were fitted to the Rasch IRT model and tested for appropriate category ordering, the assumptions of unidimensionality and local independence, item fit, reliability and presence of DIF. The Spanish language version of PHQ-9 demonstrated unidimensionality, local independence, and acceptable fit for the Rasch IRT model. However, we detected disordered response categories for the original four response categories. After collapsing "more than half the days" and "nearly every day", the response categories ordered properly and the PHQ-9 fit the Rasch IRT model. The PHQ-9 had moderate internal consistency (person separation index, PSI=0.72). Additionally, the items of PHQ-9 were free of DIF with regard to age, educational attainment, and employment status. The Spanish language version of the PHQ-9 was shown to have item properties of an effective screening instrument. Collapsing rating scale categories and reconstructing three-point Likert scale for all items improved the fit of the instrument. Future studies are warranted to establish new cutoff scores and criterion validity of the three-point Likert scale response options for the Spanish language version of the PHQ-9. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Internal construct validity of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS): a Rasch analysis using data from the Scottish Health Education Population Survey

    OpenAIRE

    Platt Stephen; Tennant Ruth; Tennant Alan; Stewart-Brown Sarah; Parkinson Jane; Weich Scott

    2009-01-01

    Abstract Background The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS) was developed to meet demand for instruments to measure mental well-being. It comprises 14 positively phrased Likert-style items and fulfils classic criteria for scale development. We report here the internal construct validity of WEMWBS from the perspective of the Rasch measurement model. Methods The model was applied to data collected from 779 respondents in Wave 12 (Autumn 2006) of the Scottish Health Education Popu...

  10. A comparison of three methods of assessing differential item functioning (DIF) in the Hospital Anxiety Depression Scale: ordinal logistic regression, Rasch analysis and the Mantel chi-square procedure.

    Science.gov (United States)

    Cameron, Isobel M; Scott, Neil W; Adler, Mats; Reid, Ian C

    2014-12-01

    It is important for clinical practice and research that measurement scales of well-being and quality of life exhibit only minimal differential item functioning (DIF). DIF occurs where different groups of people endorse items in a scale to different extents after being matched by the intended scale attribute. We investigate the equivalence or otherwise of common methods of assessing DIF. Three methods of measuring age- and sex-related DIF (ordinal logistic regression, Rasch analysis and Mantel χ(2) procedure) were applied to Hospital Anxiety Depression Scale (HADS) data pertaining to a sample of 1,068 patients consulting primary care practitioners. Three items were flagged by all three approaches as having either age- or sex-related DIF with a consistent direction of effect; a further three items identified did not meet stricter criteria for important DIF using at least one method. When applying strict criteria for significant DIF, ordinal logistic regression was slightly less sensitive. Ordinal logistic regression, Rasch analysis and contingency table methods yielded consistent results when identifying DIF in the HADS depression and HADS anxiety scales. Regardless of methods applied, investigators should use a combination of statistical significance, magnitude of the DIF effect and investigator judgement when interpreting the results.

  11. Análise pelo modelo de Rasch do ditado ADAPE: considerações da ortografia = Analysis by Rasch model of ADAPE dictation: considerations from orthography = Análisis por el modelo de Rasch del dictado ADAPE: consideraciones de la ortografía

    Directory of Open Access Journals (Sweden)

    Caliatto, Susana Gakyia

    2014-01-01

    Full Text Available Este estudo teve como objetivo identificar as palavras com maior dificuldade de escrita, com base na análise pelo modelo de Rasch, e indicar a composição das palavras do ditado ADAPE que produzem mais erros. Participaram 221 estudantes, com idades compreendidas entre 6 e 11 anos, do segundo ao quinto ano de uma escola particular do estado de Minas Gerais. A média da dificuldade dos itens foi estabelecida convencionalmente como zero. Os resultados indicaram que a palavra Cássio foi a mais difícil. Outras sete palavras também foram muito difíceis. Mostrou-se que o ditado contém palavras que exigem diferentes conhecimentos ortográficos, o que permite avaliar os estudantes em distintas etapas da alfabetização. As palavras foram discutidas em função de categorias de erros da língua portuguesa

  12. From Rasch scores to regression

    DEFF Research Database (Denmark)

    Christensen, Karl Bang

    2006-01-01

    Rasch models provide a framework for measurement and modelling latent variables. Having measured a latent variable in a population a comparison of groups will often be of interest. For this purpose the use of observed raw scores will often be inadequate because these lack interval scale propertie....... This paper compares two approaches to group comparison: linear regression models using estimated person locations as outcome variables and latent regression models based on the distribution of the score....

  13. Rasch analysis of the Mini-Mental Adjustment to Cancer Scale (mini-MAC among a heterogeneous sample of long-term cancer survivors: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Zucca Alison

    2012-05-01

    Full Text Available Abstract Background The mini-Mental Adjustment to Cancer Scale (mini-MAC is a well-recognised, popular measure of coping in psycho-oncology and assesses five cancer-specific coping strategies. It has been suggested that these five subscales could be grouped to form the over-arching adaptive and maladptive coping subscales to facilitate the interpretation and clinical application of the scale. Despite the popularity of the mini-MAC, few studies have examined its psychometric properties among long-term cancer survivors, and further validation of the mini-MAC is needed to substantiate its use with the growing population of survivors. Therefore, this study examined the psychometric properties and dimensionality of the mini-MAC in a sample of long-term cancer survivors using Rasch analysis. Methods RUMM 2030 was used to analyse the mini-MAC data (n=851. Separate Rasch analyses were conducted for each of the original mini-MAC subscales as well as the over-arching adaptive and maladaptive coping subscales to examine summary and individual model fit statistics, person separation index (PSI, response format, local dependency, targeting, item bias (or differential item functioning -DIF, and dimensionality. Results For the fighting spirit, fatalism, and helplessness-hopelessness subscales, a revised three-point response format seemed more optimal than the original four-point response. To achieve model fit, items were deleted from four of the five subscales – Anxious Preoccupation items 7, 25, and 29; Cognitive Avoidance items 11 and 17; Fighting Spirit item 18; and Helplessness-Hopelessness items 16 and 20. For those subscales with sufficient items, analyses supported unidimensionality. Combining items to form the adaptive and maladaptive subscales was partially supported. Conclusions The original five subscales required item deletion and/or rescaling to improve goodness of fit to the Rasch model. While evidence was found for overarching subscales of

  14. DIF Cancellation in the Rasch Model.

    Science.gov (United States)

    Wyse, Adam E

    2013-01-01

    Differential item functioning (DIF) cancellation occurs when the cumulative effect of an item or set of items exhibiting DIF against one subgroup cancels with other items that exhibit DIF against the comparison group and hence results in non-existent DIF at the test level. This paper investigates DIF cancellation in the context of Rasch measurement. It is shown that this phenomenon is not a property of the Rasch model, but rather, a function of the manner in which item parameters are estimated and the way that DIF impacts these estimates. The conditions under which DIF cancellation would exist when using the Rasch model are suggested and a proof is provided to support this suggestion. Empirical examples are provided to refute prior suggestions that DIF cancellation always exists if the Rasch model is used.

  15. Assessment of upper limb capacity in children with unilateral cerebral palsy: construct validity of a Rasch-reduced Modified House Classification

    NARCIS (Netherlands)

    Geerdink, Yvonne; Lindeboom, Robert; de Wolf, Sander; Steenbergen, Bert; Geurts, Alexander C. H.; Aarts, Pauline

    2014-01-01

    The aim of this study was to test and improve the unidimensionality and item hierarchy of the Modified House Classification (MHC) for the assessment of upper limb capacity in children with unilateral cerebral palsy (CP) using Rasch analysis. The construct validity of the Rasch-reduced item set was

  16. Scale construction utilising the Rasch unidimensional measurement model: A measurement of adolescent attitudes towards abortion.

    Science.gov (United States)

    Hendriks, Jacqueline; Fyfe, Sue; Styles, Irene; Skinner, S Rachel; Merriman, Gareth

    2012-01-01

    Measurement scales seeking to quantify latent traits like attitudes, are often developed using traditional psychometric approaches. Application of the Rasch unidimensional measurement model may complement or replace these techniques, as the model can be used to construct scales and check their psychometric properties. If data fit the model, then a scale with invariant measurement properties, including interval-level scores, will have been developed. This paper highlights the unique properties of the Rasch model. Items developed to measure adolescent attitudes towards abortion are used to exemplify the process. Ten attitude and intention items relating to abortion were answered by 406 adolescents aged 12 to 19 years, as part of the "Teen Relationships Study". The sampling framework captured a range of sexual and pregnancy experiences. Items were assessed for fit to the Rasch model including checks for Differential Item Functioning (DIF) by gender, sexual experience or pregnancy experience. Rasch analysis of the original dataset initially demonstrated that some items did not fit the model. Rescoring of one item (B5) and removal of another (L31) resulted in fit, as shown by a non-significant item-trait interaction total chi-square and a mean log residual fit statistic for items of -0.05 (SD=1.43). No DIF existed for the revised scale. However, items did not distinguish as well amongst persons with the most intense attitudes as they did for other persons. A person separation index of 0.82 indicated good reliability. Application of the Rasch model produced a valid and reliable scale measuring adolescent attitudes towards abortion, with stable measurement properties. The Rasch process provided an extensive range of diagnostic information concerning item and person fit, enabling changes to be made to scale items. This example shows the value of the Rasch model in developing scales for both social science and health disciplines.

  17. Using the open-source statistical language R to analyze the dichotomous Rasch model.

    Science.gov (United States)

    Li, Yuelin

    2006-08-01

    R, an open-source statistical language and data analysis tool, is gaining popularity among psychologists currently teaching statistics. R is especially suitable for teaching advanced topics, such as fitting the dichotomous Rasch model--a topic that involves transforming complicated mathematical formulas into statistical computations. This article describes R's use as a teaching tool and a data analysis software program in the analysis of the Rasch model in item response theory. It also explains thetheory behind, as well as an educator's goals for, fitting the Rasch model with joint maximum likelihood estimation. This article also summarizes the R syntax for parameter estimation and the calculation of fit statistics. The results produced by R is compared with the results obtained from MINISTEP and the output of a conditional logit model. The use of R is encouraged because it is free, supported by a network of peer researchers, and covers both basic and advanced topics in statistics frequently used by psychologists.

  18. Validation of the Rasch-based Depression Screening in a large scale German general population sample

    Directory of Open Access Journals (Sweden)

    Norra Christine

    2010-09-01

    Full Text Available Abstract Background The study aimed at presenting normative data for both parallel forms of the "Rasch-based Depression Screening (DESC", to examine its Rasch model conformity and convergent and divergent validity based on a representative sample of the German general population. Methods The sample was selected with the assistance of a demographic consulting company applying a face to face interview (N = 2509; mean age = 49.4, SD = 18.2; 55.8% women. Adherence to Rasch model assumptions was determined with analysis of Rasch model fit (infit and outfit, unidimensionality, local independence (principal component factor analysis of the residuals, PCFAR and differential item functioning (DIF with regard to participants' age and gender. Norm values were calculated. Convergent and divergent validity was determined through intercorrelations with the depression and anxiety subscales of the Hospital Anxiety and Depression Scale (HADS-D and HADS-A. Results Fit statistics were below critical values (rDESC-I = .61 and rDESC-II = .60, whereas correlations with HADS-A were rDESC-I = .62 and rDESC-II = .60. Conclusions This study provided further support for the psychometric quality of the DESC. Both forms of the DESC adhered to Rasch model assumptions and showed intercorrelations with HADS subscales that are in line with the literature. The presented normative data offer important advancements for the interpretation of the questionnaire scores and enhance its usefulness for clinical and research applications.

  19. Application of the Rasch model in measuring personality disorders Aplicação do modelo de Rasch na medida de transtornos da personalidade

    Directory of Open Access Journals (Sweden)

    Lucas de Francisco Carvalho

    2012-01-01

    Full Text Available OBJECTIVE: To describe item and person parameters obtained with the Rasch model, one of the item response theory models, in the assessment of personality disorders based on Millon's theory. METHOD: A total of 350 people participated in the study. Age ranged from 18 to 67 years (mean ± standard deviation = 27.02±10.13, and 71.7% of the participants (n = 251 were female. Of the 350 individuals, 21.1% (n = 74 answered affirmatively about being under psychiatric treatment and taking psychiatric medications. The Personality Disorders Dimensional Inventory (PDDI, an instrument designed to assess personality disorders according to Millon's theory, was applied to all participants. Data were analyzed using the Rasch model. RESULTS: Overall, analysis with the Rasch model revealed that the PDDI has adequate psychometric properties for the assessment of personality disorders. CONCLUSION: Among the contributions of item response theory models for clinical instruments, the Rasch person-item map deserves to be highlighted as a successful attempt to improve the understanding of clinical scores obtained in response to particular test items.OBJETIVO: Descrever os parâmetros de itens e pessoas obtidos com o modelo de Rasch, um dos modelos da teoria de resposta ao item, na avaliação de transtornos da personalidade de acordo com a teoria de Millon. MÉTODO: Participaram do estudo 350 pessoas. A idade variou de 18 a 67 anos (média ± desvio padrão = 27.02±10.13, e 71.7% (n = 251 eram do sexo feminino. Dos 350 participantes, 21.1% (n = 74 responderam afirmativamente sobre estarem em tratamento psiquiátrico e utilizarem medicamento psiquiátrico. O Inventário Dimensional de Transtornos da Personalidade (IDTP, destinado à avaliação dos transtornos da personalidade com base na teoria de Millon, foi aplicado a todos os participantes. Os dados foram analisados por meio do modelo de Rasch. RESULTADOS: De modo geral, os resultados da análise por meio do modelo

  20. A log-linear multidimensional Rasch model for capture-recapture.

    Science.gov (United States)

    Pelle, E; Hessen, D J; van der Heijden, P G M

    2016-02-20

    In this paper, a log-linear multidimensional Rasch model is proposed for capture-recapture analysis of registration data. In the model, heterogeneity of capture probabilities is taken into account, and registrations are viewed as dichotomously scored indicators of one or more latent variables that can account for correlations among registrations. It is shown how the probability of a generic capture profile is expressed under the log-linear multidimensional Rasch model and how the parameters of the traditional log-linear model are derived from those of the log-linear multidimensional Rasch model. Finally, an application of the model to neural tube defects data is presented. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Rasch scaling of the Oswestry Disability Index and the Roland-Morris Disability Questionnaire

    DEFF Research Database (Denmark)

    Lauridsen, Henrik Hein; Hartvigsen, Jan

    Title Rasch scaling of the Oswestry Disability Index and the Roland-Morris Disability Index Authors & Affiliations: Henrik Hein Lauridsen1, Jan Hartvigsen1,2 1. Research Unit for Clinical Biomechanics, Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Clinical...... Questionnaire (RMQ) and the Oswestry Disability Index (ODI), however, only few studies have tested these questionnaires using Rasch analysis. This study used Rasch scaling to test the construct validity of the Danish versions of the RMQ (23-item Patrick version) and the ODI (version 2.1a) in a heterogeneous...... on an ordinal scale into interval scaling in addition to optimising the fit of instrument items to the target population. In low back pain research the two most commonly used and well-validated questionnaires to assess functional status in patients with low back pain are the Roland-Morris Disability...

  2. Assessing and quantifying inter-rater variation for dichotomous ratings using a Rasch model

    DEFF Research Database (Denmark)

    Petersen, Jørgen Holm; Larsen, Klaus; Kreiner, Svend

    2010-01-01

    We present a new model-based approach to the analysis of agreement between raters in a situation where all raters have supplied dichotomous ratings of the same cases in a sample. The model is a logistic regression model with random effects - a Rasch model. In the rater setting, the Rasch model...... includes parameters that allow raters to have different propensities to score a given set of individuals positively or negatively - the rater bias. An exact score test of the hypothesis of no rater bias is proposed and is shown to be an exact generalised McNemar's test. Based on the model, we suggest...

  3. The effect of increasingly stringent diagnostic criteria on sex ...

    African Journals Online (AJOL)

    Sex differences in premorbid function and symptomatology were examined as increasingly stringent criteria for schizophrenia were applied to 182 male and 139 female . psychotic patients. The male/female ratio rose from 1.6 among those meeting the CATEGO 'broad' criteria for schizophrenia to 3.7 among those satisfying ...

  4. Circuitry linking the Csr and stringent response global regulatory systems.

    Science.gov (United States)

    Edwards, Adrianne N; Patterson-Fortin, Laura M; Vakulskas, Christopher A; Mercante, Jeffrey W; Potrykus, Katarzyna; Vinella, Daniel; Camacho, Martha I; Fields, Joshua A; Thompson, Stuart A; Georgellis, Dimitris; Cashel, Michael; Babitzke, Paul; Romeo, Tony

    2011-06-01

    CsrA protein regulates important cellular processes by binding to target mRNAs and altering their translation and/or stability. In Escherichia coli, CsrA binds to sRNAs, CsrB and CsrC, which sequester CsrA and antagonize its activity. Here, mRNAs for relA, spoT and dksA of the stringent response system were found among 721 different transcripts that copurified with CsrA. Many of the transcripts that copurified with CsrA were previously determined to respond to ppGpp and/or DksA. We examined multiple regulatory interactions between the Csr and stringent response systems. Most importantly, DksA and ppGpp robustly activated csrB/C transcription (10-fold), while they modestly activated csrA expression. We propose that CsrA-mediated regulation is relieved during the stringent response. Gel shift assays confirmed high affinity binding of CsrA to relA mRNA leader and weaker interactions with dksA and spoT. Reporter fusions, qRT-PCR and immunoblotting showed that CsrA repressed relA expression, and (p)ppGpp accumulation during stringent response was enhanced in a csrA mutant. CsrA had modest to negligible effects on dksA and spoT expression. Transcription of dksA was negatively autoregulated via a feedback loop that tended to mask CsrA effects. We propose that the Csr system fine-tunes the stringent response and discuss biological implications of the composite circuitry. © Published 2011. This article is a US Government work and is in the public domain in the USA.

  5. Item Information in the Rasch Model

    NARCIS (Netherlands)

    Engelen, Ron J.H.; van der Linden, Willem J.; Oosterloo, Sebe J.

    1988-01-01

    Fisher's information measure for the item difficulty parameter in the Rasch model and its marginal and conditional formulations are investigated. It is shown that expected item information in the unconditional model equals information in the marginal model, provided the assumption of sampling

  6. Fitting polytomous Rasch models in SAS

    DEFF Research Database (Denmark)

    Christensen, Karl Bang

    2006-01-01

    The item parameters of a polytomous Rasch model can be estimated using marginal and conditional approaches. This paper describes how this can be done in SAS (V8.2) for three item parameter estimation procedures: marginal maximum likelihood estimation, conditional maximum likelihood estimation, an...

  7. Rasch Model Applications To Determine the Equivalence of a Readiness Test in Two Languages.

    Science.gov (United States)

    Lang, William Steve; And Others

    The Lollipop Test (La Prueba Lollipop) is a bilingual preschool readiness test (in both English and Spanish) that has been the subject of a number of studies to assess validity and detect cultural bias. Such studies have not dealt with item analysis as a way to measure cultural fairness. The Rasch model was used in a study of the Lollipop test…

  8. Construct validation and the Rasch model: functional ability of healthy elderly people

    DEFF Research Database (Denmark)

    Avlund, K; Kreiner, S; Schultz-Larsen, K

    1993-01-01

    in the county of Copenhagen. Functional ability was measured with the traditional activities of daily living and with a classification system developed specially for healthy elderly people. Construct validity was tested by the Rasch model for item analysis, addressing specifically the internal validity...

  9. An investigation of Mathematical Literacy assessment supported by an application of Rasch measurement

    Directory of Open Access Journals (Sweden)

    Caroline Long

    2014-05-01

    Full Text Available Mathematical Literacy (ML is a relatively new school subject that learners study in the final 3 years of high school and is examined as a matric subject. An investigation of a 2009 provincial examination written by matric pupils was conducted on both the curriculum elements of the test and learner performance. In this study we supplement the prior qualitative investigation with an application of Rasch measurement theory to review and revise the scoring procedures so as to better reflect scoring intentions. In an application of the Rasch model, checks are made on the test as a whole, the items and the learner responses, to ensure coherence of the instrument for the particular reference group, in this case Mathematical Literacy learners in one high school. In this article, we focus on the scoring of polytomous items, that is, items that are scored 0, 1, 2 … m. We found in some instances indiscriminate mark allocations, which contravened assessment and measurement principles. Through the investigation of each item, the associated scoring logic and the output of the Rasch analysis, rescoring was explored. We report here on the analysis of the test prior to rescoring, the analysis and rescoring of individual items and the post rescore analysis. The purpose of the article is to address the question: How may detailed attention to the scoring of the items in a Mathematical Literacy test, through theoretical investigation and the application of the Rasch model, contribute to a more informative and coherent outcome?

  10. Is ionizing radiation regulated more stringently than chemical carcinogens

    International Nuclear Information System (INIS)

    Travis, C.C.; Pack, S.R.; Hattemer-Frey, H.A.

    1989-01-01

    It is widely believed that United States government agencies regulate exposure to ionizing radiation more stringently than exposure to chemical carcinogens. It is difficult to verify this perception, however, because chemical carcinogens and ionizing radiation are regulated using vastly different strategies. Chemical carcinogens are generally regulated individually. Regulators consider the risk of exposure to one chemical rather than the cumulative radiation exposure from all sources. Moreover, standards for chemical carcinogens are generally set in terms of quantities released or resultant environmental concentrations, while standards for ionizing radiation are set in terms of dose to the human body. Since chemicals and ionizing radiation cannot be compared on the basis of equal dose to the exposed individual, standards regulating chemicals and ionizing radiation cannot be compared directly. It is feasible, however, to compare the two sets of standards on the basis of equal risk to the exposed individual, assuming that standards for chemicals and ionizing radiation are equivalent if estimated risk levels are equitable. This paper compares risk levels associated with current standards for ionizing radiation and chemical carcinogens. The authors do not attempt to determine whether either type of risk is regulated too stringently or not stringently enough but endeavor only to ascertain if ionizing radiation is actually regulated more strictly than chemical carcinogens

  11. Psychometric assessment of HIV/STI sexual risk scale among MSM: A Rasch model approach

    Directory of Open Access Journals (Sweden)

    Liu Hui

    2011-10-01

    Full Text Available Abstract Background Little research has assessed the degree of severity and ordering of different types of sexual behaviors for HIV/STI infection in a measurement scale. The purpose of this study was to apply the Rasch model on psychometric assessment of an HIV/STI sexual risk scale among men who have sex with men (MSM. Methods A cross-sectional study using respondent driven sampling was conducted among 351 MSM in Shenzhen, China. The Rasch model was used to examine the psychometric properties of an HIV/STI sexual risk scale including nine types of sexual behaviors. Results The Rasch analysis of the nine items met the unidimensionality and local independence assumption. Although the person reliability was low at 0.35, the item reliability was high at 0.99. The fit statistics provided acceptable infit and outfit values. Item difficulty invariance analysis showed that the item estimates of the risk behavior items were invariant (within error. Conclusions The findings suggest that the Rasch model can be utilized for measuring the level of sexual risk for HIV/STI infection as a single latent construct and for establishing the relative degree of severity of each type of sexual behavior in HIV/STI transmission and acquisition among MSM. The measurement scale provides a useful measurement tool to inform, design and evaluate behavioral interventions for HIV/STI infection among MSM.

  12. Flight Hardware Packaging Design for Stringent EMC Radiated Emission Requirements

    Science.gov (United States)

    Lortz, Charlene L.; Huang, Chi-Chien N.; Ravich, Joshua A.; Steiner, Carl N.

    2013-01-01

    This packaging design approach can help heritage hardware meet a flight project's stringent EMC radiated emissions requirement. The approach requires only minor modifications to a hardware's chassis and mainly concentrates on its connector interfaces. The solution is to raise the surface area where the connector is mounted by a few millimeters using a pedestal, and then wrapping with conductive tape from the cable backshell down to the surface-mounted connector. This design approach has been applied to JPL flight project subsystems. The EMC radiated emissions requirements for flight projects can vary from benign to mission critical. If the project's EMC requirements are stringent, the best approach to meet EMC requirements would be to design an EMC control program for the project early on and implement EMC design techniques starting with the circuit board layout. This is the ideal scenario for hardware that is built from scratch. Implementation of EMC radiated emissions mitigation techniques can mature as the design progresses, with minimal impact to the design cycle. The real challenge exists for hardware that is planned to be flown following a built-to-print approach, in which heritage hardware from a past project with a different set of requirements is expected to perform satisfactorily for a new project. With acceptance of heritage, the design would already be established (circuit board layout and components have already been pre-determined), and hence any radiated emissions mitigation techniques would only be applicable at the packaging level. The key is to take a heritage design with its known radiated emissions spectrum and repackage, or modify its chassis design so that it would have a better chance of meeting the new project s radiated emissions requirements.

  13. Comparison of urine iodine/creatinine ratio between patients following stringent and less stringent low iodine diet for radioiodine remnant ablation of thyroid cancer

    International Nuclear Information System (INIS)

    Roh, Jee Ho; Kim, Byung Il; Ha, Ji Su; Chang, Sei Joong; Shin, Hye Young; Choi, Joon Hyuk; Kim, Do Min; Kim, Chong Soon

    2006-01-01

    A low iodine diet (LID) for 1 ∼ 2 weeks is recommended for patients who undergoing radioiodine remnant ablation. However, the LID educations for patients are different among centers because there is no concrete recommendation for protocol of LID. In this investigation, we compared two representative types of LID protocols performed in several centers in Korea using urine iodine to creatinine tatio (urine I/Cr). From 2006, April to June, patients referred to our center for radioiodine remnant ablation of thyroid cancer from several local hospitals which had different LID protocols were included. We divided into two groups, stringent LID for 1 week and less stringent LID for 2 weeks, then measured their urine I/Cr ratio with spot urine when patients were admitted to the hospital. Total 27 patients were included in this investigation (M:F = 1:26; 13 in one-week stringent LID; 14 in two-week less stringent LID). Average of urine I/Cr ratio was 127.87 ± 78.52 μ g/g in stringent LID for 1 week, and 289.75 ± 188.24 μ g/g in less stringent LID for 2 weeks. It was significantly lower in stringent LID for 1 week group (ρ = 0.008). The number of patients whose urine I/Cr ratios were below 100 μ g/g was 6 of 13 in stringent LID for 1 week group, and 3 of 14 in less stringent LID for 2 weeks group. Stringent LID for 1 week resulted in better urinary I/Cr ratio in our investigation compared with the other protocol. However it still resulted in plenty of inadequate range of I/Cr ratio, so more stringent protocol such as stringent LID for 2 weeks is expected more desirable

  14. A gentle introduction to Rasch measurement models for metrologists

    International Nuclear Information System (INIS)

    Mari, Luca; Wilson, Mark

    2013-01-01

    The talk introduces the basics of Rasch models by systematically interpreting them in the conceptual and lexical framework of the International Vocabulary of Metrology, third edition (VIM3). An admittedly simple example of physical measurement highlights the analogies between physical transducers and tests, as they can be understood as measuring instruments of Rasch models and psychometrics in general. From the talk natural scientists and engineers might learn something of Rasch models, as a specifically relevant case of social measurement, and social scientists might re-interpret something of their knowledge of measurement in the light of the current physical measurement models

  15. A Rasch Rating Scale Modeling of the Schutte Self-Report Emotional Intelligence Scale in a Sample of International Students

    Science.gov (United States)

    Kim, Do-Hong; Wang, Chuang; Ng, Kok-Mun

    2010-01-01

    This study examined the psychometric properties of the Schutte Self-Report Emotional Intelligence (SSREI) scale in a sample of international students studying in the U.S. universities using Rasch analysis. The results indicated that the original five-category rating structure may not function effectively for the international student sample. The…

  16. Scale construction utilising the Rasch unidimensional measurement model: A measurement of adolescent attitudes towards abortion

    Directory of Open Access Journals (Sweden)

    Jacqueline Hendriks

    2012-05-01

    Full Text Available BackgroundMeasurement scales seeking to quantify latent traits likeattitudes, are often developed using traditionalpsychometric approaches. Application of the Raschunidimensional measurement model may complement orreplace these techniques, as the model can be used toconstruct scales and check their psychometric properties. Ifdata fit the model, then a scale with invariant measurementproperties, including interval-level scores, will have beendeveloped.AimsThis paper highlights the unique properties of the Raschmodel. Items developed to measure adolescent attitudestowards abortion are used to exemplify the process.MethodTen attitude and intention items relating to abortion wereanswered by 406 adolescents aged 12 to 19 years, as part ofthe “Teen Relationships Study”. The sampling frameworkcaptured a range of sexual and pregnancy experiences.Items were assessed for fit to the Rasch model includingchecks for Differential Item Functioning (DIF by gender,sexual experience or pregnancy experience.ResultsRasch analysis of the original dataset initially demonstratedthat some items did not fit the model. Rescoring of one item(B5 and removal of another (L31 resulted in fit, as shownby a non-significant item-trait interaction total chi-squareand a mean log residual fit statistic for items of -0.05(SD=1.43. No DIF existed for the revised scale. However,items did not distinguish as well amongst persons with themost intense attitudes as they did for other persons. Aperson separation index of 0.82 indicated good reliability.ConclusionApplication of the Rasch model produced a valid andreliable scale measuring adolescent attitudes towardsabortion, with stable measurement properties. The Raschprocess provided an extensive range of diagnosticinformation concerning item and person fit, enablingchanges to be made to scale items. This example shows thevalue of the Rasch model in developing scales for bothsocial science and health disciplines.

  17. Psychometric validation of the Persian Bergen Social Media Addiction Scale using classic test theory and Rasch models.

    Science.gov (United States)

    Lin, Chung-Ying; Broström, Anders; Nilsen, Per; Griffiths, Mark D; Pakpour, Amir H

    2017-12-01

    Background and aims The Bergen Social Media Addiction Scale (BSMAS), a six-item self-report scale that is a brief and effective psychometric instrument for assessing at-risk social media addiction on the Internet. However, its psychometric properties in Persian have never been examined and no studies have applied Rasch analysis for the psychometric testing. This study aimed to verify the construct validity of the Persian BSMAS using confirmatory factor analysis (CFA) and Rasch models among 2,676 Iranian adolescents. Methods In addition to construct validity, measurement invariance in CFA and differential item functioning (DIF) in Rasch analysis across gender were tested for in the Persian BSMAS. Results Both CFA [comparative fit index (CFI) = 0.993; Tucker-Lewis index (TLI) = 0.989; root mean square error of approximation (RMSEA) = 0.057; standardized root mean square residual (SRMR) = 0.039] and Rasch (infit MnSq = 0.88-1.28; outfit MnSq = 0.86-1.22) confirmed the unidimensionality of the BSMAS. Moreover, measurement invariance was supported in multigroup CFA including metric invariance (ΔCFI = -0.001; ΔSRMR = 0.003; ΔRMSEA = -0.005) and scalar invariance (ΔCFI = -0.002; ΔSRMR = 0.005; ΔRMSEA = 0.001) across gender. No item displayed DIF (DIF contrast = -0.48 to 0.24) in Rasch across gender. Conclusions Given the Persian BSMAS was unidimensional, it is concluded that the instrument can be used to assess how an adolescent is addicted to social media on the Internet. Moreover, users of the instrument may comfortably compare the sum scores of the BSMAS across gender.

  18. Funding Medical Research Projects: Taking into Account Referees' Severity and Consistency through Many-Faceted Rasch Modeling of Projects' Scores.

    Science.gov (United States)

    Tesio, Luigi; Simone, Anna; Grzeda, Mariuzs T; Ponzio, Michela; Dati, Gabriele; Zaratin, Paola; Perucca, Laura; Battaglia, Mario A

    2015-01-01

    The funding policy of research projects often relies on scores assigned by a panel of experts (referees). The non-linear nature of raw scores and the severity and inconsistency of individual raters may generate unfair numeric project rankings. Rasch measurement (many-facets version, MFRM) provides a valid alternative to scoring. MFRM was applied to the scores achieved by 75 research projects on multiple sclerosis sent in response to a previous annual call by FISM-Italian Foundation for Multiple Sclerosis. This allowed to simulate, a posteriori, the impact of MFRM on the funding scenario. The applications were each scored by 2 to 4 independent referees (total = 131) on a 10-item, 0-3 rating scale called FISM-ProQual-P. The rotation plan assured "connection" of all pairs of projects through at least 1 shared referee.The questionnaire fulfilled satisfactorily the stringent criteria of Rasch measurement for psychometric quality (unidimensionality, reliability and data-model fit). Arbitrarily, 2 acceptability thresholds were set at a raw score of 21/30 and at the equivalent Rasch measure of 61.5/100, respectively. When the cut-off was switched from score to measure 8 out of 18 acceptable projects had to be rejected, while 15 rejected projects became eligible for funding. Some referees, of various severity, were grossly inconsistent (z-std fit indexes less than -1.9 or greater than 1.9). The FISM-ProQual-P questionnaire seems a valid and reliable scale. MFRM may help the decision-making process for allocating funds to MS research projects but also in other fields. In repeated assessment exercises it can help the selection of reliable referees. Their severity can be steadily calibrated, thus obviating the need to connect them with other referees assessing the same projects.

  19. An evaluation of the structural validity of the shoulder pain and disability index (SPADI) using the Rasch model.

    Science.gov (United States)

    Jerosch-Herold, Christina; Chester, Rachel; Shepstone, Lee; Vincent, Joshua I; MacDermid, Joy C

    2018-02-01

    The shoulder pain and disability index (SPADI) has been extensively evaluated for its psychometric properties using classical test theory (CTT). The purpose of this study was to evaluate its structural validity using Rasch model analysis. Responses to the SPADI from 1030 patients referred for physiotherapy with shoulder pain and enrolled in a prospective cohort study were available for Rasch model analysis. Overall fit, individual person and item fit, response format, dependence, unidimensionality, targeting, reliability and differential item functioning (DIF) were examined. The SPADI pain subscale initially demonstrated a misfit due to DIF by age and gender. After iterative analysis it showed good fit to the Rasch model with acceptable targeting and unidimensionality (overall fit Chi-square statistic 57.2, p = 0.1; mean item fit residual 0.19 (1.5) and mean person fit residual 0.44 (1.1); person separation index (PSI) of 0.83. The disability subscale however shows significant misfit due to uniform DIF even after iterative analyses were used to explore different solutions to the sources of misfit (overall fit (Chi-square statistic 57.2, p = 0.1); mean item fit residual 0.54 (1.26) and mean person fit residual 0.38 (1.0); PSI 0.84). Rasch Model analysis of the SPADI has identified some strengths and limitations not previously observed using CTT methods. The SPADI should be treated as two separate subscales. The SPADI is a widely used outcome measure in clinical practice and research; however, the scores derived from it must be interpreted with caution. The pain subscale fits the Rasch model expectations well. The disability subscale does not fit the Rasch model and its current format does not meet the criteria for true interval-level measurement required for use as a primary endpoint in clinical trials. Clinicians should therefore exercise caution when interpreting score changes on the disability subscale and attempt to compare their scores to age- and sex

  20. Development of Rasch-based item banks for the assessment of work performance in patients with musculoskeletal diseases.

    Science.gov (United States)

    Mueller, Evelyn A; Bengel, Juergen; Wirtz, Markus A

    2013-12-01

    This study aimed to develop a self-description assessment instrument to measure work performance in patients with musculoskeletal diseases. In terms of the International Classification of Functioning, Disability and Health (ICF), work performance is defined as the degree of meeting the work demands (activities) at the actual workplace (environment). To account for the fact that work performance depends on the work demands of the job, we strived to develop item banks that allow a flexible use of item subgroups depending on the specific work demands of the patients' jobs. Item development included the collection of work tasks from literature and content validation through expert surveys and patient interviews. The resulting 122 items were answered by 621 patients with musculoskeletal diseases. Exploratory factor analysis to ascertain dimensionality and Rasch analysis (partial credit model) for each of the resulting dimensions were performed. Exploratory factor analysis resulted in four dimensions, and subsequent Rasch analysis led to the following item banks: 'impaired productivity' (15 items), 'impaired cognitive performance' (18), 'impaired coping with stress' (13) and 'impaired physical performance' (low physical workload 20 items, high physical workload 10 items). The item banks exhibited person separation indices (reliability) between 0.89 and 0.96. The assessment of work performance adds the activities component to the more commonly employed participation component of the ICF-model. The four item banks can be adapted to specific jobs where necessary without losing comparability of person measures, as the item banks are based on Rasch analysis.

  1. On designing data-sampling for Rasch model calibrating an achievement test

    Directory of Open Access Journals (Sweden)

    TAKUYA YANAGIDA

    2009-12-01

    Full Text Available In correspondence with pertinent statistical tests, it is of practical importance to design data-sampling when the Rasch model is used for calibrating an achievement test. That is, determining the sample size according to a given type-I- and type-II-risk, and according to a certain effect of model misfit which is of practical relevance is of interest. However, pertinent Rasch model tests use chi-squared distributed test-statistics, whose degrees of freedom do not depend on the sample size or the number of testees, but only on the number of estimated parameters. We therefore suggest a new approach using an F-distributed statistic as applied within analysis of variance, where the sample size directly affects the degrees of freedom. The Rasch model’s quality of specific objective measurement is in accordance with no interaction effect in a specific analysis of variance design. In analogy to Andersen’s approach in his Likelihood-Ratio test, the testees must be divided into at least two groups according to some criterion suspected of causing differential item functioning (DIF. Then a three-way analysis of variance design (A>BxC with mixed classification is the result: There is a (fixed group factor A, a (random factor B of testees within A, and a (fixed factor C of items cross-classified with A>B; obviously the factor B is nested within A. Yet the data are dichotomous (a testee either solves an item or fails to solve it and only one observation per cell exists. The latter is not assumed to do harm, though the design is a mixed classification. But the former suggests the need to perform a simulation study in order to test whether the type-I-risk holds for the AxC interaction F-test – this interaction effect corresponds to Rasch model’s specific objectivity. If so, the critical number of testees is of interest for fulfilling the pertinent precision parameters. The simulation study (100 000 runs for each of several special cases proved that the

  2. Quality of life for post-polio syndrome: a patient derived, Rasch standard scale.

    Science.gov (United States)

    Young, Carolyn A; Quincey, Anne-Marie C; Wong, Samantha M; Tennant, Alan

    2018-03-01

    To design a disease-specific quality of life (QoL) questionnaire for people with post-polio syndrome (PPS). Qualitative interviews were conducted with 45 people with PPS to identify themes and derive potential items reflecting impact upon QoL. After cognitive debriefing, these were made into a questionnaire pack along with comparative questionnaires and posted to 319 patients. The 271 (85%) returned questionnaires were subjected to exploratory factor analysis (EFA) and Rasch analysis. A 25 item scale, the post-polio quality of life scale (PP-QoL), showed good fit to the Rasch model (conditional chi-square p = 0.156), unidimensionality (% t-tests 2.0: CI 0.7-3.8), and Cronbach's alpha of 0.87. With the latent estimate transformed to a 0-100 scale, the mean score was 56.9 (SD 18.5) with only 3.3% of respondents at the floor or ceiling of the scale. Test-retest reliability showed an intraclass correlation coefficient (ICC) (2.1) of 0.916, and correlation of 0.85. The disease-specific PP-QoL demonstrated excellent reliability, appropriate concurrent validity, and satisfied the standards of the Rasch model. It enables examination of the impact of health status upon perceived QoL, and the impact of rehabilitation interventions. The scale is freely available for academic or not-for-profit users to improve research in this neglected, disabling condition. Implications for Rehabilitation In post-polio syndrome (PPS), existing work examines aspects of health-related quality of life (HRQoL), such as activity limitations. A disease-specific QoL measure would enable researchers to model the impact of health status, such as fatigue or mobility restrictions, upon QoL in PPS. The post-polio quality of life scale (PP-QoL) is based on the patients' lived experience, meets Rasch standards and is free for use for academic and not-for-profit researchers. The raw score is reliable for individual use in clinical settings, and interval scale transformation is available for parametric

  3. Air Quality and Health Benefits of China's Recent Stringent Environmental Policy

    Science.gov (United States)

    Zheng, Y.; Xue, T.; Zhang, Q.; Geng, G.; He, K.

    2016-12-01

    Aggressive emission control measures were taken by China's central and local governments after the promulgation of the "Air Pollution Prevention and Control Action Plan" in 2013. We evaluated the air quality and health benefits of this ever most stringent air pollution control policy during 2013-2015 by utilizing a two-stage data fusion model and newly-developed cause-specific integrated exposure-response functions (IER) developed for the Global Burden of Disease (GBD). The two-stage data fusion model predicts spatiotemporal continuous PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm) concentrations by integrating satellite-derived aerosol optical depth (AOD) measurements, PM2.5 concentrations from measurement and air quality model, and other ancillary information. During the years of analysis, PM2.5 concentration dropped significantly on national average and over heavily polluted regions as identified by Mann-Kendall analysis. The national PM2.5-attributable mortality decreased by 72.8 (95% CI: 59.4, 85.2) thousand (6%) from 1.23 (95% CI: 1.06, 1.39) million in 2013 to 1.15 (95% CI: 0.98, 1.31) million in 2015 due to considerable reduction (i.e. 18%) of population-weighted PM2.5 from 61.4 to 50.5 µg/m3. Meteorological variations between 2013 and 2015 were estimated to raise the PM2.5 levels by 0.24 µg/m3 and national mortality by 2.1 (95% CI: 1.6, 2.6) thousand through sensitivity tests, which implies the dominant role of anthropogenic impacts on PM2.5 abatement and attributable mortality reduction. Our study affirms the effectiveness of China's recent air quality policy, however, due to the possible supralinear shape of C-R functions, health benefits induced by air quality improvement in these years are limited. We therefore appeal for continuous implementation of current policies and further stringent measures from both air quality improvement and public health protection perspectives.

  4. Rasch Calibration of Perceived Weights of Different Sports Games

    Science.gov (United States)

    Kang, Sang-Jo; Kang, Minsoo

    2006-01-01

    In many countries, an athlete's performance at sporting competitions is often used as part of the selection criteria for entry into college. These criteria could be biased depending upon the procedures utilized by the authorities in a particular country. The purpose of this study was to calibrate, by using the Rasch rating scale model, the…

  5. Rasch's model for reading speed with manifest explanatory variables

    NARCIS (Netherlands)

    Jansen, G.G.H.

    In educational and psychological measurement we find the distinction between speed and power tests. Although most tests are partially speeded, the speed element is usually neglected. Here we consider a latent trait model developed by Rasch for the response time on a (set of) pure speed test(s),

  6. Relationships between the Thurstone and Rasch Approaches to Item Scaling.

    Science.gov (United States)

    Andrich, David

    1978-01-01

    When the logistic function is substituted for the normal, Thurstone's Case V specialization of the law of comparative judgment for paired comparison responses gives an identical equation for the estimation of item scale values, as does the Rasch formulation for direct responses. Comparisons are made. (Author/CTM)

  7. Development and validation of the Brazilian version of the Attitudes to Aging Questionnaire (AAQ: An example of merging classical psychometric theory and the Rasch measurement model

    Directory of Open Access Journals (Sweden)

    Trentini Clarissa M

    2008-01-01

    Full Text Available Abstract Background Aging has determined a demographic shift in the world, which is considered a major societal achievement, and a challenge. Aging is primarily a subjective experience, shaped by factors such as gender and culture. There is a lack of instruments to assess attitudes to aging adequately. In addition, there is no instrument developed or validated in developing region contexts, so that the particularities of ageing in these areas are not included in the measures available. This paper aims to develop and validate a reliable attitude to aging instrument by combining classical psychometric approach and Rasch analysis. Methods Pilot study and field trial are described in details. Statistical analysis included classic psychometric theory (EFA and CFA and Rasch measurement model. The latter was applied to examine unidimensionality, response scale and item fit. Results Sample was composed of 424 Brazilian old adults, which was compared to an international sample (n = 5238. The final instrument shows excellent psychometric performance (discriminant validity, confirmatory factor analysis and Rasch fit statistics. Rasch analysis indicated that modifications in the response scale and item deletions improved the initial solution derived from the classic approach. Conclusion The combination of classic and modern psychometric theories in a complementary way is fruitful for development and validation of instruments. The construction of a reliable Brazilian Attitudes to Aging Questionnaire is important for assessing cultural specificities of aging in a transcultural perspective and can be applied in international cross-cultural investigations running less risk of cultural bias.

  8. Cross-cultural adaptation and analysis of the psychometric properties of the Balance Evaluation Systems Test and MiniBESTest in the elderly and individuals with Parkinson's disease: application of the Rasch model

    Directory of Open Access Journals (Sweden)

    Angelica C. Maia

    2013-06-01

    Full Text Available BACKGROUND: Older adults and individuals with neurological problems such as Parkinson's disease (PD exhibit balance deficits that might impair their mobility and independence. The assessment of balance must be useful in identifying the presence of instability and orient interventions. OBJECTIVE: To translate and perform a cross-cultural adaptation of the Balance Evaluation Systems Test (BESTest and MiniBESTest to Brazilian Portuguese and analyze its psychometric properties. METHOD: The tests were translated and adapted to Portuguese according to a standard method and then subjected to a test-retest reliability assessment (10 older adults; 10 individuals with PD. The psychometric properties were assessed by the Rasch model (35 older adults; 35 individuals with PD. RESULTS: The reliability coefficient of the tests relative to the items and subjects varied from 0.91 and 0.98, which is indicative of the stability and reproducibility of the measures. In the BESTest, the person (4.19 and item (5.36 separation index established six balance ability levels and seven levels of difficulty, respectively. In the MiniBESTest, the person (3.16 and item (6.41 separation index established four balance ability levels and nine levels of difficulty, respectively. Two items in the BESTest did not fit with the model expectations, but the construct validity was not compromised. No item in the MiniBESTest was erratic. CONCLUSIONS: The results corroborate the diagnostic and screening functions of the BESTest and MiniBESTest, respectively, and indicate that the Brazilian versions exhibit adequate reliability, construct validity, response stability, and capacity to distinguish among various balance ability levels in older adults and individuals with PD.

  9. Emission reductions in transition economies: A result of output contraction or more stringent environmental policy?

    Energy Technology Data Exchange (ETDEWEB)

    Zugravu, N.; Millock, K. [University Paris 1 Pantheon-Sorbonne (France); Duchene, G. [University Paris 12, Creteil (France)

    2007-07-01

    Countries in Central and Eastern Europe significantly reduced their CO{sub 2} emissions between 1996 and 2001. Was this emission reduction just the fortuitous result of the major economic transformation undergone by those countries in the transition away from a centralized plan economy? Or is the emission reduction rather a result of more stringent environmental policy? The objective of the article is to answer this question through a model of the relation between environmental quality and enforcement, on the one hand, and environmental quality and economic growth, on the other hand. The authors develop structural equations for the demand (emissions) and supply (environmental stringency) of pollution. The supply equation takes into account the institutional quality of the country (control of corruption and political stability) as well as consumer preferences for environmental quality, as proxied by per capita revenue and unemployment. The system is estimated by three stage least squares on a sample of three groups of countries for comparative analysis: Central and Eastern European countries, Western European countries, and emerging economies. The results indicate that, all else equal, the scale effect on its own would have increased industrial CO{sub 2} emissions in the Central and Eastern European countries in the sample by 44.6% between 1996 and 2001. The composition effect accounted for a corresponding reduction in emissions by 16%. The technique effect had the largest marginal impact, corresponding to a 37.4% reduction in emissions.

  10. Rasch measurement properties of the Pain Medication Questionnaire in persons with spinal cord injury.

    Science.gov (United States)

    Hand, B N; Velozo, C A; Krause, J S

    2017-08-01

    Secondary analysis of cross-sectional population-based self-report data. To determine how well the Pain Medication Questionnaire (PMQ) measures risk of pain medication misuse and its precision in separating individuals with spinal cord injury (SCI) into meaningful classification categories. Academic medical center in Southeastern United States. Data were collected from a population-based registry of SCI (n=971). Eligible participants included adults with traumatic SCI with residual effects who were at least 1 year post injury and 18 years of age and who had PMQ data in which they reported active use of pain medication at the time of the study (n=745). Most items (23/26) of the PMQ contributed to a single unidimensional construct. Rasch analysis results revealed that the rating scale, majority of persons (>93%), and majority of items (20/23) fit the Rasch measurement model. The PMQ demonstrated adequate reliability (person reliability =0.67) and separated persons into two strata-those likely to misuse pain medication and those with low liklihood of misusing pain medication. Findings offer a deeper understanding of the measurement properties of the PMQ as a precursor for widespread population-based studies to elucidate the incidence of pain medication misuse in persons with SCI. Results also have important research and clinical implications for commonly used PMQ total score cut-offs, which may misclassify an individual's risk of pain medication misuse.Spinal Cord advance online publication, 1 August 2017; doi:10.1038/sc.2017.89.

  11. Establishing score equivalence of the Functional Independence Measure motor scale and the Barthel Index, utilising the International Classification of Functioning, Disability and Health and Rasch measurement theory.

    Science.gov (United States)

    Prodinger, Birgit; O'Connor, Rory J; Stucki, Gerold; Tennant, Alan

    2017-05-16

    Two widely used outcome measures to assess functioning in neurological rehabilitation are the Functional Independence Measure (FIM™) and the Barthel Index. The current study aims to establish the equivalence of the total score of the FIM™ motor scale and the Barthel Index through the application of the International Classification of Functioning, Disability and Health, and Rasch measurement theory. Secondary analysis of a large sample of patients with stroke, spinal cord injury, and multiple sclerosis, undergoing rehabilitation was conducted. All patients were assessed at the same time on both the FIM™ and the Barthel Index. The International Classification of Functioning, Disability and Health Linking Rules were used to establish conceptual coherency between the 2 scales, and the Rasch measurement model to establish an exchange of the total scores. Using the FIM™ motor scale, items from both scales linked to the International Classification of Functioning, Disability and Health d4 Mobility or d5 Self-care chapters. Their co-calibration satisfied the assumptions of the Rasch model for each of 3 diagnostic groups. A ceiling effect was observed for the Barthel Index when contrasted against the FIM™ motor scale. Having a Rasch interval metric to transform scores between the FIM™ motor scale and Barthel Index is valuable for monitoring functioning, meta-analysis, quality audits and hospital benchmarking.

  12. Identifying potential misfit items in cognitive process of learning engineering mathematics based on Rasch model

    Science.gov (United States)

    Ataei, Sh; Mahmud, Z.; Khalid, M. N.

    2014-04-01

    The students learning outcomes clarify what students should know and be able to demonstrate after completing their course. So, one of the issues on the process of teaching and learning is how to assess students' learning. This paper describes an application of the dichotomous Rasch measurement model in measuring the cognitive process of engineering students' learning of mathematics. This study provides insights into the perspective of 54 engineering students' cognitive ability in learning Calculus III based on Bloom's Taxonomy on 31 items. The results denote that some of the examination questions are either too difficult or too easy for the majority of the students. This analysis yields FIT statistics which are able to identify if there is data departure from the Rasch theoretical model. The study has identified some potential misfit items based on the measurement of ZSTD where the removal misfit item was accomplished based on the MNSQ outfit of above 1.3 or less than 0.7 logit. Therefore, it is recommended that these items be reviewed or revised to better match the range of students' ability in the respective course.

  13. Identifying potential misfit items in cognitive process of learning engineering mathematics based on Rasch model

    International Nuclear Information System (INIS)

    Ataei, Sh; Mahmud, Z; Khalid, M N

    2014-01-01

    The students learning outcomes clarify what students should know and be able to demonstrate after completing their course. So, one of the issues on the process of teaching and learning is how to assess students' learning. This paper describes an application of the dichotomous Rasch measurement model in measuring the cognitive process of engineering students' learning of mathematics. This study provides insights into the perspective of 54 engineering students' cognitive ability in learning Calculus III based on Bloom's Taxonomy on 31 items. The results denote that some of the examination questions are either too difficult or too easy for the majority of the students. This analysis yields FIT statistics which are able to identify if there is data departure from the Rasch theoretical model. The study has identified some potential misfit items based on the measurement of ZSTD where the removal misfit item was accomplished based on the MNSQ outfit of above 1.3 or less than 0.7 logit. Therefore, it is recommended that these items be reviewed or revised to better match the range of students' ability in the respective course.

  14. Rapid Curtailing of the Stringent Response by Toxin-Antitoxin Encoded mRNases

    DEFF Research Database (Denmark)

    Tian, Chengzhe; Roghanian, Mohammad; Jørgensen, Mikkel Girke

    2016-01-01

    Escherichia coli regulates its metabolism to adapt to changes in the environment, in particular to stressful downshifts in nutrient quality. Such shifts elicit the so-called stringent response coordinated by the alarmone guanosine tetra- and pentaphosphate [(p)ppGpp]. At sudden amino-acid (aa......RNase-encoding TA modules present in the wt strain. This observation suggested that toxins are part of the negative feedback to control the (p)ppGpp level during early stringent response. We built a ribosome trafficking model to evaluate the fold of increase in the RelA activity just after the onset of aa...... %. IMPORTANCE: The early stringent response elicited by amino-acid starvation is controlled by a sharp increase of the cellular (p)ppGpp level. Toxin-antitoxin encoded mRNases are activated by (p)ppGpp through enhanced degradation of antitoxins. The present work shows that this activation happens at a very...

  15. Calibration of a Chemistry Test Using the Rasch Model

    Directory of Open Access Journals (Sweden)

    Nancy Coromoto Martín Guaregua

    2011-11-01

    Full Text Available The Rasch model was used to calibrate a general chemistry test for the purpose of analyzing the advantages and information the model provides. The sample was composed of 219 college freshmen. Of the 12 questions used, good fit was achieved in 10. The evaluation shows that although there are items of variable difficulty, there are gaps on the scale; in order to make the test complete, it will be necessary to design new items to fill in these gaps.

  16. The stringent response regulates adaptation to darkness in the cyanobacterium Synechococcus elongatus.

    Science.gov (United States)

    Hood, Rachel D; Higgins, Sean A; Flamholz, Avi; Nichols, Robert J; Savage, David F

    2016-08-16

    The cyanobacterium Synechococcus elongatus relies upon photosynthesis to drive metabolism and growth. During darkness, Synechococcus stops growing, derives energy from its glycogen stores, and greatly decreases rates of macromolecular synthesis via unknown mechanisms. Here, we show that the stringent response, a stress response pathway whose genes are conserved across bacteria and plant plastids, contributes to this dark adaptation. Levels of the stringent response alarmone guanosine 3'-diphosphate 5'-diphosphate (ppGpp) rise after a shift from light to dark, indicating that darkness triggers the same response in cyanobacteria as starvation in heterotrophic bacteria. High levels of ppGpp are sufficient to stop growth and dramatically alter many aspects of cellular physiology, including levels of photosynthetic pigments and polyphosphate, DNA content, and the rate of translation. Cells unable to synthesize ppGpp display pronounced growth defects after exposure to darkness. The stringent response regulates expression of a number of genes in Synechococcus, including ribosomal hibernation promoting factor (hpf), which causes ribosomes to dimerize in the dark and may contribute to decreased translation. Although the metabolism of Synechococcus differentiates it from other model bacterial systems, the logic of the stringent response remains remarkably conserved, while at the same time having adapted to the unique stresses of the photosynthetic lifestyle.

  17. Structural characterization of the stringent response related exopolyphosphatase/guanosine pentaphosphate phosphohydrolase protein family

    DEFF Research Database (Denmark)

    Kristensen, Ole; Laurberg, Martin; Liljas, Anders

    2004-01-01

    Exopolyphosphatase/guanosine pentaphosphate phosphohydrolase (PPX/GPPA) enzymes play central roles in the bacterial stringent response induced by starvation. The high-resolution crystal structure of the putative Aquifex aeolicus PPX/GPPA phosphatase from the actin-like ATPase domain superfamily h...

  18. The Rasch Poisson counts model for incomplete data : An application of the EM algorithm

    NARCIS (Netherlands)

    Jansen, G.G.H.

    Rasch's Poisson counts model is a latent trait model for the situation in which K tests are administered to N examinees and the test score is a count [e.g., the repeated occurrence of some event, such as the number of items completed or the number of items answered (in)correctly]. The Rasch Poisson

  19. On Applications of Rasch Models in International Comparative Large-Scale Assessments: A Historical Review

    Science.gov (United States)

    Wendt, Heike; Bos, Wilfried; Goy, Martin

    2011-01-01

    Several current international comparative large-scale assessments of educational achievement (ICLSA) make use of "Rasch models", to address functions essential for valid cross-cultural comparisons. From a historical perspective, ICLSA and Georg Rasch's "models for measurement" emerged at about the same time, half a century ago. However, the…

  20. A Comparison of Uniform DIF Effect Size Estimators under the MIMIC and Rasch Models

    Science.gov (United States)

    Jin, Ying; Myers, Nicholas D.; Ahn, Soyeon; Penfield, Randall D.

    2013-01-01

    The Rasch model, a member of a larger group of models within item response theory, is widely used in empirical studies. Detection of uniform differential item functioning (DIF) within the Rasch model typically employs null hypothesis testing with a concomitant consideration of effect size (e.g., signed area [SA]). Parametric equivalence between…

  1. Estimating quasi-loglinear models for a Rasch table if the numbers of items is large

    NARCIS (Netherlands)

    Kelderman, Henk

    1987-01-01

    The Rasch Model and various extensions of this model can be formulated as a quasi loglinear model for the incomplete subgroup x score x item response 1 x ... x item response k contingency table. By comparing various loglinear models, specific deviations of the Rasch model can be tested. Parameter

  2. Measuring students' perceptions of plagiarism: modification and Rasch validation of a plagiarism attitude scale.

    Science.gov (United States)

    Howard, Steven J; Ehrich, John F; Walton, Russell

    2014-01-01

    Plagiarism is a significant area of concern in higher education, given university students' high self-reported rates of plagiarism. However, research remains inconsistent in prevalence estimates and suggested precursors of plagiarism. This may be a function of the unclear psychometric properties of the measurement tools adopted. To investigate this, we modified an existing plagiarism scale (to broaden its scope), established its psychometric properties using traditional (EFA, Cronbach's alpha) and modern (Rasch analysis) survey evaluation approaches, and examined results of well-functioning items. Results indicated that traditional and modern psychometric approaches differed in their recommendations. Further, responses indicated that although most respondents acknowledged the seriousness of plagiarism, these attitudes were neither unanimous nor consistent across the range of issues assessed. This study thus provides rigorous psychometric testing of a plagiarism attitude scale and baseline data from which to begin a discussion of contextual, personal, and external factors that influence students' plagiarism attitudes.

  3. Profil Perencanaan Karir Siswa Sekolah Menengah Kejuruan dengan Pemodelan Rasch Berdasarkan Jenis Kelamin

    Directory of Open Access Journals (Sweden)

    Itsar Bolo Rangka

    2017-08-01

    Full Text Available This research aimed to (1 perform inventory career planning of students, and (2 measuring students career planning based on gender. Data analysis used Rasch model for 45 students with actual power measurement 0.9272652. The research findings showed (1 inventory career planning has been fit with the theoretic model, and (2 female student have a tendency to a higher career planning rather than male student. In the future, to measurement of student’s career planning by using this inventory can only produce a high measurement information for students who have a mediocre ability. Further, the researcher need to consider to eliminate item No. 12 in this inventory due to the biased towards the male gender.

  4. Using Rasch models to develop and validate an environmental thinking learning progression

    Science.gov (United States)

    Hashimoto-Martell, Erin A.

    Environmental understanding is highly relevant in today's global society. Social, economic, and political structures are connected to the state of environmental degradation and exploitation, and disproportionately affect those in poor or urban communities (Brulle & Pellow, 2006; Executive Order No. 12898, 1994). Environmental education must challenge the way we live, and our social and ecological quality of life, with the goal of responsible action. The development of a learning progression in environmental thinking, along with a corresponding assessment, could provide a tool that could be used across environmental education programs to help evaluate and guide programmatic decisions. This study sought to determine if a scale could be constructed that allowed individuals to be ordered along a continuum of environmental thinking. First, I developed the Environmental Thinking Learning Progression, a scale of environmental thinking from novice to advanced, based on the current available research and literature. The scale consisted of four subscales, each measuring a different aspect of environmental thinking: place consciousness, human connection, agency, and science concepts. Second, a measurement instrument was developed, so that the data appropriately fit the model using Rasch analysis. A Rasch analysis of the data placed respondents along a continuum, given the range of item difficulty for each subscale. Across three iterations of instrument revision and data collection, findings indicated that the items were ordered in a hierarchical way that corresponded to the construct of environmental thinking. Comparisons between groups showed that the average score of respondents who had participated in environmental education programs was significantly higher than those who had not. A comparison between males and females showed no significant difference in average measure, however, there were varied significant differences between how racial/ethnic groups performed. Overall

  5. Rasch model of the GAIN substance problem scale among Canadian adults seeking residential and outpatient addiction treatment.

    Science.gov (United States)

    Kenaszchuk, Chris; Wild, T Cameron; Rush, Brian R; Urbanoski, Karen

    2013-07-01

    The GAIN Substance Problem Scale (SPS) measures alcohol and drug problem severity within a DSM-IV-TR framework. This study builds on prior psychometric evaluation of the SPS by using Rasch analysis to assess scale unidimensionality, item severity, and differential item functioning (DIF). Participants were attending residential or outpatient treatment in Alberta and Ontario, Canada, respectively (n=372). Rasch analyses modeled a latent problem severity continuum using SPS scores at treatment admission and 6-week follow-up. We examined DIF by gender, treatment modality (outpatient vs. residential), and assessment timing (baseline vs. follow-up). Model fit was good overall, supporting unidimensionality and a single underlying continuum of substance problem severity. Relative to person severity, however, the range of item severities was narrow. Items were too severe for many clients to endorse, particularly at follow-up. Overall, the rank order of item severities was stable across gender, treatment modality, and time point. Although traditional Rasch criteria indicated a number of statistically significant and substantive DIF estimates across modality and time points, effect size indices did not suggest a net effect on total scale scores. The analysis broadly supports use of the SPS as an additive measure of global substance severity in men and women and both residential and outpatient settings. Although DIF was not a major concern, there was evidence of item redundancy and suboptimal matching between items and persons. Findings highlight potential opportunities for further improving this scale in future research and clinical applications of the GAIN. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Validity of the Brazilian version of WHOQOL-BREF in depressed patients using Rasch modelling Validez de la versión brasilera de WHOQOL-BREF en pacientes deprimidos usando el modelo del Rasch Validade da versão brasileira do WHOQOL-BREF em pacientes deprimidos usando o modelo de Rasch

    Directory of Open Access Journals (Sweden)

    Neusa Sica da Rocha

    2009-02-01

    Full Text Available OBJECTIVE: To assess the validity of the Brazilian version of the World Health Organization Quality of Life Instrument - Abbreviated version (WHOQOL-BREF in adults with major depression, using Rasch modelling. METHODS: Study analyzing data from the baseline sample of the Longitudinal Investigation of Depression Outcomes in Brazil, including a total of 208 patients with major depression recruited in a primary care service in Porto Alegre (Southern Brazil, in 1999. The Center for Epidemiological Studies Depression Scale was used to assess intensity of depression; the WHOQOL-BREF to assess generic quality of life; and the Composite International Diagnostic Interview version 2.1 for the diagnosis of depression. RESULTS: In the Rasch analysis, the four domains of WHOQOL-BREF showed appropriate fit to this model. Some items needed adjustments: four items were rescored (pain, finances, services, and transport; two items (work and activity were identified as having dependency of responses, and one item was deleted (sleep due to multidimensionality. CONCLUSIONS: The validation of the WHOQOL-BREF Brazilian version using Rasch analysis complements previous validation studies, evidencing the robustness of this instrument as a generic cross-cultural quality of life measure.OBJETIVO: Evaluar la validez de la version brasilera del Instrumento de Calidad de Vida de la Organización Mundial de la Salud, abreviado en inglés WHOQOL-BREF, en adultos con depression, usando el modelo de Rasch. MÉTODOS: Se analizaron datos de la base de Investigación Longitudinal de Resultados de Depresión en Brasil, incluyendo un total de 208 pacientes con derpesión mayor recluidos en servicio de ciudado primario en Porto Alegre (Sur de Brasil, en 1999. El Centro de Estudios Epidemiológicos de Depresión fue usado para evaluar la intensidad de la depresión; el WHOQOLBREF para evaluar la calidad genérica de vida; y la Entrevista Internacional Compuesta para el Diagnostico

  7. Establishing score equivalence of the Functional Independence Measure motor scale and the Barthel Index, utilising the International Classification of Functioning, Disability and Health and Rasch measurement theory

    OpenAIRE

    Prodinger, B; O'Connor, RJ; Stucki, G; Tennant, A

    2017-01-01

    Introduction: Two widely used outcome measures to assess functioning in neurological rehabilitation are the Functional Independence Measure (FIM™) and the Barthel Index. The current study aims to establish the equivalence of the total score of the FIM™ motor scale and the Barthel Index through the application of the International Classification of Functioning, Disability and Health, and Rasch measurement theory. Methods: Secondary analysis of a large sample of patients with stroke, spinal cor...

  8. Estimating the Multilevel Rasch Model: With the lme4 Package

    Directory of Open Access Journals (Sweden)

    Harold Doran

    2007-02-01

    Full Text Available Traditional Rasch estimation of the item and student parameters via marginal maximum likelihood, joint maximum likelihood or conditional maximum likelihood, assume individuals in clustered settings are uncorrelated and items within a test that share a grouping structure are also uncorrelated. These assumptions are often violated, particularly in educational testing situations, in which students are grouped into classrooms and many test items share a common grouping structure, such as a content strand or a reading passage. Consequently, one possible approach is to explicitly recognize the clustered nature of the data and directly incorporate random effects to account for the various dependencies. This article demonstrates how the multilevel Rasch model can be estimated using the functions in R for mixed-effects models with crossed or partially crossed random effects. We demonstrate how to model the following hierarchical data structures: a individuals clustered in similar settings (e.g., classrooms, schools, b items nested within a particular group (such as a content strand or a reading passage, and c how to estimate a teacher × content strand interaction.

  9. The Stringent Response Induced by Phosphate Limitation Promotes Purine Salvage in Agrobacterium fabrum.

    Science.gov (United States)

    Sivapragasam, Smitha; Deochand, Dinesh K; Meariman, Jacob K; Grove, Anne

    2017-10-31

    Agrobacterium fabrum induces tumor growth in susceptible plant species. The upregulation of virulence genes that occurs when the bacterium senses plant-derived compounds is enhanced by acidic pH and limiting inorganic phosphate. Nutrient starvation may also trigger the stringent response, and purine salvage is among the pathways expected to be favored under such conditions. We show here that phosphate limitation induces the stringent response, as evidenced by production of (p)ppGpp, and that the xdhCSML operon encoding the purine salvage enzyme xanthine dehydrogenase is upregulated ∼15-fold. The xdhCSML operon is under control of the TetR family transcription factor XdhR; direct binding of ppGpp to XdhR attenuates DNA binding, and the enhanced xdhCSML expression correlates with increased cellular levels of (p)ppGpp. Xanthine dehydrogenase may also divert purines away from salvage pathways to form urate, the ligand for the transcription factor PecS, which in the plant pathogen Dickeya dadantii is a key regulator of virulence gene expression. However, urate levels remain low under conditions that produce increased levels of xdhCSML expression, and neither acidic pH nor limiting phosphate results in induction of genes under control of PecS. Instead, expression of such genes is induced only by externally supplemented urate. Taken together, our data indicate that purine salvage is favored during the stringent response induced by phosphate starvation, suggesting that control of this pathway may constitute a novel approach to modulating virulence. Because bacterial purine catabolism appears to be unaffected, as evidenced by the absence of urate accumulation, we further propose that the PecS regulon is induced by only host-derived urate.

  10. Towards the Development of Clinical Measures for Spinal Cord Injury Based on the International Classification of Functioning, Disability and Health With Rasch Analyses

    DEFF Research Database (Denmark)

    Ballert, Carolina S; Stucki, Gerold; Biering-Sørensen, Fin

    2014-01-01

    OBJECTIVES: To determine whether the International Classification of Functioning, Disability and Health (ICF) categories relevant to spinal cord injury (SCI) can be integrated in clinical measures and to obtain insights to guide their future operationalization. Specific aims are to find out whether...... the ICF categories relevant to SCI fit a Rasch model taking into consideration the dimensionality found in previous investigations, local item dependencies, or differential item functioning. DESIGN: All second-level ICF categories collected in the Development of ICF Core Sets for SCI project...... in specialized centers within 15 countries from 2006 through 2008. SETTING: Secondary data analysis. PARTICIPANTS: Adults (N=1048) with SCI from the early postacute and long-term living context. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Two unidimensional Rasch analyses: one for the ICF categories...

  11. Rasch modeling to assess Albanian and South African learners' preferences for real-life situations to be used in mathematics: a pilot study.

    Science.gov (United States)

    Kacerja, Suela; Julie, Cyril; Hadjerrouit, Said

    2013-01-01

    This paper reports on an investigation on the real-life situations students in grades 8 and 9 in South Africa and Albania prefer to use in Mathematics. The functioning of the instrument used to assess the order of preference learners from both countries have for contextual situations is assessed using Rasch modeling techniques. For both the cohorts, the data fit the Rasch model. The differential item functioning (DIF) analysis rendered 3 items operating differentially for the two cohorts. Explanations for these differences are provided in terms of differences in experiences learners in the two countries have related to some of the contextual situations. Implications for interpretation of international comparative tests are offered, as are the possibilities for the cross-country development of curriculum materials related to contexts that learners prefer to use in Mathematics.

  12. Global gene expression during stringent response in Corynebacterium glutamicum in presence and absence of the rel gene encoding (pppGpp synthase

    Directory of Open Access Journals (Sweden)

    Kalinowski Jörn

    2006-09-01

    Full Text Available Background The stringent response is the initial reaction of microorganisms to nutritional stress. During stringent response the small nucleotides (pppGpp act as global regulators and reprogram bacterial transcription. In this work, the genetic network controlled by the stringent response was characterized in the amino acid-producing Corynebacterium glutamicum. Results The transcriptome of a C. glutamicum rel gene deletion mutant, unable to synthesize (pppGpp and to induce the stringent response, was compared with that of its rel-proficient parent strain by microarray analysis. A total of 357 genes were found to be transcribed differentially in the rel-deficient mutant strain. In a second experiment, the stringent response was induced by addition of DL-serine hydroxamate (SHX in early exponential growth phase. The time point of the maximal effect on transcription was determined by real-time RT-PCR using the histidine and serine biosynthetic genes. Transcription of all of these genes reached a maximum at 10 minutes after SHX addition. Microarray experiments were performed comparing the transcriptomes of SHX-induced cultures of the rel-proficient strain and the rel mutant. The differentially expressed genes were grouped into three classes. Class A comprises genes which are differentially regulated only in the presence of an intact rel gene. This class includes the non-essential sigma factor gene sigB which was upregulated and a large number of genes involved in nitrogen metabolism which were downregulated. Class B comprises genes which were differentially regulated in response to SHX in both strains, independent of the rel gene. A large number of genes encoding ribosomal proteins fall into this class, all being downregulated. Class C comprises genes which were differentially regulated in response to SHX only in the rel mutant. This class includes genes encoding putative stress proteins and global transcriptional regulators that might be

  13. Assessment of upper limb capacity in children with unilateral cerebral palsy: construct validity of a Rasch-reduced Modified House Classification.

    Science.gov (United States)

    Geerdink, Yvonne; Lindeboom, Robert; de Wolf, Sander; Steenbergen, Bert; Geurts, Alexander C H; Aarts, Pauline

    2014-06-01

    The aim of this study was to test and improve the unidimensionality and item hierarchy of the Modified House Classification (MHC) for the assessment of upper limb capacity in children with unilateral cerebral palsy (CP) using Rasch analysis. The construct validity of the Rasch-reduced item set was evaluated. Modified House Classification items were scored from 369 videotaped assessments of 159 children with unilateral CP (98 males, 61 females; median age 6y 6mo, range 2y 1mo-17y 5mo). Construct validity was tested in 40 other children with unilateral CP (21 males, 19 females; median age 8y 2mo, range 3y 3mo-17y 6mo) by comparing total scores with the Manual Ability Classification System (MACS) and the ABILHAND-Kids scale. Fifteen MHC items could be included in the Rasch analysis. The excluded items were either too easy or too difficult. Fourteen items fitted the unidimensional model (χ(2) =41.3, df=39, p=0.37). The hierarchy of these items was different from the original MHC. There was a significant correlation with the MACS (r=-0.901, p<0.001) and the ABILHAND-Kids scale (r=0.558, p<0.001). The original item hierarchy of the MHC can be improved in order to use its sum score for the assessment of upper limb capacity in children with unilateral CP. The Rasch-reduced 14-item MHC with weighted sum score shows good construct validity to measure functional capacity of the affected hand in children with unilateral CP. © 2014 Mac Keith Press.

  14. Sample Size and Statistical Conclusions from Tests of Fit to the Rasch Model According to the Rasch Unidimensional Measurement Model (Rumm) Program in Health Outcome Measurement.

    Science.gov (United States)

    Hagell, Peter; Westergren, Albert

    Sample size is a major factor in statistical null hypothesis testing, which is the basis for many approaches to testing Rasch model fit. Few sample size recommendations for testing fit to the Rasch model concern the Rasch Unidimensional Measurement Models (RUMM) software, which features chi-square and ANOVA/F-ratio based fit statistics, including Bonferroni and algebraic sample size adjustments. This paper explores the occurrence of Type I errors with RUMM fit statistics, and the effects of algebraic sample size adjustments. Data with simulated Rasch model fitting 25-item dichotomous scales and sample sizes ranging from N = 50 to N = 2500 were analysed with and without algebraically adjusted sample sizes. Results suggest the occurrence of Type I errors with N less then or equal to 500, and that Bonferroni correction as well as downward algebraic sample size adjustment are useful to avoid such errors, whereas upward adjustment of smaller samples falsely signal misfit. Our observations suggest that sample sizes around N = 250 to N = 500 may provide a good balance for the statistical interpretation of the RUMM fit statistics studied here with respect to Type I errors and under the assumption of Rasch model fit within the examined frame of reference (i.e., about 25 item parameters well targeted to the sample).

  15. Hawks, Doves and Rasch decisions: Understanding the influence of different cycles of an OSCE on students' scores using Many Facet Rasch Modeling.

    Science.gov (United States)

    Yeates, Peter; Sebok-Syer, Stefanie S

    2017-01-01

    OSCEs are commonly conducted in multiple cycles (different circuits, times, and locations), yet the potential for students' allocation to different OSCE cycles is rarely considered as a source of variance-perhaps in part because conventional psychometrics provide limited insight. We used Many Facet Rasch Modeling (MFRM) to estimate the influence of "examiner cohorts" (the combined influence of the examiners in the cycle to which each student was allocated) on students' scores within a fully nested multi-cycle OSCE. Observed average scores for examiners cycles varied by 8.6%, but model-adjusted estimates showed a smaller range of 4.4%. Most students' scores were only slightly altered by the model; the greatest score increase was 5.3%, and greatest score decrease was -3.6%, with 2 students passing who would have failed. Despite using 16 examiners per cycle, examiner variability did not completely counter-balance, resulting in an influence of OSCE cycles on students' scores. Assumptions were required for the MFRM analysis; innovative procedures to overcome these limitations and strengthen OSCEs are discussed. OSCE cycle allocation has the potential to exert a small but unfair influence on students' OSCE scores; these little-considered influences should challenge our assumptions and design of OSCEs.

  16. Rasch validation of the Prosthetic Mobility Questionnaire: A new outcome measure for assessing mobility in people with lower limb amputation.

    Science.gov (United States)

    Franchignoni, Franco; Monticone, Marco; Giordano, Andrea; Rocca, Barbara

    2015-05-01

    To create a new outcome measure of mobility in people with lower limb amputation, based on a pool of 14 items assessing prosthetic mobility, comprising the 12-item Prosthesis Evaluation Questionnaire (Mobility Section) plus 2 new items. Cross-sectional study. A total of 100 subjects (median age 58 years; 46 males; median body mass index 23.8) who had recently undergone lower limb amputation. Each patient completed the 14-item questionnaire twice: (i) at admission to the rehabilitation unit for prosthetic rehabilitation training; (ii) at 6-month follow-up after discharge. After Rasch analysis, 2 items were deleted (one due to misfit, the other because showing large (>  0.30) positive correlation of residuals with two other items (local dependence). The remaining items fitted the Rasch model (internal construct validity), giving a new 12-item scale with a 5-level response format, the Prosthetic Mobility Questionnaire (PMQ), which demonstrated unidimensionality, lack of differential item functioning, and good reliability indices (person-separation reliability = 0.87; Cronbach's alpha 0.88). Although further studies are needed to increase confidence in clinical use of the PMQ, this new questionnaire appears to be a promising, psychometrically-sound patient-reported outcome measure for assessment of mobility in subjects with lower limb amputation who use a prosthesis.

  17. Improving the measurement of health-related quality of life in adolescent with idiopathic scoliosis: the SRS-7, a Rasch-developed short form of the SRS-22 questionnaire.

    Science.gov (United States)

    Caronni, Antonio; Zaina, Fabio; Negrini, Stefano

    2014-04-01

    Scoliosis Research Society-22 (SRS-22) questionnaire was developed to evaluate health-related quality of life (HRQL) in adolescent idiopathic scoliosis (AIS) patients. Rasch analysis (RA) is a statistical procedure which turns questionnaire ordinal scores into interval measures. Measures from Rasch-compatible questionnaires can be used, similar to body temperature or blood pressure, to quantify disease severity progression and treatment efficacy. Purpose of the current work is to present Rasch analysis (RA) of the SRS-22 questionnaire and to develop an SRS-22 Rasch-approved short form. 300 SRS-22 were randomly collected from 2447 consecutive IS adolescents at their first evaluation (229 females; 13.9 ± 1.9 years; 26.9 ± 14.7 Cobb°) in a scoliosis outpatient clinic. RA showed both disordered thresholds and overall misfit of the SRS-22. Sixteen items were re-scored and two misfitting items (6 and 14) removed to obtain a Rasch-compatible questionnaire. Participants HRQL measured too high with the rearranged questionnaire, indicating a severe SRS-22 ceiling effect. RA also highlighted SRS-22 multidimensionality, with pain/function not merging with self-image/mental health items. Item 3 showed differential item functioning (DIF) for both curve and hump amplitude. A 7-item questionnaire (SRS-7) was prepared by selecting single items from the original SRS-22. SRS-7 showed fit to the model, unidimensionality and no DIF. Compared with the SRS-22, the short form scale shows better targeting of the participants' population. RA shows that SRS-22 has poor clinimetric properties; moreover, when used with AIS at first evaluation, SRS-22 is affected by a severe ceiling effect. SRS-7, an SRS-22 7-item short form questionnaire, provides an HRQL interval measure better tailored to these participants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Dual Regulation of Bacillus subtilis kinB Gene Encoding a Sporulation Trigger by SinR through Transcription Repression and Positive Stringent Transcription Control

    Directory of Open Access Journals (Sweden)

    Yasutaro Fujita

    2017-12-01

    Full Text Available It is known that transcription of kinB encoding a trigger for Bacillus subtilis sporulation is under repression by SinR, a master repressor of biofilm formation, and under positive stringent transcription control depending on the adenine species at the transcription initiation nucleotide (nt. Deletion and base substitution analyses of the kinB promoter (PkinB region using lacZ fusions indicated that either a 5-nt deletion (Δ5, nt -61/-57, +1 is the transcription initiation nt or the substitution of G at nt -45 with A (G-45A relieved kinB repression. Thus, we found a pair of SinR-binding consensus sequences (GTTCTYT; Y is T or C in an inverted orientation (SinR-1 between nt -57/-42, which is most likely a SinR-binding site for kinB repression. This relief from SinR repression likely requires SinI, an antagonist of SinR. Surprisingly, we found that SinR is essential for positive stringent transcription control of PkinB. Electrophoretic mobility shift assay (EMSA analysis indicated that SinR bound not only to SinR-1 but also to SinR-2 (nt -29/-8 consisting of another pair of SinR consensus sequences in a tandem repeat arrangement; the two sequences partially overlap the ‘-35’ and ‘-10’ regions of PkinB. Introduction of base substitutions (T-27C C-26T in the upstream consensus sequence of SinR-2 affected positive stringent transcription control of PkinB, suggesting that SinR binding to SinR-2 likely causes this positive control. EMSA also implied that RNA polymerase and SinR are possibly bound together to SinR-2 to form a transcription initiation complex for kinB transcription. Thus, it was suggested in this work that derepression of kinB from SinR repression by SinI induced by Spo0A∼P and occurrence of SinR-dependent positive stringent transcription control of kinB might induce effective sporulation cooperatively, implying an intimate interplay by stringent response, sporulation, and biofilm formation.

  19. Examination of an eHealth literacy scale and a health literacy scale in a population with moderate to high cardiovascular risk: Rasch analyses.

    Directory of Open Access Journals (Sweden)

    Sarah S Richtering

    Full Text Available Electronic health (eHealth strategies are evolving making it important to have valid scales to assess eHealth and health literacy. Item response theory methods, such as the Rasch measurement model, are increasingly used for the psychometric evaluation of scales. This paper aims to examine the internal construct validity of an eHealth and health literacy scale using Rasch analysis in a population with moderate to high cardiovascular disease risk.The first 397 participants of the CONNECT study completed the electronic health Literacy Scale (eHEALS and the Health Literacy Questionnaire (HLQ. Overall Rasch model fit as well as five key psychometric properties were analysed: unidimensionality, response thresholds, targeting, differential item functioning and internal consistency.The eHEALS had good overall model fit (χ2 = 54.8, p = 0.06, ordered response thresholds, reasonable targeting and good internal consistency (person separation index (PSI 0.90. It did, however, appear to measure two constructs of eHealth literacy. The HLQ subscales (except subscale 5 did not fit the Rasch model (χ2: 18.18-60.60, p: 0.00-0.58 and had suboptimal targeting for most subscales. Subscales 6 to 9 displayed disordered thresholds indicating participants had difficulty distinguishing between response options. All subscales did, nonetheless, demonstrate moderate to good internal consistency (PSI: 0.62-0.82.Rasch analyses demonstrated that the eHEALS has good measures of internal construct validity although it appears to capture different aspects of eHealth literacy (e.g. using eHealth and understanding eHealth. Whilst further studies are required to confirm this finding, it may be necessary for these constructs of the eHEALS to be scored separately. The nine HLQ subscales were shown to measure a single construct of health literacy. However, participants' scores may not represent their actual level of ability, as distinction between response categories was unclear for

  20. Does dishonesty really invite third-party punishment? Results of a more stringent test.

    Science.gov (United States)

    Konishi, Naoki; Ohtsubo, Yohsuke

    2015-05-01

    Many experiments have demonstrated that people are willing to incur cost to punish norm violators even when they are not directly harmed by the violation. Such altruistic third-party punishment is often considered an evolutionary underpinning of large-scale human cooperation. However, some scholars argue that previously demonstrated altruistic third-party punishment against fairness-norm violations may be an experimental artefact. For example, envy-driven retaliatory behaviour (i.e. spite) towards better-off unfair game players may be misidentified as altruistic punishment. Indeed, a recent experiment demonstrated that participants ceased to inflict third-party punishment against an unfair player once a series of key methodological problems were systematically controlled for. Noticing that a previous finding regarding apparently altruistic third-party punishment against honesty-norm violations may have been subject to methodological issues, we used a different and what we consider to be a more sound design to evaluate these findings. Third-party punishment against dishonest players withstood this more stringent test. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  1. Bulk development and stringent selection of microsatellite markers in the western flower thrips Frankliniella occidentalis.

    Science.gov (United States)

    Cao, Li-Jun; Li, Ze-Min; Wang, Ze-Hua; Zhu, Liang; Gong, Ya-Jun; Chen, Min; Wei, Shu-Jun

    2016-05-20

    Recent improvements in next-generation sequencing technologies have enabled investigation of microsatellites on a genome-wide scale. Faced with a huge amount of candidates, the use of appropriate marker selection criteria is crucial. Here, we used the western flower thrips Frankliniella occidentalis for an empirical microsatellite survey and validation; 132,251 candidate microsatellites were identified, 92,102 of which were perfect. Dinucleotides were the most abundant category, while (AG)n was the most abundant motif. Sixty primer pairs were designed and validated in two natural populations, of which 30 loci were polymorphic, stable, and repeatable, but not all in Hardy-Weinberg equilibrium (HWE) and linkage equilibrium. Four marker panels were constructed to understand effect of marker selection on population genetic analyses: (i) only accept loci with single nucleotide insertions (SNI); (ii) only accept the most polymorphic loci (MP); (iii) only accept loci that did not deviate from HWE, did not show SNIs, and had unambiguous peaks (SS) and (iv) all developed markers (ALL). Although the MP panel resulted in microsatellites of highest genetic diversity followed by the SNI, the SS performed best in individual assignment. Our study proposes stringent criteria for selection of microsatellites from a large-scale number of genomic candidates for population genetic studies.

  2. The Stringent Response Promotes Antibiotic Resistance Dissemination by Regulating Integron Integrase Expression in Biofilms

    Directory of Open Access Journals (Sweden)

    Emilie Strugeon

    2016-08-01

    Full Text Available Class 1 integrons are genetic systems that enable bacteria to capture and express gene cassettes. These integrons, when isolated in clinical contexts, most often carry antibiotic resistance gene cassettes. They play a major role in the dissemination of antibiotic resistance among Gram-negative bacteria. The key element of integrons is the integrase, which allows gene cassettes to be acquired and shuffled. Planktonic culture experiments have shown that integrase expression is regulated by the bacterial SOS response. In natural settings, however, bacteria generally live in biofilms, which are characterized by strong antibiotic resilience and by increased expression of stress-related genes. Here, we report that under biofilm conditions, the stringent response, which is induced upon starvation, (i increases basal integrase and SOS regulon gene expression via induction of the SOS response and (ii exerts biofilm-specific regulation of the integrase via the Lon protease. This indicates that biofilm environments favor integron-mediated acquisition of antibiotic resistance and other adaptive functions encoded by gene cassettes.

  3. Understanding Metallic Bonding: Structure, Process and Interaction by Rasch Analysis

    Science.gov (United States)

    Cheng, Maurice M. W.; Oon, Pey-Tee

    2016-01-01

    This paper reports the results of a survey of 3006 Year 10-12 students on their understandings of metallic bonding. The instrument was developed based on Chi's ontological categories of scientific concepts and students' understanding of metallic bonding as reported in the literature. The instrument has two parts. Part one probed into students'…

  4. Rasch Analysis of the Fullerton Advanced Balance (FAB) Scale

    OpenAIRE

    Klein, Penelope J.; Fiedler, Roger C.; Rose, Debra J.

    2011-01-01

    Purpose: This cross-sectional study explores the psychometric properties and dimensionality of the Fullerton Advanced Balance (FAB) Scale, a multi-item balance test for higher-functioning older adults.

  5. Rasch Analysis of the Routines-Based Interview Implementation Checklist

    Science.gov (United States)

    Boavida, Tânia; Akers, Kate; McWilliam, R. A.; Jung, Lee Ann

    2015-01-01

    The Routines-­Based Interview (RBI) is useful for developing functional outcomes/goals, for establishing strong relationships with families, and for assessing the family's true needs. In this study, the authors investigated the psychometric properties of the RBI Implementation Checklist, conducted by 120 early intervention professionals,…

  6. Analysis of Letter Name Knowledge Using Rasch Measurement

    Science.gov (United States)

    Bowles, Ryan P.; Skibbe, Lori E.; Justice, Laura M.

    2011-01-01

    Letter name knowledge (LNK) is a key predictor of later reading ability and has been emphasized strongly in recent educational policy. Studies of LNK have implicitly treated it as a unidimensional construct with all letters equally relevant to its measurement. However, some empirical research suggests that contextual factors can affect the…

  7. Is the Aggression Questionnaire Bias Free? A Rasch Analysis

    Science.gov (United States)

    Abd-El-Fattah, Sabry M.

    2007-01-01

    Buss and Perry (1992) developed the Aggression Questionnaire (AQ) to assess aggressiveness as a personality trait in high school and college samples. The AQ has been used by researchers in United States, Italy, Germany, Netherland, Japan, Canada, and Greece. The present study is reported on an Arabic adapted version of the AQ among a sample of 510…

  8. A Rasch Analysis of the Teachers Music Confidence Scale

    Science.gov (United States)

    Yim, Hoi Yin Bonnie; Abd-El-Fattah, Sabry; Lee, Lai Wan Maria

    2007-01-01

    This article presents a new measure of teachers' confidence to conduct musical activities with young children; Teachers Music Confidence Scale (TMCS). The TMCS was developed using a sample of 284 in-service and pre-service early childhood teachers in Hong Kong Special Administrative Region (HKSAR). The TMCS consisted of 10 musical activities.…

  9. Using a Rasch Model to Account for Guessing as a Source of Low Discrimination.

    Science.gov (United States)

    Humphry, Stephen

    2015-01-01

    The most common approach to modelling item discrimination and guessing for multiple-choice questions is the three parameter logistic (3PL) model. However, proponents of Rasch models generally avoid using the 3PL model because to model guessing entails sacrificing the distinctive property and advantages of Rasch models. One approach to dealing with guessing based on the application of Rasch models is to omit responses in which guessing appears to play a significant role. However, this approach entails loss of information and it does not account for variable item discrimination. It has been shown, though, that provided specific constraints are met, it is possible to parameterize discrimination while preserving the distinctive property of Rasch models. This article proposes an approach that uses Rasch models to account for guessing on standard multiple-choice items simply by treating it as a source of low item discrimination. Technical considerations are noted although a detailed examination of such considerations is beyond the scope of this article.

  10. Applying the Many-Facet Rasch Model to Evaluate PowerPoint Presentation Performance in Higher Education

    Science.gov (United States)

    Basturk, Ramazan

    2008-01-01

    This study investigated the usefulness of the many-facet Rasch model (MFRM) in evaluating the quality of performance related to PowerPoint presentations in higher education. The Rasch Model utilizes item response theory stating that the probability of a correct response to a test item/task depends largely on a single parameter, the ability of the…

  11. TESTING THE ASSUMPTIONS AND INTERPRETING THE RESULTS OF THE RASCH MODEL USING LOG-LINEAR PROCEDURES IN SPSS

    NARCIS (Netherlands)

    TENVERGERT, E; GILLESPIE, M; KINGMA, J

    This paper shows how to use the log-linear subroutine of SPSS to fit the Rasch model. It also shows how to fit less restrictive models obtained by relaxing specific assumptions of the Rasch model. Conditional maximum likelihood estimation was achieved by including dummy variables for the total

  12. Measuring Anger Types among Malaysian Adolescents using the Rasch Model.

    Science.gov (United States)

    Khairani, Ahmad Zamri; Ahmad, Nor Shafrin; Khairani, Mohd Zahuri

    Adolescences is an important transitional phase in human development where they experience physiological as well as psychological changes. Nevertheless, these changes are often understood by teachers, parents, and even the adolescents themselves. Thus, conflicts exist and adolescents are affected from the conflict physically and emotionally. An important state of emotions that result from this conflict is anger. This article describes the development and validation of the 34-item Adolescent Anger Inventory (AAI) to measure types of anger among Malaysian adolescents. A sample of 2,834 adolescents in secondary school who provide responses that were analyzed using Rasch model measurement framework. The 4 response category worked satisfactorily for the scale developed. A total of 11 items did not fit to the model's expectations, and thus dropped from the final scale. The scale also demonstrated satisfactory reliability and separation evidence. Also, items in the AAI depicted no evidence of DIF between 14- and 16-year-old adolescents. Nevertheless, the AAI did not have sufficient items to target adolescents with a high level of physical aggressive anger.

  13. A multi-factor Rasch scale for artistic judgment.

    Science.gov (United States)

    Bezruczko, Nikolaus

    2002-01-01

    Measurement properties are reported for a combined scale of abstract and figurative artistic judgment aptitude items. Abstract items are synthetic, rule-based images from Visual Designs Test which implements a statistical algorithm to control design complexity and redundancy, and figurative items are canvas paintings in five styles, Fauvism, Post-Impressionism, Surrealism, Renaissance, and Baroque especially created for this research. The paintings integrate syntactic structure from VDT Abstract designs with thematic content for each style at four levels of complexity while controlling redundancy. Trained test administrators collected preference for synthetic abstract designs and authentic figurative art from 462 examinees in Johnson O'Connor Research Foundation testing offices in Boston, New York, Chicago, and Dallas. The Rasch model replicated measurement properties for VDT Abstract items and identified an item hierarchy that was statistically invariant between genders and generally stable across age for new, authentic figurative items. Further examination of the figurative item hierarchy revealed that complexity interacts with style and meaning. Sound measurement properties for a combined VDT Abstract and Figurative scale shows promise for a comprehensive artistic judgment construct.

  14. Applying the Many-Facet Rasch Measurement Model to Explore Reviewer Ratings of Conference Proposals.

    Science.gov (United States)

    Bradley, Kelly D; Peabody, Michael R; Mensah, Richard K

    For academic conferences, when proposals are submit they are often judged using a rating scale on identified criterion by reviewers who have a shared interest and expertise in the area under consideration. Given the multiple and varied reviewers, an analysis of psychometric properties like rater severity and consistency are important. However, many of the problems that plague the conference proposal selection process are the same issues that plague survey research: rater bias/severity, misuse of rating scale, and the use of raw scores as measures. We propose the use of the many-facet Rasch measurement model (MFRM) to combat these shortcomings and improve the quality of the conference proposal selection process. A set of American Educational Research Association (AERA) Special Interest Group (SIG) proposals is used as an example. The results identify proposals that were accepted based on calculating the mean of summed raw scores, but when MFRM is applied to adjust for judge severity the rank order of the proposals is substantially altered.

  15. Improving measurement in nutrition literacy research using Rasch modelling: examining construct validity of stage-specific 'critical nutrition literacy' scales.

    Science.gov (United States)

    Guttersrud, Oystein; Dalane, Jorån Østerholt; Pettersen, Sverre

    2014-04-01

    Critical nutrition literacy (CNL), as an increasingly important area in public health nutrition, can be defined as the ability to critically analyse nutrition information, increase awareness and participate in action to address barriers to healthy eating behaviours. Far too little attention has been paid to establishing valid instruments for measuring CNL. The aim of the present study was to assess the appropriateness of utilizing the latent scales of a newly developed instrument assessing nursing students' 'engagement in dietary habits' (the 'engagement' scale) and their level of 'taking a critical stance towards nutrition claims and their sources' (the 'claims' scale). Data were gathered by distributing a nineteen-item paper-and-pencil self-report questionnaire to university colleges offering nursing education. The study had a cross-sectional design using Rasch analysis. Data management and analysis were performed using the software packages RUMM2030 and SPSS version 20. School personnel handed out the questionnaires. Four hundred and seventy-three students at ten university colleges across Norway responded (52% response rate). Disordered thresholds were rescored, an under-discriminating item was discarded and one item showing uniform differential item functioning was split. The assumption of item locations being differentiated by stages was strengthened. The analyses demonstrated possible dimension violations of local independence in the 'claims' scale data and the 'engagement' scale could have been better targeted. The study demonstrates the usefulness of Rasch analysis in assessing the psychometric properties of scales developed to measure CNL. Qualitative research designs could further improve our understanding of CNL scales.

  16. Adaptation to fluctuating temperatures in an RNA virus is driven by the most stringent selective pressure.

    Directory of Open Access Journals (Sweden)

    María Arribas

    Full Text Available The frequency of change in the selective pressures is one of the main factors driving evolution. It is generally accepted that constant environments select specialist organisms whereas changing environments favour generalists. The particular outcome achieved in either case also depends on the relative strength of the selective pressures and on the fitness costs of mutations across environments. RNA viruses are characterized by their high genetic diversity, which provides fast adaptation to environmental changes and helps them evade most antiviral treatments. Therefore, the study of the adaptive possibilities of RNA viruses is highly relevant for both basic and applied research. In this study we have evolved an RNA virus, the bacteriophage Qβ, under three different temperatures that either were kept constant or alternated periodically. The populations obtained were analyzed at the phenotypic and the genotypic level to characterize the evolutionary process followed by the virus in each case and the amount of convergent genetic changes attained. Finally, we also investigated the influence of the pre-existent genetic diversity on adaptation to high temperature. The main conclusions that arise from our results are: i under periodically changing temperature conditions, evolution of bacteriophage Qβ is driven by the most stringent selective pressure, ii there is a high degree of evolutionary convergence between replicated populations and also among populations evolved at different temperatures, iii there are mutations specific of a particular condition, and iv adaptation to high temperatures in populations differing in their pre-existent genetic diversity takes place through the selection of a common set of mutations.

  17. The rapidly evolving centromere-specific histone has stringent functional requirements in Arabidopsis thaliana.

    Science.gov (United States)

    Ravi, Maruthachalam; Kwong, Pak N; Menorca, Ron M G; Valencia, Joel T; Ramahi, Joseph S; Stewart, Jodi L; Tran, Robert K; Sundaresan, Venkatesan; Comai, Luca; Chan, Simon W-L

    2010-10-01

    Centromeres control chromosome inheritance in eukaryotes, yet their DNA structure and primary sequence are hypervariable. Most animals and plants have megabases of tandem repeats at their centromeres, unlike yeast with unique centromere sequences. Centromere function requires the centromere-specific histone CENH3 (CENP-A in human), which replaces histone H3 in centromeric nucleosomes. CENH3 evolves rapidly, particularly in its N-terminal tail domain. A portion of the CENH3 histone-fold domain, the CENP-A targeting domain (CATD), has been previously shown to confer kinetochore localization and centromere function when swapped into human H3. Furthermore, CENP-A in human cells can be functionally replaced by CENH3 from distantly related organisms including Saccharomyces cerevisiae. We have used cenh3-1 (a null mutant in Arabidopsis thaliana) to replace endogenous CENH3 with GFP-tagged variants. A H3.3 tail domain-CENH3 histone-fold domain chimera rescued viability of cenh3-1, but CENH3's lacking a tail domain were nonfunctional. In contrast to human results, H3 containing the A. thaliana CATD cannot complement cenh3-1. GFP-CENH3 from the sister species A. arenosa functionally replaces A. thaliana CENH3. GFP-CENH3 from the close relative Brassica rapa was targeted to centromeres, but did not complement cenh3-1, indicating that kinetochore localization and centromere function can be uncoupled. We conclude that CENH3 function in A. thaliana, an organism with large tandem repeat centromeres, has stringent requirements for functional complementation in mitosis.

  18. A Rasch rating scale modeling of the Schutte Self-Report Emotional Intelligence scale in a sample of international students.

    Science.gov (United States)

    Kim, Do-Hong; Wang, Chuang; Ng, Kok-Mun

    2010-12-01

    This study examined the psychometric properties of the Schutte Self-Report Emotional Intelligence (SSREI) scale in a sample of international students studying in the U.S. universities using Rasch analysis. The results indicated that the original five-category rating structure may not function effectively for the international student sample. The results also revealed that although most of the items in the SSREI scale contributed to a single underlying construct, reverse-keyed items appeared to be problematic. Examination of the person-item map suggested that the items may be inappropriately targeted for this sample. In sum, the original version of the SSREI scale needs further improvement to adequately measure emotional intelligence.

  19. Investigation of the prominent barriers to lean manufacturing implementation in Malaysian food and beverages industry using Rasch Model

    Science.gov (United States)

    Khusaini, N. S.; Ismail, A.; Rashid, A. A.

    2016-02-01

    This paper presents a preliminary study on the prominent barriers to lean manufacturing implementation in Malaysian Food and Beverages Industry. A survey was carried out to determine the most prominent barriers of lean manufacturing implementation that are currently being faced in this industry. The amount of barriers identified for this study is twenty seven. Out of 1309 available organizations, a total of 300 organizations have been randomly selected as respondents, and 53 organizations responded. From the variable map, the analysis shows that, the negative perception towards lean manufacturing top the list as the most agreeable barrier, while the technical barriers came after it. It can also be seen from the variable map that averagely, lack of vision and direction is the barrier that is being faced. Finally, this is perhaps the first attempt in investigating the prominent barriers to Lean Manufacturing implementation in Malaysian food and beverages industry using Rasch Model.

  20. Calibrating Charisma: The many-facet Rasch model for leader measurement and automated coaching

    Science.gov (United States)

    Barney, Matt

    2016-11-01

    No one is a leader unless others follow. Consequently, leadership is fundamentally a social judgment construct, and may be best measured via a Many Facet Rasch Model designed for this purpose. Uniquely, the MFRM allows for objective, accurate and precise estimation of leader attributes, along with identification of rater biases and other distortions of the available information. This presentation will outline a mobile computer-adaptive measurement system that measures and develops charisma, among others. Uniquely, the approach calibrates and mass-personalizes artificially intelligent, Rasch-calibrated electronic coaching that is neither too hard nor too easy but “just right” to help each unique leader develop improved charisma.

  1. Stringently Defined Otitis Prone Children Demonstrate Deficient Naturally Induced Mucosal Antibody Response to Moraxella catarrhalis Proteins

    Directory of Open Access Journals (Sweden)

    Dabin Ren

    2017-08-01

    Full Text Available Moraxella catarrhalis (Mcat is a prominent mucosal pathogen causing acute otitis media (AOM. We studied Mcat nasopharyngeal (NP colonization, AOM frequency and mucosal antibody responses to four vaccine candidate Mcat proteins: outer membrane protein (OMP CD, oligopeptide permease (Opp A, hemagglutinin (Hag, and Pilin A clade 2 (PilA2 from stringently defined otitis prone (sOP children, who experience the greatest burden of disease, compared to non-otitis prone (NOP children. sOP children had higher NP colonization of Mcat (30 vs. 22%, P = 0.0003 and Mcat-caused AOM rates (49 vs. 24%, P < 0.0001 than NOP children. Natural acquisition of mucosal antibodies to Mcat proteins OMP CD (IgG, P < 0.0001, OppA (IgG, P = 0.018, Hag (IgG and IgA, both P < 0.0001, and PilA2 (IgA, P < 0.0001 was lower in sOP than NOP children. Higher levels of mucosal IgG to Hag (P = 0.039 and PilA2 (P = 0.0076, and IgA to OMP CD (P = 0.010, OppA (P = 0.030, and PilA2 (P = 0.043 were associated with lower carriage of Mcat in NOP but not sOP children. Higher levels of mucosal IgG to OMP CD (P = 0.0070 and Hag (P = 0.0003, and IgA to Hag (P = 0.0067 at asymptomatic colonization than those at onset of AOM were associated with significantly lower rate of Mcat NP colonization progressing to AOM in NOP compared to sOP children (3 vs. 26%, P < 0.0001. In conclusion, sOP children had a diminished mucosal antibody response to Mcat proteins, which was associated with higher frequencies of asymptomatic NP colonization and NP colonization progressing to Mcat-caused AOM. Enhancing Mcat antigen-specific mucosal immune responses to levels higher than achieved by natural exposure will be necessary to prevent AOM in sOP children.

  2. Role of the Stringent Stress Response in the Antibiotic Resistance Phenotype of Methicillin-Resistant Staphylococcus aureus.

    Science.gov (United States)

    Aedo, Sandra; Tomasz, Alexander

    2016-04-01

    Resistance to beta-lactam antibiotics in methicillin-resistantStaphylococcus aureus(MRSA) requires the presence of an acquired genetic determinant,mecAormecC, which encode penicillin-binding protein PBP2A or PBP2A', respectively. Although all MRSA strains share a mechanism of resistance, the phenotypic expression of beta-lactam resistance shows considerable strain-to-strain variation. The stringent stress response, a stress response that results from nutrient limitation, was shown to play a key role in determining the resistance level of an MRSA strain. In the present study, we validated the impact of the stringent stress response on transcription and translation ofmecAin the MRSA clinical isolate strain N315, which also carries known regulatory genes (mecI/mecR1/mecR2andblaI/blaR1) formecAtranscription. We showed that the impact of the stringent stress response on the resistance level may be restricted to beta-lactam resistance based on a "foreign" determinant such asmecA, as opposed to resistance based on mutations in the nativeS. aureusdeterminantpbpB(encoding PBP2). Our observations demonstrate that high-level resistance mediated by the stringent stress response follows the current model of beta-lactam resistance in which the native PBP2 protein is also essential for expression of the resistance phenotype. We also show that theStaphylococcus sciuri pbpDgene (also calledmecAI), the putative evolutionary precursor ofmecA, confers oxacillin resistance in anS. aureusstrain, generating a heterogeneous phenotype that can be converted to high and homogenous resistance by induction of the stringent stress response in the bacteria. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  3. The Cervical Dystonia Impact Profile (CDIP-58: Can a Rasch developed patient reported outcome measure satisfy traditional psychometric criteria?

    Directory of Open Access Journals (Sweden)

    Bhatia Kailash P

    2008-08-01

    Full Text Available Abstract Background The United States Food and Drug Administration (FDA are currently producing guidelines for the scientific adequacy of patient reported outcome measures (PROMs in clinical trials, which will have implications for the selection of scales used in future clinical trials. In this study, we examine how the Cervical Dystonia Impact Profile (CDIP-58, a rigorous Rasch measurement developed neurologic PROM, stands up to traditional psychometric criteria for three reasons: 1 provide traditional psychometric evidence for the CDIP-58 in line with proposed FDA guidelines; 2 enable researchers and clinicians to compare it with existing dystonia PROMs; and 3 help researchers and clinicians bridge the knowledge gap between old and new methods of reliability and validity testing. Methods We evaluated traditional psychometric properties of data quality, scaling assumptions, targeting, reliability and validity in a group of 391 people with CD. The main outcome measures used were the CDIP-58, Medical Outcome Study Short Form-36, the 28-item General Health Questionnaire, and Hospital and Anxiety and Depression Scale. Results A total of 391 people returned completed questionnaires (corrected response rate 87%. Analyses showed: 1 data quality was high (low missing data ≤ 4%, subscale scores could be computed for > 96% of the sample; 2 item groupings passed tests for scaling assumptions; 3 good targeting (except for the Sleep subscale, ceiling effect = 27%; 4 good reliability (Cronbach's alpha ≥ 0.92, test-retest intraclass correlations ≥ 0.83; and 5 validity was supported. Conclusion This study has shown that new psychometric methods can produce a PROM that stands up to traditional criteria and supports the clinical advantages of Rasch analysis.

  4. Imputation by the mean score should be avoided when validating a Patient Reported Outcomes questionnaire by a Rasch model in presence of informative missing data

    LENUS (Irish Health Repository)

    Hardouin, Jean-Benoit

    2011-07-14

    Abstract Background Nowadays, more and more clinical scales consisting in responses given by the patients to some items (Patient Reported Outcomes - PRO), are validated with models based on Item Response Theory, and more specifically, with a Rasch model. In the validation sample, presence of missing data is frequent. The aim of this paper is to compare sixteen methods for handling the missing data (mainly based on simple imputation) in the context of psychometric validation of PRO by a Rasch model. The main indexes used for validation by a Rasch model are compared. Methods A simulation study was performed allowing to consider several cases, notably the possibility for the missing values to be informative or not and the rate of missing data. Results Several imputations methods produce bias on psychometrical indexes (generally, the imputation methods artificially improve the psychometric qualities of the scale). In particular, this is the case with the method based on the Personal Mean Score (PMS) which is the most commonly used imputation method in practice. Conclusions Several imputation methods should be avoided, in particular PMS imputation. From a general point of view, it is important to use an imputation method that considers both the ability of the patient (measured for example by his\\/her score), and the difficulty of the item (measured for example by its rate of favourable responses). Another recommendation is to always consider the addition of a random process in the imputation method, because such a process allows reducing the bias. Last, the analysis realized without imputation of the missing data (available case analyses) is an interesting alternative to the simple imputation in this context.

  5. Direct-to-physician and direct-to-consumer advertising: Time to have stringent regulations.

    Science.gov (United States)

    Kannan, S; Gowri, S; Tyagi, V; Kohli, S; Jain, R; Kapil, P; Bhardwaj, A

    2015-01-01

    the opinion regarding DTCA, 69.9% physicians had a patient discussing DTCA that was clinically inappropriate. One hundred (64.5%) out of 155 physicians opined that DTCA encourage patients to attend physicians regarding preventive healthcare. On the contrary, 82/155 (52.9%) physicians felt that DTCA would damage the same. Similarly, 69 out of the total 100 patients felt that drug advertisements aid them to have better discussions with their treating physicians. Surprisingly, a large majority (91/100) were of the opinion that only safe drugs are allowed to be advertised. To conclude, from the findings of this study both the physicians and patients should be cautious and not overzealous while dealing with drug advertisements or promotional literature. More stringent scrutiny and issue of WLs or blacklisting of indulging pharmaceutical companies are mandatory by the regulatory agency to contain the same.

  6. The Rasch Poisson Counts Model for Incomplete Data: An Application of the EM Algorithm.

    Science.gov (United States)

    Jansen, Margo G. H.

    1995-01-01

    The Rasch Poisson counts model is a latent trait model for the situation in which "K" tests are administered to "N" examinees and the test score is a count (repeated number of some event). A mixed model is presented that applies the EM algorithm and that can allow for missing data. (SLD)

  7. A connection between item/subtest regression and the Rasch model

    NARCIS (Netherlands)

    Engelen, Ronald J.H.; Jannarone, Robert J.

    1989-01-01

    The purpose of this paper is to link empirical Bayes methods with two specific topics in item response theory--item/subtest regression, and testing the goodness of fit of the Rasch model--under the assumptions of local independence and sufficiency. It is shown that item/subtest regression results in

  8. Detecting Differential Rater Functioning over Time (DRIFT) Using a Rasch Multi-Faceted Rating Scale Model.

    Science.gov (United States)

    Wolfe, Edward W.; Moulder, Bradley C.; Myford, Carol M.

    This paper describes a class of rater effects that depict rater-by-time interactions. This class of rater effects is referred to as differential rater functioning over time (DRIFT). This article describes several types of DRIFT (primacy/recency, differential centrality/extremism, and practice/fatigue) and Rasch measurement procedures designed to…

  9. Fitting the Mixed Rasch Model to a Reading Comprehension Test: Identifying Reader Types

    Science.gov (United States)

    Baghaei, Purya; Carstensen, Claus H.

    2013-01-01

    Standard unidimensional Rasch models assume that persons with the same ability parameters are comparable. That is, the same interpretation applies to persons with identical ability estimates as regards the underlying mental processes triggered by the test. However, research in cognitive psychology shows that persons at the same trait level may…

  10. An Introduction to Item Response Theory and Rasch Models for Speech-Language Pathologists

    Science.gov (United States)

    Baylor, Carolyn; Hula, William; Donovan, Neila J.; Doyle, Patrick J.; Kendall, Diane; Yorkston, Kathryn

    2011-01-01

    Purpose: To present a primarily conceptual introduction to item response theory (IRT) and Rasch models for speech-language pathologists (SLPs). Method: This tutorial introduces SLPs to basic concepts and terminology related to IRT as well as the most common IRT models. The article then continues with an overview of how instruments are developed…

  11. Performance and Mastery Orientation of High School and University/College Students: A Rasch Perspective

    Science.gov (United States)

    Martin, Andrew J.; Marsh, Herbert W.; Debus, Raymond L.; Malmberg, Lars-Erik

    2008-01-01

    This investigation assesses performance and mastery orientation from a Rasch perspective among high school and university students and provides a complementary approach to the factor analytic methods typical in goal theory research. Data shows that both school and university students are high in mastery orientation relative to performance…

  12. Developing a Rasch Measurement Physical Fitness Scale for Hong Kong Primary School-Aged Students

    Science.gov (United States)

    Yan, Zi; Bond, Trevor G.

    2011-01-01

    The main purpose of this study was to develop a Rasch Measurement Physical Fitness Scale (RMPFS) based on physical fitness indicators routinely used in Hong Kong primary schools. A total of 9,439 records of students' performances on physical fitness indicators, retrieved from the database of a Hong Kong primary school, were used to develop the…

  13. Teater vajab ellujäämiseks värsket dramaturgiat / Jane Rasch ; vahendanud Eva-Liisa Linder

    Index Scriptorium Estoniae

    Rasch, Jane

    2009-01-01

    Taani teatriteadlane Jane Rasch õpetas 10.-14. augustini 2009 Viljandi Kultuuriakadeemias toimunud draamakirjutuskursusel "Ideedest näidendi stsenaariumini". Ka näitekirjanike koolitamisest Taanis jt. Põhjamaades

  14. A Note on the Computation of the Second-Order Derivatives of the Elementary Symmetric Functions in the Rasch Model.

    Science.gov (United States)

    Formann, Anton K.

    1986-01-01

    It is shown that for equal parameters explicit formulas exist, facilitating the application of the Newton-Raphson procedure to estimate the parameters in the Rasch model and related models according to the conditional maximum likelihood principle. (Author/LMO)

  15. Synthetic Peptides to Target Stringent Response-Controlled Virulence in a Pseudomonas aeruginosa Murine Cutaneous Infection Model

    Directory of Open Access Journals (Sweden)

    Daniel Pletzer

    2017-09-01

    Full Text Available Microorganisms continuously monitor their surroundings and adaptively respond to environmental cues. One way to cope with various stress-related situations is through the activation of the stringent stress response pathway. In Pseudomonas aeruginosa this pathway is controlled and coordinated by the activity of the RelA and SpoT enzymes that metabolize the small nucleotide secondary messenger molecule (pppGpp. Intracellular ppGpp concentrations are crucial in mediating adaptive responses and virulence. Targeting this cellular stress response has recently been the focus of an alternative approach to fight antibiotic resistant bacteria. Here, we examined the role of the stringent response in the virulence of P. aeruginosa PAO1 and the Liverpool epidemic strain LESB58. A ΔrelA/ΔspoT double mutant showed decreased cytotoxicity toward human epithelial cells, exhibited reduced hemolytic activity, and caused down-regulation of the expression of the alkaline protease aprA gene in stringent response mutants grown on blood agar plates. Promoter fusions of relA or spoT to a bioluminescence reporter gene revealed that both genes were expressed during the formation of cutaneous abscesses in mice. Intriguingly, virulence was attenuated in vivo by the ΔrelA/ΔspoT double mutant, but not the relA mutant nor the ΔrelA/ΔspoT complemented with either gene. Treatment of a cutaneous P. aeruginosa PAO1 infection with anti-biofilm peptides increased animal welfare, decreased dermonecrotic lesion sizes, and reduced bacterial numbers recovered from abscesses, resembling the phenotype of the ΔrelA/ΔspoT infection. It was previously demonstrated by our lab that ppGpp could be targeted by synthetic peptides; here we demonstrated that spoT promoter activity was suppressed during cutaneous abscess formation by treatment with peptides DJK-5 and 1018, and that a peptide-treated relA complemented stringent response double mutant strain exhibited reduced peptide

  16. Stringent and reproducible tetracycline-regulated transgene expression by site-specific insertion at chromosomal loci with pre-characterised induction characteristics

    Directory of Open Access Journals (Sweden)

    Papanastasiou Antigoni M

    2007-05-01

    Full Text Available Abstract Background The ability to regulate transgene expression has many applications, mostly concerning the analysis of gene function. Desirable induction characteristics, such as low un-induced expression, high induced expression and limited cellular heterogeneity, can be seriously impaired by chromosomal position effects at the site of transgene integration. Many clones may therefore need to be screened before one with optimal induction characteristics is identified. Furthermore, such screens must be repeated for each new transgene investigated, and comparisons between clones with different transgenes is complicated by their different integration sites. Results To circumvent these problems we have developed a "screen and insert" strategy in which clones carrying a transgene for a fluorescent reporter are first screened for those with optimal induction characteristics. Site-specific recombination (SSR is then be used repeatedly to insert any new transgene at the reporter transgene locus of such clones so that optimal induction characteristics are conferred upon it. Here we have tested in a human fibrosarcoma cell line (HT1080 two of many possible implementations of this approach. Clones (e.g. Rht14-10 in which a GFP reporter gene is very stringently regulated by the tetracycline (tet transactivator (tTA protein were first identified flow-cytometrically. Transgenes encoding luciferase, I-SceI endonuclease or Rad52 were then inserted by SSR at a LoxP site adjacent to the GFP gene resulting stringent tet-regulated transgene expression. In clone Rht14-10, increases in expression from essentially background levels (+tet to more than 104-fold above background (-tet were reproducibly detected after Cre-mediated insertion of either the luciferase or the I-SceI transgenes. Conclusion Although previous methods have made use of SSR to integrate transgenes at defined sites, none has effectively combined this with a pre-selection step to identify

  17. Psychometric properties and adaptation of the ASRS in a Spanish sample of patients with substance use disorders: Application of two IRT Rasch models.

    Science.gov (United States)

    Sanchez-Garcia, Manuel; Fernandez-Calderon, Fermin; Carmona-Marquez, Jose; Chico-Garcia, Marilo; Velez-Moreno, Antonio; Perez-Gomez, Lorena

    2015-06-01

    The Adult ADHD Self-Report Scale (ASRS; Kessler et al., 2005) is one of the most extensively used scales to detect attention-deficit hyperactivity disorder (ADHD) in adults. The aim of this work is to analyze the psychometric properties of the 18 ASRS items in people with substance use disorders (SUDs). Furthermore, we aimed to (a) confirm or, if necessary, modify the dichotomization criteria of the items proposed by the authors, and (b) identify the most informative items for a screening version or, when applicable, confirm the use of the 6 items that comprise the initially proposed short version. The ASRS was completed for 170 patients with SUD at the Provincial Unit for Drug Dependence of Huelva, Spain, aged 16 to 78 years. Two Rasch models—the dichotomous Rasch model and the Rating Scale Model (RSM) for polytomous items—were used in the psychometric analysis. The ASRS items fitted the RSM adequately, but the locations of the items along the underlying construct led us to propose new criteria of dichotomization. After analyzing the information function of dichotomized items, we identified 6 items that should integrate a new screening scale. Our dichotomization proposal is different from the original one and takes into account the different weights of the items. The selected screening version showed better metric properties than the other analyzed versions. Future research should test our proposal by using external criteria and to obtain evidences for other populations, cultures, or patient profiles. (c) 2015 APA, all rights reserved).

  18. Towards the development of clinical measures for spinal cord injury based on the International Classification of Functioning, Disability and Health with Rasch analyses.

    Science.gov (United States)

    Ballert, Carolina S; Stucki, Gerold; Biering-Sørensen, Fin; Cieza, Alarcos

    2014-09-01

    To determine whether the International Classification of Functioning, Disability and Health (ICF) categories relevant to spinal cord injury (SCI) can be integrated in clinical measures and to obtain insights to guide their future operationalization. Specific aims are to find out whether the ICF categories relevant to SCI fit a Rasch model taking into consideration the dimensionality found in previous investigations, local item dependencies, or differential item functioning. All second-level ICF categories collected in the Development of ICF Core Sets for SCI project in specialized centers within 15 countries from 2006 through 2008. Secondary data analysis. Adults (N=1048) with SCI from the early postacute and long-term living context. Not applicable. Two unidimensional Rasch analyses: one for the ICF categories from body functions and body structures components and another for the ICF categories from the activities and participation component. Results support good reliability and targeting of the ICF categories in both dimensions. In each dimension, few ICF categories were subject to misfit. Local item dependency was observed between ICF categories of the same chapters. Group effects for age and sex were observed only to a small extent. The validity of ICF categories to develop measures of functioning in SCI for clinical practice and research is to some extent supported. Model adjustments were suggested to further improve their operationalization and psychometrics. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  19. Quality of life in the Danish general population--normative data and validity of WHOQOL-BREF using Rasch and item response theory models

    DEFF Research Database (Denmark)

    Noerholm, V; Groenvold, M; Watt, T

    2004-01-01

    BACKGROUND: The main objective of this study was to investigate the construct validity of the WHOQOL-BREF by use of Rasch and Item Response Theory models and to examine the stability of the model across high/low scoring individuals, gender, education, and depressive illness. Furthermore, the obje......BACKGROUND: The main objective of this study was to investigate the construct validity of the WHOQOL-BREF by use of Rasch and Item Response Theory models and to examine the stability of the model across high/low scoring individuals, gender, education, and depressive illness. Furthermore......, the objective of the study was to estimate the reference data for the quality of life questionnaire WHOQOL-BREF in the general Danish population and in subgroups defined by age, gender, and education. METHODS: Mail-out-mail-back questionnaires were sent to a randomly selected sample of the Danish general...... to multidimensionality, the total score of 26 items fitted neither model. Regression analysis was carried out, showing a level of explained variance of between 10 and 14%. The mean scores of the WHOQOL-BREF are reported as normative data for the general Danish population. CONCLUSION: The profile of the four WHOQOL...

  20. CONSTRUCCIÓN Y VALIDACIÓN DE UNA PRUEBA DE COMPRENSIÓN DE LECTURA MEDIANTE EL MODELO DE RASCH (CONSTRUCTION AND VALIDATION OF A READING COMPREHENSION TEST THOUGH THE RASCH MODEL

    Directory of Open Access Journals (Sweden)

    Solórzano Salas Julieta

    2011-08-01

    Full Text Available Resumen:El presente artículo expone los resultados del diseño y la construcción de una prueba diagnóstica de comprensión de lectura literal e inferencial, para estudiantes de escuelas públicas de III grado de la Educación General Básica, correspondientes a la Dirección Regional de San José, Costa Rica, realizada en el año 2009. Se trabajó con una muestra aleatoria de 406 estudiantes. La prueba está compuesta por 30 ítems, divididos en tres niveles de complejidad (fácil, intermedio y avanzado, según el criterio de personas juezas y los resultados obtenidos en el análisis. Se utilizaron los supuestos teóricos del Modelo de Rasch para el análisis de los resultados sobre confiabilidad y validez de los ítems, así como de la habilidad de las personas. Los resultados evidenciaron un desajuste constante en el 50% del grupo de personas examinadas, así como veinticuatro ítems con una alta confiabilidad (0.98. La media de dificultad de la prueba se ubicó por debajo de la media de habilidad de las personas examinadas. Un 98% del grupo de participantes se ubicó en los niveles de habilidades intermedias y altas, en la resolución de ítems que miden la comprensión de lectura literal e inferencial.Abstract: This paper presents the results of the design and validation of a diagnostic test of literal and inferential reading comprehension was made on 2009. The test was designed for III grade General Basic Education students, Regional Direction of San José, Costa Rica. The study was done with a random sample of 406 students. The test consists of 30 items, divided into three levels of complexity (easy, intermediate and advanced, according to the criteria of expert judges and the results obtained in the analysis. The theoretical assumptions of the Rasch Model were used for the analysis of the results on the reliability and validity of the items, as well as on the ability of the individuals. The results show a continuing gap in 50% of

  1. Accounting for Local Dependence with the Rasch Model: The Paradox of Information Increase.

    Science.gov (United States)

    Andrich, David

    Test theories imply statistical, local independence. Where local independence is violated, models of modern test theory that account for it have been proposed. One violation of local independence occurs when the response to one item governs the response to a subsequent item. Expanding on a formulation of this kind of violation between two items in the dichotomous Rasch model, this paper derives three related implications. First, it formalises how the polytomous Rasch model for an item constituted by summing the scores of the dependent items absorbs the dependence in its threshold structure. Second, it shows that as a consequence the unit when the dependence is accounted for is not the same as if the items had no response dependence. Third, it explains the paradox, known, but not explained in the literature, that the greater the dependence of the constituent items the greater the apparent information in the constituted polytomous item when it should provide less information.

  2. Measuring parental stress in mothers of infants: A Rasch-based construct validity study

    DEFF Research Database (Denmark)

    Nielsen, Tine; Pontoppidan, Maiken; Kristensen, Ingeborg Hedegaard

    Short abstract Becoming a parent is both a rewarding and taxing experience for most parents. Caring for an infant affects stress levels. The Parental Stress Scale (PSS) is a short measure of perceived stress pertaining to the parenting role. The current study examined the psychometric properties...... to the pure Rasch model could be established for the full PSS scale with dichotomized items. After eliminating two items (2 and 11), two subscales measuring different aspect of parental stress; a 9-item scale measuring parental stress and a 7-item scale measuring lack of parental satisfaction (reversed items......) were found each to fit so-called graphical loglinear Rasch models: The parental stress subscale fit a model adjusted for local response dependence between some item pairs, as well as DIF for one item relative to mothers’ level of education and DIF for another item relative to age and educational level...

  3. Sensitivity of Mantel Haenszel Model and Rasch Model as Viewed From Sample Size

    OpenAIRE

    ALWI, IDRUS

    2011-01-01

    The aims of this research is to study the sensitivity comparison of Mantel Haenszel and Rasch Model for detection differential item functioning, observed from the sample size. These two differential item functioning (DIF) methods were compared using simulate binary item respon data sets of varying sample size,  200 and 400 examinees were used in the analyses, a detection method of differential item functioning (DIF) based on gender difference. These test conditions were replication 4 tim...

  4. Quantitative Reasoning in Environmental Science: Rasch Measurement to Support QR Assessment

    Directory of Open Access Journals (Sweden)

    Robert L. Mayes

    2015-07-01

    Full Text Available The ability of middle and high school students to reason quantitatively within the context of environmental science was investigated. A quantitative reasoning (QR learning progression, with associated QR assessments in the content areas of biodiversity, water, and carbon, was developed based on three QR progress variables: quantification act, quantitative interpretation, and quantitative modeling. Diagnostic instruments were developed specifically for the progress variable quantitative interpretation (QI, each consisting of 96 Likert-scale items. Each content version of the instrument focused on three scale levels (macro scale, micro scale, and landscape scale and four elements of QI identified in prior research (trend, translation, prediction, and revision. The QI assessments were completed by 362, 6th to 12th grade students in three U.S. states. Rasch (1960/1980 measurement was used to determine item and person measures for the QI instruments, both to examine validity and reliability characteristics of the instrument administration and inform the evolution of the learning progression. Rasch methods allowed identification of several QI instrument revisions, including modification of specific items, reducing number of items to avoid cognitive fatigue, reconsidering proposed item difficulty levels, and reducing Likert scale to 4 levels. Rasch diagnostics also indicated favorable levels of instrument reliability and appropriate targeting of item abilities to student abilities for the majority of participants. A revised QI instrument is available for STEM researchers and educators.

  5. Spurious Latent Class Problem in the Mixed Rasch Model: A Comparison of Three Maximum Likelihood Estimation Methods under Different Ability Distributions

    Science.gov (United States)

    Sen, Sedat

    2018-01-01

    Recent research has shown that over-extraction of latent classes can be observed in the Bayesian estimation of the mixed Rasch model when the distribution of ability is non-normal. This study examined the effect of non-normal ability distributions on the number of latent classes in the mixed Rasch model when estimated with maximum likelihood…

  6. The implementation of modern digital technology in x-ray medical diagnosis in Republic of Moldova - a stringent necessity

    International Nuclear Information System (INIS)

    Rosca, Andrei

    2011-01-01

    The study includes analyses of current technical state of radiodiagnostic equipment from the Public Medico-Sanitary Institution of Ministry of Health of Republic of Moldova (IMSP MS RM). The traditional radiodiagnostic apparatuses were morally and physically outrun at 96,6% (in regional MSPI - 93,5%), inclusive the dental one - 92,0% (in raional MSPI - 97,2%), X-Ray exam -100%, mobile - 84,1% etc. The exploitation of the traditional radiodiagnostic apparatuses with high degree of physical and moral wear essentially diminished the quality of profile investigation, creates premises for diagnostic error perpetrating, increase the collective ionizing irradiation of population etc. In recent years the subvention of MSPI HM RM with digital radiodiagnostic equipment was started. This process is very hard unfold because of grave socio-economic crises in Republic of Moldova. Despite these obstacles the subvention of MSPI HM RM with digital equipment represents a stringent necessity and a time request.

  7. The mechanism of heterogeneous beta-lactam resistance in MRSA: key role of the stringent stress response.

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    Choonkeun Kim

    Full Text Available All methicillin resistant S. aureus (MRSA strains carry an acquired genetic determinant--mecA or mecC--which encode for a low affinity penicillin binding protein -PBP2A or PBP2A'--that can continue the catalysis of peptidoglycan transpeptidation in the presence of high concentrations of beta-lactam antibiotics which would inhibit the native PBPs normally involved with the synthesis of staphylococcal cell wall peptidoglycan. In contrast to this common genetic and biochemical mechanism carried by all MRSA strains, the level of beta-lactam antibiotic resistance shows a very wide strain to strain variation, the mechanism of which has remained poorly understood. The overwhelming majority of MRSA strains produce a unique--heterogeneous--phenotype in which the great majority of the bacteria exhibit very poor resistance often close to the MIC value of susceptible S. aureus strains. However, cultures of such heterogeneously resistant MRSA strains also contain subpopulations of bacteria with extremely high beta-lactam MIC values and the resistance level and frequency of the highly resistant cells in such strain is a characteristic of the particular MRSA clone. In the study described in this communication, we used a variety of experimental models to understand the mechanism of heterogeneous beta-lactam resistance. Methicillin-susceptible S. aureus (MSSA that received the mecA determinant in the laboratory either on a plasmid or in the form of a chromosomal SCCmec cassette, generated heterogeneously resistant cultures and the highly resistant subpopulations that emerged in these models had increased levels of PBP2A and were composed of bacteria in which the stringent stress response was induced. Each of the major heterogeneously resistant clones of MRSA clinical isolates could be converted to express high level and homogeneous resistance if the growth medium contained an inducer of the stringent stress response.

  8. Global energy scenarios meeting stringent CO2 constraints - cost-effective fuel choices in the transportation sector

    International Nuclear Information System (INIS)

    Azar, Christian; Lindgren, Kristian; Andersson, B.A.

    2003-01-01

    The purpose of this paper is to assess fuel choices in the transportation sector under stringent global carbon constraints. Three key questions are asked: (i) when is it cost-effective to carry out the transition away from gasoline/diesel; (ii) to which fuel is it cost-effective to shift; and (iii) in which sector is biomass most cost-effectively used? These questions are analyzed using a global energy systems model (GET 1.0), with a transportation module, where vehicle costs (fuel cell, reformer and storage tank), infrastructure and primary energy availability are treated explicitly. The model is run under the assumption that atmospheric concentrations of CO 2 should be stabilized at 400 ppm. Three main results emerge: (i) despite the stringent CO 2 constraints, oil-based fuels remain dominant in the transportation sector over the next 50 years; and (ii) once a transition towards alternative fuels takes place, the preferred choice of fuel is hydrogen, even if we assume that hydrogen fuel cell vehicles are substantially more costly than methanol fuel cell vehicles. There may, under some circumstances, be a transient period of several decades with a significant share of methanol in the transportation sector. (iii) Biomass is most cost-effectively used in the heat and process heat sectors. If carbon sequestration from biomass is allowed, biomass is primarily used for hydrogen generation since small-scale heat applications are not suitable for carbon sequestration. Detailed sensitivity analyses show that these results are robust with respect to several parameters. Some policy conclusions are drawn

  9. Validation of a Targeted Peer Relations Scale for Adolescents Treated for Substance Use Disorder: An Application of Rasch Modeling

    Directory of Open Access Journals (Sweden)

    James R. Ciesla

    2011-01-01

    Full Text Available The objective of this research is to use item response theory (IRT to validate a 14-item peer relations scale for use in the adolescent treatment population. Subjects are 509 adolescents discharged from substance abuse treatment from 2004–2009. The person reliability is 0.76 and the Cronbach's alpha person raw score reliability is 0.93 both indicating the scale is a strong metric. The item reliability of 0.99 is high showing the model is reliable. The real separation (8.49 meaning items are placed on the Rasch “ruler” with about eight levels of importance identified. The mean-square statistics of the infit and outfit values were between 0.5 and 1.5 for the items indicating a low level of randomness and thus unidimensionality of the scale. Inspection of a Wright Item Map shows the hierarchical structure of the scale with a moderate degree of inter-item spread. The analysis shows the scale is a reliable unidimensional metric.

  10. Development and Validation of a Health and Work Survey Based on the Rasch Model among Portuguese Workers.

    Science.gov (United States)

    Barros, Carla; Cunha, Liliana; Baylina, Pilar; Oliveira, Alexandra; Rocha, Álvaro

    2017-05-01

    The purpose of this study was to develop the Health and Work Survey (INSAT) and examine the validity of the discomfort rating scale. Data were collected from 706 Portuguese workers from six economic sectors with the support of the Health and Work Survey (INSAT - Inquérito Saúde e Trabalho). The INSAT is a self-administered questionnaire to assessing working conditions, health and wellbeing, and to provide information to the occupational health systems in the organisations. For the survey instrument validation, the Rasch Partial Credit Model (PCM) was used to analyse item fit statistics. From the application of PCM, Person Separation Reliability was obtained (0.8761) and the value can be considered very good (>0.8). From the statistical analysis, the Overall Model fit information, given by Outfit Mean square/Infit Mean square, is between 0.5 and 1.5, meaning "Productive for measurement" and "acceptable fit overall". The INSAT items can generate predictable response patterns. We recommend that the INSAT discomfort rating scale and some other items should be reviewed in future works. In any event, this tool proves to be useful in assessing the relationship between work and health and in evaluating key main risk factors, helping to prevent problems and improving occupational health systems.

  11. Meeting the requirements of both classroom-based and systemic assessment of mathematics proficiency: The potential of Rasch measurement theory

    Directory of Open Access Journals (Sweden)

    Tim Dunne

    2012-11-01

    Full Text Available The challenges inherent in assessing mathematical proficiency depend on a number of factors, amongst which are an explicit view of what constitutes mathematical proficiency, an understanding of how children learn and the purpose and function of teaching. All of these factors impact on the choice of approach to assessment. In this article we distinguish between two broad types of assessment, classroom-based and systemic assessment. We argue that the process of assessment informed by Rasch measurement theory (RMT can potentially support the demands of both classroom-based and systemic assessment, particularly if a developmental approach to learning is adopted, and an underlying model of developing mathematical proficiency is explicit in the assessment instruments and their supporting material. An example of a mathematics instrument and its analysis which illustrates this approach, is presented. We note that the role of assessment in the 21st century is potentially powerful. This influential role can only be justified if the assessments are of high quality and can be selected to match suitable moments in learning progress and the teaching process. Users of assessment data must have sufficient knowledge and insight to interpret the resulting numbers validly, and have sufficient discernment to make considered educational inferences from the data for teaching and learning responses.

  12. Meeting the requirements of both classroom-based and systemic assessment of mathematics proficiency: The potential of Rasch measurement theory

    Directory of Open Access Journals (Sweden)

    Tim Dunne

    2012-10-01

    Full Text Available The challenges inherent in assessing mathematical proficiency depend on a number of factors, amongst which are an explicit view of what constitutes mathematical proficiency, an understanding of how children learn and the purpose and function of teaching. All of these factors impact on the choice of approach to assessment. In this article we distinguish between two broad types of assessment, classroom-based and systemic assessment. We argue that the process of assessment informed by Rasch measurement theory (RMT can potentially support the demands of both classroom-based and systemic assessment, particularly if a developmental approach to learning is adopted, and an underlying model of developing mathematical proficiency is explicit in the assessment instruments and their supporting material. An example of a mathematics instrument and its analysis which illustrates this approach, is presented. We note that the role of assessment in the 21st century is potentially powerful. This influential role can only be justified if the assessments are of high quality and can be selected to match suitable moments in learning progress and the teaching process. Users of assessment data must have sufficient knowledge and insight to interpret the resulting numbers validly, and have sufficient discernment to make considered educational inferences from the data for teaching and learning responses.

  13. Nuclear controls are stringent

    International Nuclear Information System (INIS)

    Sonnekus, D.

    1983-01-01

    The peace-time application of nuclear power in South Africa, the organisations concerned and certain provisions laid down by the Act on Nuclear Energy, aimed at safeguarding the general public, are discussed

  14. Validation of the Danish version of the McGill Ingestive Skills Assessment using classical test theory and the Rasch model

    DEFF Research Database (Denmark)

    Hansen, Tina; Lambert, Heather C; Faber, Jens

    2012-01-01

    Purpose: The study aimed to validate the Danish version of the Canadian the "McGill Ingestive Skills Assessment" (MISA-DK) for measuring dysphagia in frail elders. Method: One-hundred and ten consecutive older medical patients were recruited to the study. Reliability was assessed by internal...... consistency (Chronbach's alpha). External construct validity (convergent and known-groups validity) was evaluated against theoretical constructs assessing the complex concept of ingestive skills. Internal construct validity was tested using Rasch analysis. Results: High internal consistency reliability......), p¿=¿0.424) and unidimensionality of the MISA-DK was confirmed after resolving disordered thresholds for 11 items and adjustment of local dependency. Conclusion: The psychometric properties of the MISA-DK equal the original Canadian version. Assessment of internal construct validity indicated...

  15. Are More Stringent NCLB State Accountability Systems Associated with Better Student Outcomes? An Analysis of NAEP Results across States

    Science.gov (United States)

    Wei, Xin

    2012-01-01

    This study developed a comprehensive measure of the stringency level of NCLB states' accountability systems, including the strength of their annual measurable objectives, confidence intervals, performance indexing, retesting, minimum subgroup size, and the difficulty levels of proficiency standards. This study related accountability stringency in…

  16. Validating The ISO 9000 Construct of Measurement Instrument Through Application of RASCH Model

    Directory of Open Access Journals (Sweden)

    Rohaizah Saad

    2012-01-01

    Full Text Available There are numerous researches conducted on the issues related to ISO 9001 quality management system. Among the issue is the impact of the ISO 9001 quality management system implementation on the performance of the organization. However the findings from the research appeared as inconclusive. Few literature suggest that the inconclusive result may due to the level of ISO 9000 implementation therefore further research is required. Generally the data collected for these types of researches are through mailed questionnaires and analyzed it using SPSS and SEM. In line with that this study also developed questionnaires correspond to a 5 point Likert to assess the implementation of ISO 9000 in the organization. As a result 231 items are identified within five dimensions. The five dimensions are derived from ISO 9001 and ISO 9004 quality management standards requirement and guidelines. Among the dimensions are management responsibility, resource management, product realization, measurement improvement and innovation and organizational performance. The questionnaires are sent to 78 automotive based companies located in the Northern region of Peninsular Malaysia. 19 questionnaires were returned and used as pilot test to validate and calibrate the instrument. The responds from the organization are tabulated and run in WinSteps software for the purpose of validating and calibrating the instrument by implementing the Rasch ‘quality control’ and reduction of items. Not all the outfit items are removed from the instruments, Rasch Model did provide room for the researcher to make decision either to remove or not those outfit items. In this study those outfit items need to be corrected in order to ensure that the instrument is reliable and fit to measure the performance of the organization. As a result 68 items are removed from the questionnaires.Keyword: rasch model, ISO 9001, quality control and items reduction.

  17. Using Rasch Modeling to Re-Evaluate Rapid Malaria Diagnosis Test Analyses

    Directory of Open Access Journals (Sweden)

    Dawit G. Ayele

    2014-06-01

    Full Text Available The objective of this study was to demonstrate the use of the Rasch model by assessing the appropriateness of the demographic, social-economic and geographic factors in providing a total score in malaria RDT in accordance with the model’s expectations. The baseline malaria indicator survey was conducted in Amhara, Oromiya and Southern Nation Nationalities and People (SNNP regions of Ethiopia by The Carter Center in 2007. The result shows high reliability and little disordering of thresholds with no evidence of differential item functioning.

  18. Assessing Pre-Service Physics Teachers’ Energy Literacy: An Application of Rasch measurement

    Science.gov (United States)

    Yusup, M.; Setiawan, A.; Rustaman, N. Y.; Kaniawati, I.

    2017-09-01

    This paper aims to present a summary of pre-service physics teachers’ responses on energy literacy assessment. A total of 123 pre-service physics teacher in first through third year of education participated. Data were analyzed using Rasch modeling. Research findings indicate that pre-service physics teachers show their low self-system toward energy conservation. They were also still lack of metacognitive and cognitive competencies. These finding provide information for the future development of curriculum, teaching and learning that can improve pre-service physics teachers’ energy literacy.

  19. Are Dutch residents ready for a more stringent policy to enhance the energy performance of their homes?

    International Nuclear Information System (INIS)

    Middelkoop, Manon van; Vringer, Kees; Visser, Hans

    2017-01-01

    Investments in the energy performance of houses offer good prospects for reducing energy consumption and CO 2 emissions. However, people are not easily convinced of the need to take measures to improve the energy performance of their houses, even when financial benefits outweigh the costs. This article analyses the factors that influence the decision for improving the energy performance of existing homes, including policy instruments. Subsequently, the article provides policy suggestions on how to stimulate energy performance improvements. Both owners and tenants (50–70%) support government policy on energy performance improvements to existing homes. Nevertheless, people also have strong feelings of autonomy regarding their homes. Our results underline the importance of well-informed and competent decision-makers. Introducing the use of Energy Performance Certificates (EPCs) into the tax system for energy and residential buildings might therefore be an effective way to increase the interest of owners in the EPC, improve the use and effect of this informative instrument, and make the first step towards bridging the tension between autonomy and more stringent instruments.

  20. Blooms' separation of the final exam of Engineering Mathematics II: Item reliability using Rasch measurement model

    Science.gov (United States)

    Fuaad, Norain Farhana Ahmad; Nopiah, Zulkifli Mohd; Tawil, Norgainy Mohd; Othman, Haliza; Asshaari, Izamarlina; Osman, Mohd Hanif; Ismail, Nur Arzilah

    2014-06-01

    In engineering studies and researches, Mathematics is one of the main elements which express physical, chemical and engineering laws. Therefore, it is essential for engineering students to have a strong knowledge in the fundamental of mathematics in order to apply the knowledge to real life issues. However, based on the previous results of Mathematics Pre-Test, it shows that the engineering students lack the fundamental knowledge in certain topics in mathematics. Due to this, apart from making improvements in the methods of teaching and learning, studies on the construction of questions (items) should also be emphasized. The purpose of this study is to assist lecturers in the process of item development and to monitor the separation of items based on Blooms' Taxonomy and to measure the reliability of the items itself usingRasch Measurement Model as a tool. By using Rasch Measurement Model, the final exam questions of Engineering Mathematics II (Linear Algebra) for semester 2 sessions 2012/2013 were analysed and the results will provide the details onthe extent to which the content of the item providesuseful information about students' ability. This study reveals that the items used in Engineering Mathematics II (Linear Algebra) final exam are well constructed but the separation of the items raises concern as it is argued that it needs further attention, as there is abig gap between items at several levels of Blooms' cognitive skill.

  1. Controlling response dependence in the measurement of change using the Rasch model.

    Science.gov (United States)

    Andrich, David

    2017-01-01

    The advantages of using person location estimates from the Rasch model over raw scores for the measurement of change using a common test include the linearization of scores and the automatic handling of statistical properties of repeated measurements. However, the application of the model requires that the responses to the items are statistically independent in the sense that the specific responses to the items on the first time of testing do not affect the responses at a second time. This requirement implies that the responses to the items at both times of assessment are governed only by the invariant location parameters of the items at the two times of testing and the location parameters of each person each time. A specific form of dependence that is pertinent when the same items are used is when the observed response to an item at the second time of testing is affected by the response to the same item at the first time, a form of dependence which has been referred to as response dependence. This paper presents the logic of applying the Rasch model to quantify, control and remove the effect of response dependence in the measurement of change when the same items are used on two occasions. The logic is illustrated with four sets of simulation studies with dichotomous items and with a small example of real data. It is shown that the presence of response dependence can reduce the evidence of change, a reduction which may impact interpretations at the individual, research, and policy levels.

  2. Using the Rasch measurement model to design a report writing assessment instrument.

    Science.gov (United States)

    Carlson, Wayne R

    2013-01-01

    This paper describes how the Rasch measurement model was used to develop an assessment instrument designed to measure student ability to write law enforcement incident and investigative reports. The ability to write reports is a requirement of all law enforcement recruits in the state of Michigan and is a part of the state's mandatory basic training curriculum, which is promulgated by the Michigan Commission on Law Enforcement Standards (MCOLES). Recently, MCOLES conducted research to modernize its training and testing in the area of report writing. A structured validation process was used, which included: a) an examination of the job tasks of a patrol officer, b) input from content experts, c) a review of the professional research, and d) the creation of an instrument to measure student competency. The Rasch model addressed several measurement principles that were central to construct validity, which were particularly useful for assessing student performances. Based on the results of the report writing validation project, the state established a legitimate connectivity between the report writing standard and the essential job functions of a patrol officer in Michigan. The project also produced an authentic instrument for measuring minimum levels of report writing competency, which generated results that are valid for inferences of student ability. Ultimately, the state of Michigan must ensure the safety of its citizens by licensing only those patrol officers who possess a minimum level of core competency. Maintaining the validity and reliability of both the training and testing processes can ensure that the system for producing such candidates functions as intended.

  3. Using the Bootstrap Method to Evaluate the Critical Range of Misfit for Polytomous Rasch Fit Statistics.

    Science.gov (United States)

    Seol, Hyunsoo

    2016-06-01

    The purpose of this study was to apply the bootstrap procedure to evaluate how the bootstrapped confidence intervals (CIs) for polytomous Rasch fit statistics might differ according to sample sizes and test lengths in comparison with the rule-of-thumb critical value of misfit. A total of 25 simulated data sets were generated to fit the Rasch measurement and then a total of 1,000 replications were conducted to compute the bootstrapped CIs under each of 25 testing conditions. The results showed that rule-of-thumb critical values for assessing the magnitude of misfit were not applicable because the infit and outfit mean square error statistics showed different magnitudes of variability over testing conditions and the standardized fit statistics did not exactly follow the standard normal distribution. Further, they also do not share the same critical range for the item and person misfit. Based on the results of the study, the bootstrapped CIs can be used to identify misfitting items or persons as they offer a reasonable alternative solution, especially when the distributions of the infit and outfit statistics are not well known and depend on sample size. © The Author(s) 2016.

  4. Comparing the NIS vs. MRC and INCAT sensory scale through Rasch analyses.

    Science.gov (United States)

    Draak, Thomas H P; Vanhoutte, Els K; van Nes, Sonja I; Gorson, Kenneth C; Van der Pol, W-Ludo; Notermans, Nicolette C; Nobile-Orazio, Eduardo; Lewis, Richard A; Léger, Jean-Marc; Van den Bergh, Peter Y K; Lauria, Giuseppe; Bril, Vera; Katzberg, Hans; Lunn, Michael P T; Pouget, Jean; van der Kooi, Anneke J; Hahn, Angelika F; van den Berg, Leonard H; van Doorn, Pieter A; Cornblath, David R; Faber, Catharina G; Merkies, Ingemar S J

    2015-09-01

    We performed a comparison between Neuropathy Impairment Scale-sensory (NISs) vs. the modified Inflammatory Neuropathy Cause and Treatment sensory scale (mISS), and NIS-motor vs. the Medical Research Council sum score in patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and IgM monoclonal gammopathy of undetermined significance-related polyneuropathy (MGUSP). The ordinal data were subjected to Rasch analyses, creating Rasch-transformed (RT)-intervals for all measures. Comparison between measures was based on validity/reliability with an emphasis on responsiveness (using the patient's level of change related to the individually obtained varying SE for minimum clinically important difference). Eighty stable patients (GBS: 30, CIDP: 30, and MGUSP: 20) were assessed twice (entry: two observers; 2-4 weeks later: one observer), and 137 newly diagnosed or relapsing patients (GBS: 55, CIDP: 59, and IgM-MGUSP: 23) were serially examined with 12 months follow-up. Data modifications were needed to improve model fit for all measures. The sensory and motor scales demonstrated approximately equal and acceptable validity and reliability scores. Responsiveness scores were poor but slightly higher in RT-mISS compared to RT-NISs. Responsiveness was equal for the RT-motor scales, but higher in GBS compared to CIDP; responsiveness was poor in patients with MGUSP, suggesting a longer duration of follow-up in the latter group of patients. © 2015 Peripheral Nerve Society.

  5. Measuring Engagement in Later Life Activities: Rasch-Based Scenario Scales for Work, Caregiving, Informal Helping, and Volunteering

    Science.gov (United States)

    Ludlow, Larry H.; Matz-Costa, Christina; Johnson, Clair; Brown, Melissa; Besen, Elyssa; James, Jacquelyn B.

    2014-01-01

    The development of Rasch-based "comparative engagement scenarios" based on Guttman's facet theory and sentence mapping procedures is described. The scenario scales measuring engagement in work, caregiving, informal helping, and volunteering illuminate the lived experiences of role involvement among older adults and offer multiple…

  6. Developing a Measure of Therapist Adherence to Contingency Management: An Application of the Many-Facet Rasch Model

    Science.gov (United States)

    Chapman, Jason E.; Sheidow, Ashli J.; Henggeler, Scott W.; Halliday-Boykins, Colleen A.; Cunningham, Phillippe B.

    2008-01-01

    A unique application of the Many-Facet Rasch Model (MFRM) is introduced as the preferred method for evaluating the psychometric properties of a measure of therapist adherence to Contingency Management (CM) treatment of adolescent substance use. The utility of psychometric methods based in Classical Test Theory was limited by complexities of the…

  7. More on the Computation of Higher-Order Derivatives of the Elementary Symmetric Functions in the Rasch Model.

    Science.gov (United States)

    Liou, Michelle

    1994-01-01

    A recursive equation is proposed for computing higher order derivatives of elementary symmetric functions in the Rasch model. A simulation study indicates a small loss in accuracy for the proposed formula compared to Gustafsson's sum algorithm (1980) for computing higher order derivatives when tests contain 60 items or less. (SLD)

  8. Stringently Defined Otitis Prone Children Demonstrate Deficient Naturally Induced Mucosal Antibody Response toMoraxella catarrhalisProteins.

    Science.gov (United States)

    Ren, Dabin; Murphy, Timothy F; Lafontaine, Eric R; Pichichero, Michael E

    2017-01-01

    Moraxella catarrhalis ( Mcat ) is a prominent mucosal pathogen causing acute otitis media (AOM). We studied Mcat nasopharyngeal (NP) colonization, AOM frequency and mucosal antibody responses to four vaccine candidate Mcat proteins: outer membrane protein (OMP) CD, oligopeptide permease (Opp) A, hemagglutinin (Hag), and Pilin A clade 2 (PilA2) from stringently defined otitis prone (sOP) children, who experience the greatest burden of disease, compared to non-otitis prone (NOP) children. sOP children had higher NP colonization of Mcat (30 vs. 22%, P  = 0.0003) and Mcat -caused AOM rates (49 vs. 24%, P  P  P  = 0.018), Hag (IgG and IgA, both P  P  P  = 0.039) and PilA2 ( P  = 0.0076), and IgA to OMP CD ( P  = 0.010), OppA ( P  = 0.030), and PilA2 ( P  = 0.043) were associated with lower carriage of Mcat in NOP but not sOP children. Higher levels of mucosal IgG to OMP CD ( P  = 0.0070) and Hag ( P  = 0.0003), and IgA to Hag ( P  = 0.0067) at asymptomatic colonization than those at onset of AOM were associated with significantly lower rate of Mcat NP colonization progressing to AOM in NOP compared to sOP children (3 vs. 26%, P  NP colonization and NP colonization progressing to Mcat -caused AOM. Enhancing Mcat antigen-specific mucosal immune responses to levels higher than achieved by natural exposure will be necessary to prevent AOM in sOP children.

  9. Stringent constraints on the dark matter annihilation cross section from subhalo searches with the Fermi Gamma-Ray Space Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Berlin, Asher; Hooper, Dan

    2014-01-01

    The dark matter halo of the Milky Way is predicted to contain a very large number of smaller subhalos. As a result of the dark matter annihilations taking place within such objects, the most nearby and massive subhalos could appear as point-like or spatially extended gamma-ray sources, without observable counterparts at other wavelengths. In this paper, we use the results of the Aquarius simulation to predict the distribution of nearby subhalos, and compare this to the characteristics of the unidentified gamma-ray sources observed by the Fermi Gamma-Ray Space Telescope. Focusing on the brightest high latitude sources, we use this comparison to derive limits on the dark matter annihilation cross section. For dark matter particles lighter than ~200 GeV, the resulting limits are the strongest obtained to date, being modestly more stringent than those derived from observations of dwarf galaxies or the Galactic Center. We also derive independent limits based on the lack of unidentified gamma-ray sources with discernible spatial extension, but these limits are a factor of ~2-10 weaker than those based on point-like subhalos. Lastly, we note that four of the ten brightest high-latitude sources exhibit a similar spectral shape, consistent with 30-60 GeV dark matter particles annihilating to b quarks with an annihilation cross section on the order of sigma v ~ (5-10) x 10^-27 cm^3/s, or 8-10 GeV dark matter particles annihilating to taus with sigma v ~ (2.0-2.5) x 10^-27 cm^3/s.

  10. Rasch Measurement in Language Research: Creating the Foreign Language Classroom Anxiety Inventory

    Directory of Open Access Journals (Sweden)

    Miranda J. Walker

    2014-11-01

    Full Text Available The purpose of this study was to construct a new scale for measuring foreign language classroom anxiety (FLCA. It begun with the creation of an extended item pool generated by qualitative methods. Subsequent Rasch and semantic analyses led to the final 18-item Foreign Language Classroom Anxiety Inventory (FLCAI. In comparison with the Foreign Language Classroom Anxiety Scale (FLCAS, the FLCAI demonstrated more convincing evidence of unidimensionality and the optimal 5-point Likert scale functioned better. The FLCAI, while 55% the length of the FLCAS, thus more practical for classroom practitioners to administer and analyse, maintains its psychometric properties and covers a wider range on the construct continuum thus improving the degree of validity of the instrument. Finally, test anxiety was shown to be a component of FLCA.

  11. El modelo de rasch en dirección de operaciones

    Directory of Open Access Journals (Sweden)

    Lidia Sanchez

    2012-11-01

    Full Text Available Durante décadas, en el área de Dirección de Operaciones, se ha destacado la necesidad de un acercamiento entre el mundo académico y el profesional, reclamando la realización de estudios empíricos que aporten soluciones prácticas a los profesionales. De ahí que durante los últimos años se hayan producido dos fenómenos clave: la convergencia entre los temas objeto de investigación y los temas de interés para las empresas; y un aumento en el  número de estudios empíricos realizados.Ahora bien, otro factor importantísimo a la hora de aportar conocimientos prácticos a la disciplina es la herramienta o metodología aplicada. Por ello, el desarrollo de nuevas herramientas o la aplicación de otras ya existentes en otros campos es un tema interesante. Es en este punto donde adquiere importancia la Metodología de Rasch.Esta técnica ha sido tradicionalmente utilizada en disciplinas tales como la Psicología o la Medicina. Sin embargo, ya hace algunos años, ha comenzado a utilizarse en otras áreas de conocimiento, entre ellas, el área de Administración y Dirección de Empresas. No obstante, su aplicación al área concreta de Operaciones es escasa y, por ello, las posibilidades de desarrollo e investigaciones futuras son numerosas.La Metodología de Rasch, útil para el diseño y la explotación de encuestas, se basa en tres principios, unidimensionalidad, aditividad e invarianza, y permite obtener medidas objetivas a partir del análisis de variables categóricas. Entre sus múltiples aplicaciones destacamos las siguientes: análisis de la viabilidad y fiabilidad globales, análisis de la unidimensionalidad del constructo, análisis de escalas del cuestionario, priorización (ordenación de los ítems y/o de los sujetos, análisis DAFO… Es, por lo tanto, una metodología muy rica con multitud de posibilidades para su aplicación en la disciplina.Dado su incipiente desarrollo en esta área de conocimiento el objetivo de este

  12. Gendered language attitudes: exploring language as a gendered construct using Rasch measurement theory.

    Science.gov (United States)

    Knisely, Kris A; Wind, Stefanie A

    2015-01-01

    Gendered language attitudes (GLAs) are gender-based perceptions of language varieties based on connections between gender-related and linguistic characteristics of individuals, including the perception of language varieties as possessing degrees of masculinity and femininity. This study combines substantive theory about language learning and gender with a model based on Rasch measurement theory to explore the psychometric properties of a new measure of GLAs. Findings suggest that GLAs is a unidimensional construct and that the items used can be used to describe differences among students in terms of the strength of their GLAs. Implications for research, theory, and practice are discussed. Special emphasis is given to the teaching and learning of languages.

  13. Aligning physical elements with persons' attitude: an approach using Rasch measurement theory

    International Nuclear Information System (INIS)

    Camargo, F R; Henson, B

    2013-01-01

    Affective engineering uses mathematical models to convert the information obtained from persons' attitude to physical elements into an ergonomic design. However, applications in the domain have not in many cases met measurement assumptions. This paper proposes a novel approach based on Rasch measurement theory to overcome the problem. The research demonstrates that if data fit the model, further variables can be added to a scale. An empirical study was designed to determine the range of compliance where consumers could obtain an impression of a moisturizer cream when touching some product containers. Persons, variables and stimulus objects were parameterised independently on a linear continuum. The results showed that a calibrated scale preserves comparability although incorporating further variables

  14. Uso del modelo de Rasch para poner en la misma escala las puntuaciones de distintos tests

    Directory of Open Access Journals (Sweden)

    Gerardo Prieto-Adánez

    2003-01-01

    Full Text Available Los usuarios de los tests tienen que poner en una escala común las puntuaciones de distintos instrumentos en varias situaciones prácticas, tales como la evaluación académica, la selección de personal, los estudios acerca del cambio de un atributo psicológico o educativo, la construcción de bancos de ítems, la validación intercultural de tests y los estudios sobre el funcionamiento diferencial de los ítems. Situar en una escala común las puntuaciones de diferentes tests es una de las principales aplicaciones del modelo de Rasch. En este artículo, mostramos el proceso de equiparación de dos tests (diseño, análisis de datos e interpretación usando como anclaje un conjunto de ítems comunes.

  15. Exploring students’ perceived and actual ability in solving statistical problems based on Rasch measurement tools

    Science.gov (United States)

    Azila Che Musa, Nor; Mahmud, Zamalia; Baharun, Norhayati

    2017-09-01

    One of the important skills that is required from any student who are learning statistics is knowing how to solve statistical problems correctly using appropriate statistical methods. This will enable them to arrive at a conclusion and make a significant contribution and decision for the society. In this study, a group of 22 students majoring in statistics at UiTM Shah Alam were given problems relating to topics on testing of hypothesis which require them to solve the problems using confidence interval, traditional and p-value approach. Hypothesis testing is one of the techniques used in solving real problems and it is listed as one of the difficult concepts for students to grasp. The objectives of this study is to explore students’ perceived and actual ability in solving statistical problems and to determine which item in statistical problem solving that students find difficult to grasp. Students’ perceived and actual ability were measured based on the instruments developed from the respective topics. Rasch measurement tools such as Wright map and item measures for fit statistics were used to accomplish the objectives. Data were collected and analysed using Winsteps 3.90 software which is developed based on the Rasch measurement model. The results showed that students’ perceived themselves as moderately competent in solving the statistical problems using confidence interval and p-value approach even though their actual performance showed otherwise. Item measures for fit statistics also showed that the maximum estimated measures were found on two problems. These measures indicate that none of the students have attempted these problems correctly due to reasons which include their lack of understanding in confidence interval and probability values.

  16. The Val30Met familial amyloid polyneuropathy specific Rasch-built overall disability scale (FAP-RODS(©) ).

    Science.gov (United States)

    Pruppers, Mariëlle H J; Merkies, Ingemar S J; Faber, Catharina G; Da Silva, Ana M; Costa, Vanessa; Coelho, Teresa

    2015-09-01

    Familial amyloid polyneuropathy (FAP) is a chronic debilitating multi-organic disorder, mainly assessed using ordinal-based impairment measures. To date, no outcome measure at the activity and participation level has been constructed in FAP. The current study aimed to design an interval activity/participation scale for FAP through Rasch methodology. A preliminary FAP Rasch-built overall disability scale (pre-FAP-RODS) containing 146 activity/participation items was assessed twice (interval: 2-4 week; test-retest reliability) in 248 patients with Val30Met FAP examined in Porto, Portugal, of which 65.7% have received liver transplantation. An ordinal-based 24-item FAP-symptoms inventory questionnaire (FAP-SIQ) was also assessed (validity purposes). The pre-FAP-RODS and FAP-SIQ data were subjected to Rasch analyses. The pre-FAP-RODS did not meet model's expectations. On the basis of requirements such as misfit statistics, differential item functioning, and local dependency, items were systematically removed until a final 34-item FAP-RODS(©) was constructed fulfilling all Rasch requirements. Acceptable reliability/validity scores were demonstrated. In conclusion, the 34-item FAP-RODS(©) is a disease-specific interval measure suitable for detecting activity and participation restrictions in patients with FAP. The use of the FAP-RODS(©) is recommended for future international clinical trials in patients with Val30Met FAP determining its responsiveness and its cross-cultural validation. Its expansion to other forms of FAP should also be focus of future clinical studies. © 2015 Peripheral Nerve Society.

  17. Exploring differential item functioning (DIF) with the Rasch model: a comparison of gender differences on eighth grade science items in the United States and Spain.

    Science.gov (United States)

    Babiar, Tasha Calvert

    2011-01-01

    Traditionally, women and minorities have not been fully represented in science and engineering. Numerous studies have attributed these differences to gaps in science achievement as measured by various standardized tests. Rather than describe mean group differences in science achievement across multiple cultures, this study focused on an in-depth item-level analysis across two countries: Spain and the United States. This study investigated eighth-grade gender differences on science items across the two countries. A secondary purpose of the study was to explore the nature of gender differences using the many-faceted Rasch Model as a way to estimate gender DIF. A secondary analysis of data from the Third International Mathematics and Science Study (TIMSS) was used to address three questions: 1) Does gender DIF in science achievement exist? 2) Is there a relationship between gender DIF and characteristics of the science items? 3) Do the relationships between item characteristics and gender DIF in science items replicate across countries. Participants included 7,087 eight grade students from the United States and 3,855 students from Spain who participated in TIMSS. The Facets program (Linacre and Wright, 1992) was used to estimate gender DIF. The results of the analysis indicate that the content of the item seemed to be related to gender DIF. The analysis also suggests that there is a relationship between gender DIF and item format. No pattern of gender DIF related to cognitive demand was found. The general pattern of gender DIF was similar across the two countries used in the analysis. The strength of item-level analysis as opposed to group mean difference analysis is that gender differences can be detected at the item level, even when no mean differences can be detected at the group level.

  18. The optimal achievement model and underachievement in Hong Kong: an application of the Rasch model

    Directory of Open Access Journals (Sweden)

    SHANE N. PHILLIPSON

    2008-06-01

    Full Text Available Termed the optimal achievement model, a new method for the estimation of underachievement relies on measuring student potential (P and achievement (A using Rasch models and calculating an achievement index, IA, for each individual. This study extends a previous report (Phillipson & Tse, 2007 that estimated the proportion of Hong Kong students in Primary 5 to now include a sample of students from Primary 3 (n = 1406, Secondary 1 (n = 756 and Secondary 3 (n = 578, across six districts of Hong Kong. The students were administered a standardized test of mathematical achievement and the Ravens Progressive Matrices Test. Using the optimal achievement model, estimates of underachievement at six percentile bands showed that the proportion of students who were underachieving ranged from 10 % at the 50-59th percentile band up to 30 % at the >95th percentile band for Primary 3, Primary 5 and Secondary 1 students, and 50 % of Secondary 3 students. The estimation of IA at the level of the individual allows the researcher the possibility to directly study the interaction of the environment on student potential.

  19. La variable latente calidad medida a través del modelo de Rasch.

    Directory of Open Access Journals (Sweden)

    Guerrero, Mª M.

    1997-01-01

    Full Text Available La obtención de aceites de oliva de calidad requiere unos cuidados especiales en todas y cada una de las sucesivas fases de elaboración de los mismos, es una cadena que comienza en el olivo y termina en el consumo. Condición indispensable para ello es conocer las características organolépticas del aceite (a fin de potenciar sus atributos y eliminar, en la medida de los posible, sus defectos, y la influencia del proceso de elaboración en las mismas. El control y medida de estos caracteres se hará mediante las catas, realizadas por expertos catadores utilizando para ello las fichas de cata del Consejo Oleícola Internacional. El modelo de Rasch, que emplearemos para obtener la evaluación sensorial de los aceites de oliva virgen, nos permitirá no sólo dar una calificación organoléptica global al aceite (que ya podemos realizar sin necesidad de aplicar ningún método, siguiendo la metodología de valoración del Consejo Oleícola Internacional, sino también clasificar y medir los factores sensoriales que intervienen en la calidad, lo que nos permitirá realizar las acciones oportunas encaminadas a obtener aceites de oliva de cualidades óptimas.

  20. Exploring Variability Sources in Student Evaluation of Teaching via Many-Facet Rasch Model

    Directory of Open Access Journals (Sweden)

    Bengü BÖRKAN

    2017-03-01

    Full Text Available Evaluating quality of teaching is important in nearly every higher education institute. The most common way of assessing teaching effectiveness takes place through students. Student Evaluation of Teaching (SET is used to gather information about students’ experiences with a course and instructor’s performance at some point of semester. SET can be considered as a type of rater mediated performance assessment where students are the raters and instructors are the examinees. When performance assessment becomes a rater mediated assessment process, extra measures need to be taken into consideration in order to create more reliable and fair assessment practices. The study has two main purposes; (a to examine the extent to which the facets (instructor, student, and rating items contribute to instructors’ score variance and (b to examine the students’ judging behavior in order to detect any potential source of bias in student evaluation of teaching by using the Many-Facet Rasch Model. The data set includes one thousand 235 students’ responses from 254 courses. The results show that a students greatly differ in the severity while rating instructors, b students were fairly consistent in their ratings, c students as a group and individual level are tend to display halo effect in their ratings, d students are clustered at the highest two categories of the scale and e the variation in item measures is fairly low. The findings have practical implications for the SET practices by improving the psychometric quality of measurement.

  1. Creating a brief rating scale for the assessment of learning disabilities using reliability and true score estimates of the scale's items based on the Rasch model.

    Science.gov (United States)

    Sideridis, Georgios; Padeliadu, Susana

    2013-01-01

    The purpose of the present studies was to provide the means to create brief versions of instruments that can aid the diagnosis and classification of students with learning disabilities and comorbid disorders (e.g., attention-deficit/hyperactivity disorder). A sample of 1,108 students with and without a diagnosis of learning disabilities took part in study 1. Using information from modern theory methods (i.e., the Rasch model), a scale was created that included fewer than one third of the original battery items designed to assess reading skills. This best item synthesis was then evaluated for its predictive and criterion validity with a valid external reading battery (study 2). Using a sample of 232 students with and without learning disabilities, results indicated that the brief version of the scale was equally effective as the original scale in predicting reading achievement. Analysis of the content of the brief scale indicated that the best item synthesis involved items from cognition, motivation, strategy use, and advanced reading skills. It is suggested that multiple psychometric criteria be employed in evaluating the psychometric adequacy of scales used for the assessment and identification of learning disabilities and comorbid disorders.

  2. Orphan Toxin OrtT (YdcX) of Escherichia coli Reduces Growth during the Stringent Response

    Science.gov (United States)

    2015-01-29

    consists of two-components with the exception of the three-component system ω-ε-ζ of Streptococcus pyogenes [37]. Here, we demonstrate the importance of a...often found in cryptic prophage remnants such as PhyL in Bacillus anthracis [35] and LysA in Streptococcus gordonii [36] without the antitoxin genes...36. Ploeg, J.R.v.d. Characterization of Streptococcus gordonii prophage PH15: Complete genome sequence and functional analysis of phage-encoded

  3. Measuring everyday functional competence using the Rasch assessment of everyday activity limitations (REAL) item bank.

    Science.gov (United States)

    Oude Voshaar, Martijn A H; Ten Klooster, Peter M; Vonkeman, Harald E; van de Laar, Mart A F J

    2017-11-01

    Traditional patient-reported physical function instruments often poorly differentiate patients with mild-to-moderate disability. We describe the development and psychometric evaluation of a generic item bank for measuring everyday activity limitations in outpatient populations. Seventy-two items generated from patient interviews and mapped to the International Classification of Functioning, Disability and Health (ICF) domestic life chapter were administered to 1128 adults representative of the Dutch population. The partial credit model was fitted to the item responses and evaluated with respect to its assumptions, model fit, and differential item functioning (DIF). Measurement performance of a computerized adaptive testing (CAT) algorithm was compared with the SF-36 physical functioning scale (PF-10). A final bank of 41 items was developed. All items demonstrated acceptable fit to the partial credit model and measurement invariance across age, sex, and educational level. Five- and ten-item CAT simulations were shown to have high measurement precision, which exceeded that of SF-36 physical functioning scale across the physical function continuum. Floor effects were absent for a 10-item empirical CAT simulation, and ceiling effects were low (13.5%) compared with SF-36 physical functioning (38.1%). CAT also discriminated better than SF-36 physical functioning between age groups, number of chronic conditions, and respondents with or without rheumatic conditions. The Rasch assessment of everyday activity limitations (REAL) item bank will hopefully prove a useful instrument for assessing everyday activity limitations. T-scores obtained using derived measures can be used to benchmark physical function outcomes against the general Dutch adult population.

  4. Rasch Validation of a Measure of Reform-Oriented Science Teaching Practices

    Science.gov (United States)

    You, Hye Sun

    2016-06-01

    Growing evidence from recent curriculum documents and previous research suggests that reform-oriented science teaching practices promote students' conceptual understanding, levels of achievement, and motivation to learn, especially when students are actively engaged in constructing their ideas through scientific inquiries. However, it is difficult to identify to what extent science teachers engage students in reform-oriented teaching practices (RTPs) in their science classrooms. In order to exactly diagnose the current status of science teachers' implementation of the RTPs, a valid and reliable instrument tool is needed. The principles of validity and reliability are fundamental cornerstones in developing a robust measurement tool. As such, this study was motivated by the desire to point out the limitations of the existing statistical and psychometric analyses and to further examine the validation of the RTP survey instrument. This paper thus aims at calibrating the items of the RTPs for science teachers using the Rasch model. The survey instrument scale was adapted from the 2012 National Survey of Science and Mathematics Education (NSSME) data. A total of 3701 science teachers from 1403 schools from across the USA participated in the NSSME survey. After calibrating the RTP items and persons on the same scale, the RTP instrument well represented the population of US science teachers. Model-data fit determined by Infit and Outfit statistics was within an appropriate range (0.5-1.5), supporting the unidimensional structure of the RTPs. The ordered category thresholds and the probability of the thresholds showed that the five-point rating scale functioned well. The results of this study support the use of the RTP measure from the 2012 NSSME in assessing usage of RTPs.

  5. A developmental screening tool for toddlers with multiple domains based on Rasch analysis

    Directory of Open Access Journals (Sweden)

    Ai-Wen Hwang

    2015-01-01

    Conclusion: MuSiC can be applied simultaneously to well-child care visits as a universal screening tool for children aged 1–3 years on multiple domains. Items with sound validity for infants need to be further developed.

  6. Rasch analysis in the development of a rating scale for assessment of mobility after stroke

    DEFF Research Database (Denmark)

    Engberg, A; Garde, B; Kreiner, S

    1995-01-01

    The study describes the development of a rating scale for assessment of mobility after stroke. It was based on 74 first-stroke patients, 40 men and 34 women, each assessed three times during rehabilitation. Their median age was 69 years, and they represented all degrees of severity of paresis....... Content, construct, criterion and convergent validity were examined, as well as the inter-rater reliability. The final rating scale has three special characteristics: 1) it reflects the regularity in the recovery of mobility after stroke; 2) the sum of item scores comprises the information contained...

  7. Organizational Culture Influence On Total Productive Maintenance (TPM) and Operational Performance Using RASCH Model Analysis

    OpenAIRE

    Mohd Norhasni Mohd Asaad; Rushami Zien Yusoff

    2014-01-01

    Abstract. Market globalization, competitive product and services, high economic crises are the most critical factors that influence the success of the manufacturing companies in global market. Therefore it is critical to the manufacturing companies to be efficient in production and lean tool may used to achieve that.  The most frequently used is the Total Preventive Maintenance (TPM), even though there are many studies have been conducted in relation to the TPM but there is limited research i...

  8. Bayesian Power Prior Analysis and Its Application to Operational Risk and Rasch Model

    Science.gov (United States)

    Zhang, Honglian

    2010-01-01

    When sample size is small, informative priors can be valuable in increasing the precision of estimates. Pooling historical data and current data with equal weights under the assumption that both of them are from the same population may be misleading when heterogeneity exists between historical data and current data. This is particularly true when…

  9. Developing the Communicative Participation Item Bank: Rasch Analysis Results from a Spasmodic Dysphonia Sample

    Science.gov (United States)

    Baylor, Carolyn R.; Yorkston, Kathryn M.; Eadie, Tanya L.; Miller, Robert M.; Amtmann, Dagmar

    2009-01-01

    Purpose: The purpose of this study was to conduct the initial psychometric analyses of the Communicative Participation Item Bank--a new self-report instrument designed to measure the extent to which communication disorders interfere with communicative participation. This item bank is intended for community-dwelling adults across a range of…

  10. Improvement of the Van Lieshout hand function test for tetraplegia using a Rasch analysis.

    NARCIS (Netherlands)

    Spooren, A.I.; Arnould, C.; Smeets, R.J.P.; Bongers, H.M.; Seelen, H.A.M.

    2013-01-01

    STUDY DESIGN: Cross-sectional study. OBJECTIVE: The Van Lieshout hand function test for tetraplegia (VLT) measures the quality of arm-hand functioning in persons with tetraplegia. It is valid, reliable and responsive. However, it does not satisfy all the criteria for interval level measurement. The

  11. <論文>A Rasch Analysis of the Extraversion/Introversion Dimension of Personality

    OpenAIRE

    Paul, Leeming

    2014-01-01

    [Abstract] Researchers interested in individual differences have long sought to categorize personality and to develop a succinct model in order to achieve consistency within different academic fields. As a result of this, the Big Five-Model of Personality has emerged as the dominant model, describing personality in terms of five different traits. Various questionnaires have been developed to measure these traits and the International Personality Item Pool(IPIP)is a well-established and relati...

  12. Identifying Professional Teaching Standards Using Rasch Model Analysis: The Case of Northern Cyprus

    Science.gov (United States)

    Alibaba Erden, Hale; Özer, Bekir

    2013-01-01

    Problem Statement: The Teacher's-Act defined for the state-school teachers of North Cyprus shows that teachers are not selected according to any specific standards. In North Cyprus, apart from the exam topics defined at the teacher's exam regulations, there is not any kind of identified standard for teachers. Training qualified teachers based upon…

  13. A psychometric evaluation of the Swedish version of the Research Utilization Questionnaire using a Rasch measurement model.

    Science.gov (United States)

    Lundberg, Veronica; Boström, Anne-Marie; Malinowsky, Camilla

    2017-07-30

    Evidence-based practice and research utilisation has become a commonly used concept in health care. The Research Utilization Questionnaire (RUQ) has been recognised to be a widely used instrument measuring the perception of research utilisation among nursing staff in clinical practice. Few studies have however analysed the psychometric properties of the RUQ. The aim of this study was to examine the psychometric properties of the Swedish version of the three subscales in RUQ using a Rasch measurement model. This study has a cross-sectional design using a sample of 163 staff (response rate 81%) working in one nursing home in Sweden. Data were collected using the Swedish version of RUQ in 2012. The three subscales Attitudes towards research, Availability of and support for research use and Use of research findings in clinical practice were investigated. Data were analysed using a Rasch measurement model. The results indicate presence of multidimensionality in all subscales. Moreover, internal scale validity and person response validity also provide some less satisfactory results, especially for the subscale Use of research findings. Overall, there seems to be a problem with the negatively worded statements. The findings suggest that clarification and refining of items, including additional psychometric evaluation of the RUQ, are needed before using the instrument in clinical practice and research studies among staff in nursing homes. © 2017 Nordic College of Caring Science.

  14. Historic and future trends of vehicle emissions in Beijing, 1998-2020: A policy assessment for the most stringent vehicle emission control program in China

    Science.gov (United States)

    Zhang, Shaojun; Wu, Ye; Wu, Xiaomeng; Li, Mengliang; Ge, Yunshan; Liang, Bin; Xu, Yueyun; Zhou, Yu; Liu, Huan; Fu, Lixin; Hao, Jiming

    2014-06-01

    As a pioneer in controlling vehicle emissions within China, Beijing released the Clean Air Action Plan 2013-2017 document in August 2013 to improve its urban air quality. It has put forward this plan containing the most stringent emission control policies and strategies to be adopted for on-road vehicles of Beijing. This paper estimates the historic and future trends and uncertainties in vehicle emissions of Beijing from 1998 to 2020 by applying a new emission factor model for the Beijing vehicle fleet (EMBEV). Our updated results show that total emissions of CO, THC, NOx and PM2.5 from the Beijing vehicle fleet are 507 (395-819) kt, 59.1 (41.2-90.5) kt, 74.7 (54.9-103.9) kt and 2.69 (1.91-4.17) kt, respectively, at a 95% confidence level. This represents significant reductions of 58%, 59%, 31% and 62%, respectively, relative to the total vehicle emissions in 1998. The past trends clearly posed a challenge to NOx emission mitigation for the Beijing vehicle fleet, especially in light of those increasing NOx emissions from heavy-duty diesel vehicles (HDDVs) which have partly offset the reduction benefit from light-duty gasoline vehicles (LDGVs). Because of recently announced vehicle emission controls to be adopted in Beijing, including tighter emissions standards, limitations on vehicle growth by more stringent license control, promotion of alternative fuel technologies (e.g., natural gas) and the scrappage of older vehicles, estimated vehicle emissions in Beijing will continue to be mitigated by 74% of CO, 68% of THC, 56% of NOx and 72% of PM2.5 in 2020 compared to 2010 levels. Considering that many of the megacities in China are facing tremendous pressures to mitigate emissions from on-road vehicles, our assessment will provide a timely case study of significance for policy-makers in China.

  15. Using the Many-Facet Rasch Model to Evaluate Standard-Setting Judgments: Setting Performance Standards for Advanced Placement® Examinations

    Science.gov (United States)

    Kaliski, Pamela; Wind, Stefanie A.; Engelhard, George, Jr.; Morgan, Deanna; Plake, Barbara; Reshetar, Rosemary

    2012-01-01

    The Many-Facet Rasch (MFR) Model is traditionally used to evaluate the quality of ratings on constructed response assessments; however, it can also be used to evaluate the quality of judgments from panel-based standard setting procedures. The current study illustrates the use of the MFR Model by examining the quality of ratings obtained from a…

  16. Using the Many-Faceted Rasch Model to Evaluate Standard Setting Judgments: An Illustration with the Advanced Placement Environmental Science Exam

    Science.gov (United States)

    Kaliski, Pamela K.; Wind, Stefanie A.; Engelhard, George, Jr.; Morgan, Deanna L.; Plake, Barbara S.; Reshetar, Rosemary A.

    2013-01-01

    The many-faceted Rasch (MFR) model has been used to evaluate the quality of ratings on constructed response assessments; however, it can also be used to evaluate the quality of judgments from panel-based standard setting procedures. The current study illustrates the use of the MFR model for examining the quality of ratings obtained from a standard…

  17. Rasch Validation and Cross-validation of the Health of Nation Outcome Scales (HoNOS) for Monitoring of Psychiatric Disability in Traumatized Refugees in Western Psychiatric Care

    DEFF Research Database (Denmark)

    Palic, Sabina; Kappel, Michelle Lind; Makransky, Guido

    2016-01-01

    group. A revised 10-item HoNOS fit the Rasch model at pre-treatment, and also showed excellent fit within the cross-validation data. Culture, gender, and need for translation did not exert serious bias on the measure’s performance. The results establish good monitoring properties of the 10-item Ho...

  18. Using Distractor-Driven Standards-Based Multiple-Choice Assessments and Rasch Modeling to Investigate Hierarchies of Chemistry Misconceptions and Detect Structural Problems with Individual Items

    Science.gov (United States)

    Herrmann-Abell, Cari F.; DeBoer, George E.

    2011-01-01

    Distractor-driven multiple-choice assessment items and Rasch modeling were used as diagnostic tools to investigate students' understanding of middle school chemistry ideas. Ninety-one items were developed according to a procedure that ensured content alignment to the targeted standards and construct validity. The items were administered to 13360…

  19. Rasch Modeling of the Test of Early Mathematics Ability-Third Edition with a Sample of K1 Children in Singapore

    Science.gov (United States)

    Yao, Shih-Ying; Muñez, David; Bull, Rebecca; Lee, Kerry; Khng, Kiat Hui; Poon, Kenneth

    2017-01-01

    The Test of Early Mathematics Ability-Third Edition (TEMA-3) is a commonly used measure of early mathematics knowledge for children aged 3 years to 8 years 11 months. In spite of its wide use, research on the psychometric properties of TEMA-3 remains limited. This study applied the Rasch model to investigate the psychometric properties of TEMA-3…

  20. Validación de la escala para manía de la Universidad Nacional de Colombia usando el análisis de Rasch

    Directory of Open Access Journals (Sweden)

    Ricardo Sánchez

    2011-03-01

    Conclusiones. En este primer estudio de la escala para manías usando el análisis de Rasch, se detectó mal ajuste y redundancia de algunos ítems. El síndrome maníaco no queda completamente evaluado por la escala. El instrumento podría mejorarse agregando síntomas depresivos.

  1. Exploring differential item functioning (DIF) with the Rasch model: A comparison of gender differences on eighth-grade science items in the United States and Spain

    Science.gov (United States)

    Calvert, Tasha

    Despite the attention that has been given to gender and science, boys continue to outperform girls in science achievement, particularly by the end of secondary school. Because it is unclear whether gender differences have narrowed over time (Leder, 1992; Willingham & Cole, 1997), it is important to continue a line of inquiry into the nature of gender differences, specifically at the international level. The purpose of this study was to investigate gender differences in science achievement across two countries: United States and Spain. A secondary purpose was to demonstrate an alternative method for exploring gender differences based on the many-faceted Rasch model (1980). A secondary analysis of the data from the Third International Mathematics and Science Study (TIMSS) was used to examine the relationship between gender DIF (differential item functioning) and item characteristics (item type, content, and performance expectation) across both countries. Nationally representative samples of eighth grade students in the United States and Spain who participated in TIMSS were analyzed to answer the research questions in this study. In both countries, girls showed an advantage over boys on life science items and most extended response items, whereas boys, by and large, had an advantage on earth science, physics, and chemistry items. However, even within areas that favored boys, such as physics, there were items that were differentially easier for girls. In general, patterns in gender differences were similar across both countries although there were a few differences between the countries on individual items. It was concluded that simply looking at mean differences does not provide an adequate understanding of the nature of gender differences in science achievement.

  2. Toward improving food safety in the domestic environment: a multi-item Rasch scale for the measurement of the safety efficacy of domestic food-handling practices.

    Science.gov (United States)

    Fischer, Arnout R H; Frewer, Lynn J; Nauta, Maarten J

    2006-10-01

    To reduce consumer health risks from foodborne diseases that result from improper domestic food handling, consumers need to know how to safely handle food. To realize improvements in public health, it is necessary to develop interventions that match the needs of individual consumers. Successful intervention strategies are therefore contingent on identifying not only the practices that are important for consumer protection, but also barriers that prevent consumers from responding to these interventions. A measure of food safety behavior is needed to assess the effectiveness of different intervention strategies across different groups of consumers. A nationally representative survey was conducted in the Netherlands to determine which practices are likely conducted by which consumers. Participants reported their behaviors with respect to 55 different food-handling practices. The Rasch modeling technique was used to determine a general measure for the likelihood of an average consumer performing each food-handling behavior. Simultaneously, an average performance measure was estimated for each consumer. These two measures can be combined to predict the likelihood that an individual consumer engages in a specific food-handling behavior. A single "food safety" dimension was shown to underlie all items. Some potentially safe practices (e.g., use of meat thermometers) were reported as very difficult, while other safe practices were conducted by respondents more frequently (e.g., washing of fresh fruit and vegetables). A cluster analysis was applied to the resulting data set, and five segments of consumers were identified. Different behaviors may have different effects on microbial growth in food, and thus have different consequences for human health. Once the microbial relevance of the different consumer behaviors has been confirmed by experiments and modeling, the scale developed in the research reported here can be used to develop risk communication targeted to the needs

  3. Developing a Measure of Therapist Adherence to Contingency Management: An Application of the Many-Facet Rasch Model.

    Science.gov (United States)

    Chapman, Jason E; Sheidow, Ashli J; Henggeler, Scott W; Halliday-Boykins, Colleen; Cunningham, Phillippe B

    2008-06-01

    A unique application of the Many-Facet Rasch Model (MFRM) is introduced as the preferred method for evaluating the psychometric properties of a measure of therapist adherence to Contingency Management (CM) treatment of adolescent substance use. The utility of psychometric methods based in Classical Test Theory was limited by complexities of the data, including: (a) ratings provided by multiple informants (i.e., youth, caregivers, and therapists), (b) data from separate research studies, (c) repeated measurements, (d) multiple versions of the questionnaire, and (e) missing data. Two dimensions of CM adherence were supported: adherence to Cognitive Behavioral components and adherence to Monitoring components. The rating scale performed differently for items in these subscales, and of 11 items evaluated, eight were found to perform well. The MFRM is presented as a highly flexible approach that can be used to overcome the limitations of traditional methods in the development of adherence measures for evidence-based practices.

  4. Comparing the High School English Curriculum in Turkey through Multi-Analysis

    Science.gov (United States)

    Batdi, Veli

    2017-01-01

    This study aimed to compare the High School English Curriculum (HSEC) in accordance with Stufflebeam's context, input, process and product (CIPP) model through multi-analysis. The research includes both quantitative and qualitative aspects. A descriptive analysis was operated through Rasch Measurement Model; SPSS program for the quantitative…

  5. WARM JUPITERS NEED CLOSE ''FRIENDS'' FOR HIGH-ECCENTRICITY MIGRATION—A STRINGENT UPPER LIMIT ON THE PERTURBER'S SEPARATION

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Subo [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Road 5, Hai Dian District, Beijing 100871 (China); Katz, Boaz; Socrates, Aristotle [Institute for Advanced Study, 1 Einstein Dr., Princeton, NJ 08540 (United States)

    2014-01-20

    We propose a stringent observational test on the formation of warm Jupiters (gas-giant planets with 10 days ≲ P ≲ 100 days) by high-eccentricity (high-e) migration mechanisms. Unlike hot Jupiters, the majority of observed warm Jupiters have pericenter distances too large to allow efficient tidal dissipation to induce migration. To access the close pericenter required for migration during a Kozai-Lidov cycle, they must be accompanied by a strong enough perturber to overcome the precession caused by general relativity, placing a strong upper limit on the perturber's separation. For a warm Jupiter at a ∼ 0.2 AU, a Jupiter-mass (solar-mass) perturber is required to be ≲ 3 AU (≲ 30 AU) and can be identified observationally. Among warm Jupiters detected by radial velocities (RVs), ≳ 50% (5 out of 9) with large eccentricities (e ≳ 0.4) have known Jovian companions satisfying this necessary condition for high-e migration. In contrast, ≲ 20% (3 out of 17) of the low-e (e ≲ 0.2) warm Jupiters have detected additional Jovian companions, suggesting that high-e migration with planetary perturbers may not be the dominant formation channel. Complete, long-term RV follow-ups of the warm-Jupiter population will allow a firm upper limit to be put on the fraction of these planets formed by high-e migration. Transiting warm Jupiters showing spin-orbit misalignments will be interesting to apply our test. If the misalignments are solely due to high-e migration as commonly suggested, we expect that the majority of warm Jupiters with low-e (e ≲ 0.2) are not misaligned, in contrast with low-e hot Jupiters.

  6. Inducible Expression of Agrobacterium Virulence Gene VirE2 for Stringent Regulation of T-DNA Transfer in Plant Transient Expression Systems.

    Science.gov (United States)

    Denkovskienė, Erna; Paškevičius, Šarūnas; Werner, Stefan; Gleba, Yuri; Ražanskienė, Aušra

    2015-11-01

    Agrotransfection with viral vectors is an effective solution for the transient production of valuable proteins in plants grown in contained facilities. Transfection methods suitable for field applications are desirable for the production of high-volume products and for the transient molecular reprogramming of plants. The use of genetically modified (GM) Agrobacterium strains for plant transfections faces substantial biosafety issues. The environmental biosafety of GM Agrobacterium strains could be improved by regulating their T-DNA transfer via chemically inducible expression of virE2, one of the essential Agrobacterium virulence genes. In order to identify strong and stringently regulated promoters in Agrobacterium strains, we evaluated isopropyl-β-d-thiogalactoside-inducible promoters Plac, Ptac, PT7/lacO, and PT5/lacOlacO and cumic acid-inducible promoters PlacUV5/CuO, Ptac/CuO, PT5/CuO, and PvirE/CuO. Nicotiana benthamiana plants were transfected with a virE2-deficient A. tumefaciens strain containing transient expression vectors harboring inducible virE2 expression cassettes and containing a marker green fluorescent protein (GFP) gene in their T-DNA region. Evaluation of T-DNA transfer was achieved by counting GFP expression foci on plant leaves. The virE2 expression from cumic acid-induced promoters resulted in 47 to 72% of wild-type T-DNA transfer. Here, we present efficient and tightly regulated promoters for gene expression in A. tumefaciens and a novel approach to address environmental biosafety concerns in agrobiotechnology.

  7. With hiccups and bumps: the development of a Rasch-based instrument to measure elementary students' understanding of the nature of science.

    Science.gov (United States)

    Peoples, Shelagh M; O'Dwyer, Laura M; Shields, Katherine A; Wang, Yang

    2013-01-01

    This research describes the development process, psychometric analyses and part validation study of a theoretically-grounded Rasch-based instrument, the Nature of Science Instrument-Elementary (NOSI-E). The NOSI-E was designed to measure elementary students' understanding of the Nature of Science (NOS). Evidence is provided for three of the six validity aspects (content, substantive and generalizability) needed to support the construct validity of the NOSI-E. A future article will examine the structural and external validity aspects. Rasch modeling proved especially productive in scale improvement efforts. The instrument, designed for large-scale assessment use, is conceptualized using five construct domains. Data from 741 elementary students were used to pilot the Rasch scale, with continuous improvements made over three successive administrations. The psychometric properties of the NOSI-E instrument are consistent with the basic assumptions of Rasch measurement, namely that the items are well-fitting and invariant. Items from each of the five domains (Empirical, Theory-Laden, Certainty, Inventive, and Socially and Culturally Embedded) are spread along the scale's continuum and appear to overlap well. Most importantly, the scale seems appropriately calibrated and responsive for elementary school-aged children, the target age group. As a result, the NOSI-E should prove beneficial for science education research. As the United States' science education reform efforts move toward students' learning science through engaging in authentic scientific practices (NRC, 2011), it will be important to assess whether this new approach to teaching science is effective. The NOSI-E can be used as one measure of whether this reform effort has an impact.

  8. Propriedades psicométricas da versão brasileira da escala de qualidade de vida específica para acidente vascular encefálico: aplicação do modelo Rasch Psychometric properties of the Brazilian version of the Stroke Specific Quality of Life Scale: application of the Rasch model

    Directory of Open Access Journals (Sweden)

    RCM Lima

    2008-04-01

    Full Text Available CONTEXTUALIZAÇÃO: O acidente vascular encefálico (AVE produz déficits importantes na qualidade de vida (QV dos indivíduos. Medidas específicas de QV são necessárias para compreender e quantificar o impacto dessa patologia. OBJETIVO: O objetivo desse estudo foi adaptar transculturalmente o Stroke Specific Quality of Life Scale (SSQOL para o Português (Brasil e avaliar suas propriedades psicométricas. MATERIAIS E MÉTODOS: O SSQOL foi traduzido e adaptado seguindo instruções padronizadas e submetido a exame de confiabilidade teste-reteste (10 hemiplégicos. As propriedades psicométricas foram investigadas pela análise Rasch em 50 hemiplégicos. RESULTADOS: Foram detectados coeficientes de confiabilidade de 0,92 para itens e indivíduos. O índice de separação dos hemiplégicos foi 3,34 e dos itens, 3,36, ou seja, os itens separaram as pessoas em pelo menos três níveis de QV e em três níveis de QV - baixa, média e alta. Dos 49 itens, quatro não se enquadram no modelo, o que compromete a validade de constructo do instrumento, embora o padrão errático dos itens se justifique na amostra examinada. CONCLUSÕES: O instrumento mostrou-se clinicamente útil na população avaliada. Novos estudos em populações com outras características já estão em andamento.BACKGROUND: Stroke results in important deficits, which reduce individuals’ quality of life (QOL. Specific QOL measurements are necessary to understand and quantify the impact of this pathological condition. OBJECTIVE: The aim of this study was to make a transcultural adaptation of the Stroke Specific Quality of Life Scale (SSQOL into Brazilian Portuguese and to assess its psychometric properties. METHODS: The SSQOL was translated and adapted in accordance with standardized procedures and was subjected to test-retest reliability analysis with 10 hemiplegic subjects. The psychometric properties were investigated using Rasch analysis on 50 hemiplegics. RESULTS: Reliability

  9. A rasch model to test the cross-cultural validity in the positive and negative syndrome scale (PANSS) across six geo-cultural groups.

    Science.gov (United States)

    Khan, Anzalee; Yavorsky, Christian; Liechti, Stacy; Opler, Mark; Rothman, Brian; DiClemente, Guillermo; Lucic, Luka; Jovic, Sofija; Inada, Toshiya; Yang, Lawrence

    2013-01-01

    The objective of this study was to examine the cross-cultural differences of the PANSS across six geo-cultural regions. The specific aims are (1) to examine measurement properties of the PANSS; and (2) to examine how each of the 30 items function across geo-cultural regions. Data was obtained for 1,169 raters from 6 different regions: Eastern Asia (n = 202), India (n = 185), Northern Europe (n = 126), Russia & Ukraine (n = 197), Southern Europe (n = 162), United States (n = 297). A principle components analysis assessed unidimensionality of the subscales. Rasch rating scale analysis examined cross-cultural differences among each item of the PANSS. Lower item values reflects items in which raters often showed less variation in the scores; higher item values reflects items with more variation in the scores. Positive Subscale: Most regions found item P5 (Excitement) to be the most difficult item to score. Items varied in severity from -0.93 [item P6. Suspiciousness/persecution (USA) to 0.69 item P4. Excitement (Eastern Asia)]. Item P3 (Hallucinatory Behavior) was the easiest item to score for all geographical regions. Negative Subscale: The most difficult item to score for all regions is N7 (Stereotyped Thinking) with India showing the most difficulty Δ = 0.69, and Northern Europe and the United States showing the least difficulty Δ = 0.21, each. The second most difficult item for raters to score was N1 (Blunted Affect) for most countries including Southern Europe (Δ = 0.30), Eastern Asia (Δ = 0.28), Russia & Ukraine (Δ = 0.22) and India (Δ = 0.10). General Psychopathology: The most difficult item for raters to score for all regions is G4 (Tension) with difficulty levels ranging from Δ = 1.38 (India) to Δ = 0.72. There were significant differences in response to a number of items on the PANSS, possibly caused by a lack of equivalence between the original and translated versions, cultural differences among interpretation of items or scoring parameters. Knowing

  10. Rasch modelling to deal with changes in the questionnaires used during long-term follow-up of cohort studies: a simulation study.

    Science.gov (United States)

    Rouquette, Alexandra; Côté, Sylvana M; Hardouin, Jean-Benoit; Falissard, Bruno

    2016-08-24

    A specific measurement issue often occurs in cohort studies with long-term follow-up: the substitution of the classic instruments used to assess one or several factors or outcomes studied by new, more reliable, more accurate or more convenient instruments. This study aimed to compare three techniques to deal with this issue when the substituted instrument is a questionnaire measuring a subjective phenomenon: one using only the items shared by the different questionnaires over time, i.e. computation of the raw score; the two others using every item, i.e. computation of the standardised score or estimation of the latent variable score using the Rasch model. Two hundred databases were simulated, corresponding to longitudinal 10-item questionnaire data from three trajectory groups of subjects for the subjective phenomenon of interest ("increasing", "stable-low" or "stable-high" mean trajectory over time). Three copies of these databases were generated and the subjects' responses to some items were removed at some collection times leading to a number of shared items over time varying from 4 to 10 in the 800 datasets. The performances of Latent Class Growth Analysis (LCGA) applied to the raw score, the standardised score or the latent variable score were studied on these databases according to the number of shared items over time. Surprisingly, LCGA applied to the latent variable score estimate did not perform as well as LCGA applied to the standardised score, where it was the most efficient whatever the number of shared items. However, the proportions of correctly classified subjects by LCGA applied to the latent variable score were more balanced across trajectory groups. The use of the standardised score to deal with questionnaire changes over time was more efficient than the raw score and also, surprisingly, than the latent variable score. LCGA applied to the raw score was the least efficient and exhibited the most unbalanced misclassifications across trajectory

  11. Rasch modelling to deal with changes in the questionnaires used during long-term follow-up of cohort studies: a simulation study

    Directory of Open Access Journals (Sweden)

    Alexandra Rouquette

    2016-08-01

    Full Text Available Abstract Background A specific measurement issue often occurs in cohort studies with long-term follow-up: the substitution of the classic instruments used to assess one or several factors or outcomes studied by new, more reliable, more accurate or more convenient instruments. This study aimed to compare three techniques to deal with this issue when the substituted instrument is a questionnaire measuring a subjective phenomenon: one using only the items shared by the different questionnaires over time, i.e. computation of the raw score; the two others using every item, i.e. computation of the standardised score or estimation of the latent variable score using the Rasch model. Methods Two hundred databases were simulated, corresponding to longitudinal 10-item questionnaire data from three trajectory groups of subjects for the subjective phenomenon of interest (“increasing”, “stable-low” or “stable-high” mean trajectory over time. Three copies of these databases were generated and the subjects’ responses to some items were removed at some collection times leading to a number of shared items over time varying from 4 to 10 in the 800 datasets. The performances of Latent Class Growth Analysis (LCGA applied to the raw score, the standardised score or the latent variable score were studied on these databases according to the number of shared items over time. Results Surprisingly, LCGA applied to the latent variable score estimate did not perform as well as LCGA applied to the standardised score, where it was the most efficient whatever the number of shared items. However, the proportions of correctly classified subjects by LCGA applied to the latent variable score were more balanced across trajectory groups. Conclusions The use of the standardised score to deal with questionnaire changes over time was more efficient than the raw score and also, surprisingly, than the latent variable score. LCGA applied to the raw score was the least

  12. Latent Transition Analysis with a Mixture Item Response Theory Measurement Model

    Science.gov (United States)

    Cho, Sun-Joo; Cohen, Allan S.; Kim, Seock-Ho; Bottge, Brian

    2010-01-01

    A latent transition analysis (LTA) model was described with a mixture Rasch model (MRM) as the measurement model. Unlike the LTA, which was developed with a latent class measurement model, the LTA-MRM permits within-class variability on the latent variable, making it more useful for measuring treatment effects within latent classes. A simulation…

  13. Anchor Selection Strategies for DIF Analysis: Review, Assessment, and New Approaches

    Science.gov (United States)

    Kopf, Julia; Zeileis, Achim; Strobl, Carolin

    2015-01-01

    Differential item functioning (DIF) indicates the violation of the invariance assumption, for instance, in models based on item response theory (IRT). For item-wise DIF analysis using IRT, a common metric for the item parameters of the groups that are to be compared (e.g., for the reference and the focal group) is necessary. In the Rasch model,…

  14. Assessment of Student Performance for Course Examination Using Rasch Measurement Model: A Case Study of Information Technology Fundamentals Course

    Directory of Open Access Journals (Sweden)

    Amir Mohamed Talib

    2018-01-01

    Full Text Available This paper describes a measurement model that is used to measure the student performance in the final examination of Information Technology (IT Fundamentals (IT280 course in the Information Technology (IT Department, College of Computer & Information Sciences (CCIS, Al-Imam Mohammad Ibn Saud Islamic University (IMSIU. The assessment model is developed based on students’ mark entries of final exam results for the second year IT students, which are compiled and tabulated for evaluation using Rasch Measurement Model, and it can be used to measure the students’ performance towards the final examination of the course. A study on 150 second year students (male = 52; female = 98 was conducted to measure students’ knowledge and understanding for IT280 course according to the three level of Bloom’s Taxonomy. The results concluded that students can be categorized as poor (10%, moderate (42%, good (18%, and successful (24% to achieve Level 3 of Bloom’s Taxonomy. This study shows that the students’ performance for the set of IT280 final exam questions was comparatively good. The result generated from this study can be used to guide us to determine the appropriate improvement of teaching method and the quality of question prepared.

  15. Reducing the item number to obtain the same-length self-assessment scales: a systematic approach using result of graphical loglinear rasch models

    DEFF Research Database (Denmark)

    Nielsen, Tine; Kreiner, Svend

    2011-01-01

    . For self-assessment, self-scoring and self-interpretational purposes it is deemed prudent that subscales measuring comparable constructs are of the same item length. Consequently, in order to obtain a self-assessment version of the R-D-LSI with an equal number of items in each subscale, a systematic...... approach to item reduction based on results of graphical loglinear Rasch modeling (GLLRM) was designed. This approach was then used to reduce the number of items in the subscales of the R-D-LSI which had an item-length of more than seven items, thereby obtaining the Danish Self-Assessment Learning Styles...

  16. The relationship between the Rating Scale and Partial Credit Models and the implication of disordered thresholds of the Rasch models for polytomous responses.

    Science.gov (United States)

    Luo, Guanzhong

    2005-01-01

    There is a perception in the literature that the Rating Scale Model (RSM) and Partial Credit Model (PCM) are two different types of Rasch models. This paper clarifies the relationship between the RSM and PCM from the perspectives of literature history and mathematical logic. It is shown that not only are the RSM and the PCM identical, but the two approaches used to introduce them are statistically equivalent. Then the implication of disordered thresholds is discussed. In addition, the difference between the structural thresholds and the Thurstone thresholds are clarified.

  17. Quality of life in the Danish general population--normative data and validity of WHOQOL-BREF using Rasch and item response theory models

    DEFF Research Database (Denmark)

    Noerholm, V; Groenvold, M; Watt, T

    2004-01-01

    BACKGROUND: The main objective of this study was to investigate the construct validity of the WHOQOL-BREF by use of Rasch and Item Response Theory models and to examine the stability of the model across high/low scoring individuals, gender, education, and depressive illness. Furthermore......, the objective of the study was to estimate the reference data for the quality of life questionnaire WHOQOL-BREF in the general Danish population and in subgroups defined by age, gender, and education. METHODS: Mail-out-mail-back questionnaires were sent to a randomly selected sample of the Danish general...

  18. Rasch modeling of the Spanish self-report version of the Liebowitz Social Anxiety Scale for Children and Adolescents (LSAS-CA-SR

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    José A. López-Pina

    2008-01-01

    Full Text Available El objetivo de este estudio instrumental fue analizar la estructura unidimensional de las subescalas de miedo y evitación de la versión española de la escala de ansiedad social LSAS-CA-SR para niños y adolescentes bajo la familia de modelos de Rasch. La muestra estuvo formada por 454 estudiantes (236 varones y 218 mujeres de educación primaria y secundaria cuya edad variaba entre 10 y 17 años. El modelo de escalas de valoración fue ajustado a los datos de ambas subescalas. Los estadísticos de ajuste (media cuadrática ponderada y media cuadrática no ponderada mostraron un buen ajuste de los ítems al modelo, excepto en los ítems 10 y 16 en la subescala de miedo, y los ítems 6, 7 y 21 en la subescala de evitación. Además, la subdivisión de la muestra global en dos submuestras aleatorias de 150 personas probó que el modelo de escalas de valoración produjo un ordenamiento invariante de los parámetros de los ítems y de los parámetros de las personas. Este estudio respalda, así, la utilidad del modelo de Rasch y su familia para determinar la unidimensionalidad en un test psicológico.

  19. Validity of personality measurement in adults with anxiety disorders: Psychometric properties of the Spanish NEO-FFI-R using Rasch Analyses

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    Félix eInchausti

    2015-04-01

    Full Text Available The aim of this study was to analyze the psychometric properties of the Spanish NEO-FFI-R using Rasch analyses, in order to test its rating scale functioning, the reliability of scores, internal structure, and Differential Item Functioning (DIF by gender in a psychiatric sample. The NEO-FFI-R responses of 433 Spanish adults (154 males with an anxiety disorder as primary diagnosis were analyzed using the Rasch model for rating scales. Two intermediate categories of response (‘neutral’ and ‘agree’ malfunctioned in the Neuroticism and Conscientiousness scales. In addition, model reliabilities were lower than expected in Agreeableness and Neuroticism, and the item fit values indicated each scale had items that did not achieve moderate to high discrimination on its dimension, particularly in the Agreeableness scale. Concerning unidimensionality, the five NEO-FFI-R scales showed large first components of unexplained variance. Finally, DIF by gender was detected in many items. The results suggest that the scores of the Spanish NEO-FFI-R are unreliable in psychiatric samples and cannot be generalized between males and females, especially in the Openness, Conscientiousness, and Agreeableness scales. Future directions for testing and refinement should be developed before the NEO-FFI-R can be used reliably in clinical samples.

  20. Development of a Microsoft Excel tool for one-parameter Rasch model of continuous items: an application to a safety attitude survey

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    Tsair-Wei Chien

    2017-01-01

    Full Text Available Abstract Background Many continuous item responses (CIRs are encountered in healthcare settings, but no one uses item response theory’s (IRT probabilistic modeling to present graphical presentations for interpreting CIR results. A computer module that is programmed to deal with CIRs is required. To present a computer module, validate it, and verify its usefulness in dealing with CIR data, and then to apply the model to real healthcare data in order to show how the CIR that can be applied to healthcare settings with an example regarding a safety attitude survey. Methods Using Microsoft Excel VBA (Visual Basic for Applications, we designed a computer module that minimizes the residuals and calculates model’s expected scores according to person responses across items. Rasch models based on a Wright map and on KIDMAP were demonstrated to interpret results of the safety attitude survey. Results The author-made CIR module yielded OUTFIT mean square (MNSQ and person measures equivalent to those yielded by professional Rasch Winsteps software. The probabilistic modeling of the CIR module provides messages that are much more valuable to users and show the CIR advantage over classic test theory. Conclusions Because of advances in computer technology, healthcare users who are familiar to MS Excel can easily apply the study CIR module to deal with continuous variables to benefit comparisons of data with a logistic distribution and model fit statistics.

  1. Bilimsel Araştırma Ödevlerinin Çok Yüzeyli Rasch Ölçme Modeli ile Değerlendirilmesi

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    Ramazan BAŞTÜRK

    2010-06-01

    Full Text Available The purpose of this study is to investigate the usefulness of the many-facet Rasch model (MFRM in evaluating the quality of performance related to preparing Research assignment in higher education. The Rasch Model utilizes item response theory stating that the probability of a correct response to a test item/task depends largely on a single parameter, the ability of the person. MFRM extends this one-parameter model to other facets, for example, rater severity, rating scale format, task difficulty levels. This paper specifically investigated research preparation ability in terms of items/task difficulty and rater severity/leniency. Fourth year counseling students prepared research assignments during the autumn semester of the 2009-2010 school years in the “Research Methods in Education” course. Six judges evaluated each students assignments using “Research Assignment Evaluation Rubric”. The results of this study demonstrated that the MFRM is a powerful tool for handling polytomous data in performance and peer assessment in higher education.

  2. Development of a Microsoft Excel tool for one-parameter Rasch model of continuous items: an application to a safety attitude survey.

    Science.gov (United States)

    Chien, Tsair-Wei; Shao, Yang; Kuo, Shu-Chun

    2017-01-10

    Many continuous item responses (CIRs) are encountered in healthcare settings, but no one uses item response theory's (IRT) probabilistic modeling to present graphical presentations for interpreting CIR results. A computer module that is programmed to deal with CIRs is required. To present a computer module, validate it, and verify its usefulness in dealing with CIR data, and then to apply the model to real healthcare data in order to show how the CIR that can be applied to healthcare settings with an example regarding a safety attitude survey. Using Microsoft Excel VBA (Visual Basic for Applications), we designed a computer module that minimizes the residuals and calculates model's expected scores according to person responses across items. Rasch models based on a Wright map and on KIDMAP were demonstrated to interpret results of the safety attitude survey. The author-made CIR module yielded OUTFIT mean square (MNSQ) and person measures equivalent to those yielded by professional Rasch Winsteps software. The probabilistic modeling of the CIR module provides messages that are much more valuable to users and show the CIR advantage over classic test theory. Because of advances in computer technology, healthcare users who are familiar to MS Excel can easily apply the study CIR module to deal with continuous variables to benefit comparisons of data with a logistic distribution and model fit statistics.

  3. New insights into the regulatory pathways associated with the activation of the stringent response in bacterial resistance to the PBP2-targeted antibiotics, mecillinam and OP0595/RG6080.

    Science.gov (United States)

    Doumith, M; Mushtaq, S; Livermore, D M; Woodford, N

    2016-10-01

    The diazabicyclooctane β-lactamase inhibitor OP0595 (RG6080) also acts as an antibiotic, targeting PBP2 in Enterobacteriaceae, but this activity is vulnerable to mutational resistance. We used WGS to investigate the basis of this resistance. Twenty OP0595-selected mutants, comprising four derived from each of five different Escherichia coli strains, were sequenced on Illumina HiSeq. Reads from each mutant were mapped to the assembled genome of the corresponding parent. A variant-calling file generated with Samtools was parsed to determine genetic alterations. Besides OP0595, the mutants consistently showed decreased susceptibility to mecillinam, which likewise targets PBP2, and grew as stable round forms in the presence of subinhibitory concentrations of OP0595. Among the 20 mutants, 18 had alterations in genes encoding tRNA synthase and modification functions liable to induce expression of the RpoS sigma factor through activation of the stringent response or had mutations suppressing inactivators of RpoS or the stringent response signal-degrading enzyme, SpoT. TolB was inactivated in one mutant: this activates RcsBC regulation and was previously associated with mecillinam resistance. The mechanism of resistance remained unidentified in one mutant. Both the RpoS and RcsBC systems regulate genes of cell division, including ftsAQZ that can compensate for loss or inhibition of PBP2, allowing survival of the challenged bacteria as stable round forms, as seen. WGS identified the global stringent response signal, entailing induction of RpoS, as the main mediator of mutational resistance to OP0595 in E. coli. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Structural Modeling of Measurement Error in Generalized Linear Models with Rasch Measures as Covariates

    Science.gov (United States)

    Battauz, Michela; Bellio, Ruggero

    2011-01-01

    This paper proposes a structural analysis for generalized linear models when some explanatory variables are measured with error and the measurement error variance is a function of the true variables. The focus is on latent variables investigated on the basis of questionnaires and estimated using item response theory models. Latent variable…

  5. Development of a Short-Form Measure of Science and Technology Self-efficacy Using Rasch Analysis

    Science.gov (United States)

    Lamb, Richard L.; Vallett, David; Annetta, Leonard

    2014-10-01

    Despite an increased focus on science, technology, engineering, and mathematics (STEM) in U.S. schools, today's students often struggle to maintain adequate performance in these fields compared with students in other countries (Cheek in Thinking constructively about science, technology, and society education. State University of New York, Albany, 1992; Enyedy and Goldberg 2004; Mandinach and Lewis 2006). In addition, despite considerable pressure to promote the placement of students into STEM career fields, U.S. placement is relatively low (Sadler et al. in Sci Educ 96(3):411-427, 2012; Subotnik et al. in Identifying and developing talent in science, technology, engineering, and mathematics (STEM): an agenda for research, policy and practice. International handbook, part XII, pp 1313-1326, 2009). One explanation for the decline of STEM career placement in the U.S. rests with low student affect concerning STEM concepts and related content, especially in terms of self-efficacy. Researchers define self-efficacy as the internal belief that a student can succeed in learning, and that understanding student success lies in students' externalized actions or behaviors (Bandura in Psychol Rev 84(2):191-215, 1977). Evidence suggests that high self-efficacy in STEM can result in student selection of STEM in later educational endeavors, culminating in STEM career selection (Zeldin et al. in J Res Sci Teach 45(9):1036-1058, 2007). However, other factors such as proficiency play a role as well. The lack of appropriate measures of self-efficacy can greatly affect STEM career selection due to inadequate targeting of this affective trait and loss of opportunity for early intervention by educators. Lack of early intervention decreases selection of STEM courses and careers (Valla and Williams in J Women Minor Sci Eng 18(1), 2012; Lent et al. in J Couns Psychol 38(4), 1991). Therefore, this study developed a short-form measure of self-efficacy to help identify students in need of intervention.

  6. Challenges to Measuring Chinese Students' Perceptions of Freedom of Expression: An Application of Rasch Analysis

    Science.gov (United States)

    Qin, Lixia; Torres, Mario

    2018-01-01

    Rapid social development and recent changes in views concerning childhood have urged a more holistic approach to measuring children's well-being, particularly in the domain of rights. In light of articulated provisions within the United Nations Convention on the Rights of the Child, there is obvious interest in understanding more about how…

  7. Low Back Pain in 17 Countries, a Rasch Analysis of the ICF Core Set for Low Back Pain

    Science.gov (United States)

    Roe, Cecilie; Bautz-Holter, Erik; Cieza, Alarcos

    2013-01-01

    Previous studies indicate that a worldwide measurement tool may be developed based on the International Classification of Functioning Disability and Health (ICF) Core Sets for chronic conditions. The aim of the present study was to explore the possibility of constructing a cross-cultural measurement of functioning for patients with low back pain…

  8. Initial Development of the Teen Screen for Dating Violence: Exploratory Factor Analysis, Rasch Model, and Psychometric Data

    Science.gov (United States)

    Emelianchik-Key, Kelly; Hays, Danica G.; Hill, Tara

    2018-01-01

    The Teen Screen for Dating Violence (TSDV) is an assessment that examines adolescent dating violence perpetration and victimization, perception and exposure to violence, and support systems. Through assessment, adolescents who are at high risk could be identified for prevention and early intervention. This article presents the development,…

  9. Seeking Missing Pieces in Science Concept Assessments: Reevaluating the Brief Electricity and Magnetism Assessment through Rasch Analysis

    Science.gov (United States)

    Ding, Lin

    2014-01-01

    Discipline-based science concept assessments are powerful tools to measure learners' disciplinary core ideas. Among many such assessments, the Brief Electricity and Magnetism Assessment (BEMA) has been broadly used to gauge student conceptions of key electricity and magnetism (E&M) topics in college-level introductory physics courses.…

  10. Differential item functional analysis on pedagogic and content knowledge (PCK) questionnaire for Indonesian teachers using RASCH model

    Science.gov (United States)

    Rahmani, B. D.

    2018-01-01

    The purpose of this paper is to evaluate Indonesian senior high school teacher’s pedagogical content knowledge also their perception toward curriculum changing in West Java Indonesia. The data used in this study were derived from a questionnaire survey conducted among teachers in Bandung, West Java. A total of 61 usable responses were collected. The Differential Item Functioning (DIFF) was used to analyze the data whether the item had a difference or not toward gender, education background also on school location. However, the result showed that there was no any significant difference on gender and school location toward the item response but educational background. As a conclusion, the teacher’s educational background influence on giving the response to the questionnaire. Therefore, it is suggested in the future to construct the items on the questionnaire which is coped the differences of the participant particularly the educational background.

  11. The importance of statistical modelling in clinical research : Comparing multidimensional Rasch-, structural equation and linear regression models for analyzing the depression of relatives of psychiatric patients.

    Science.gov (United States)

    Alexandrowicz, Rainer W; Jahn, Rebecca; Friedrich, Fabian; Unger, Anne

    2016-06-01

    Various studies have shown that caregiving relatives of schizophrenic patients are at risk of suffering from depression. These studies differ with respect to the applied statistical methods, which could influence the findings. Therefore, the present study analyzes to which extent different methods may cause differing results. The present study contrasts by means of one data set the results of three different modelling approaches, Rasch Modelling (RM), Structural Equation Modelling (SEM), and Linear Regression Modelling (LRM). The results of the three models varied considerably, reflecting the different assumptions of the respective models. Latent trait models (i. e., RM and SEM) generally provide more convincing results by correcting for measurement error and the RM specifically proves superior for it treats ordered categorical data most adequately.

  12. Gender fairness in self-efficacy? A Rasch-based validity study of the General Academic Self-efficacy scale (GASE)

    DEFF Research Database (Denmark)

    Nielsen, Tine; Vang, Maria Louison; Dammeyer, Jesper

    2018-01-01

    Studies have reported gender differences in academic self-efficacy. However, how and if academic self-efficacy questionnaires are gender-biased has not been psychometrically investigated. The psychometric properties of a general version of The Physics Self-Efficacy Questionnaire – the General...... Academic Self-Efficacy Scale (GASE) – were analyzed using Rasch measurement models, with data from 1018 Danish university students (psychology and technical), focusing on gender invariance and the sufficiency of the score. The short 4-item GASE scale was found to be essentially objective and construct...... valid and satisfactorily reliable, though differential item functioning was found relative to gender and academic discipline, and can be used to assess students’ general academic self-efficacy. Research on gender and self-efficacy needs to take gender into account and equate scores appropriately...

  13. Assessing DIF among small samples with separate calibration t and Mantel-Haenszel χ² statistics in the Rasch model.

    Science.gov (United States)

    Bernstein, Ira; Samuels, Ellery; Woo, Ada; Hagge, Sarah L

    2013-01-01

    The National Council Licensure Examination (NCLEX) program has evaluated differential item functioning (DIF) using the Mantel-Haenszel (M-H) chi-square statistic. Since a Rasch model is assumed, DIF implies a difference in item difficulty between a reference group, e.g., White applicants, and a focal group, e.g., African-American applicants. The National Council of State Boards of Nursing (NCSBN) is planning to change the statistic used to evaluate DIF on the NCLEX from M-H to the separate calibration t-test (t). In actuality, M-H and t should yield identical results in large samples if the assumptions of the Rasch model hold (Linacre and Wright, 1989, also see Smith, 1996). However, as is true throughout statistics, "how large is large" is undefined, so it is quite possible that systematic differences exist in relatively smaller samples. This paper compares M-H and t in four sets of computer simulations. Three simulations used a ten-item test with nine fair items and one potentially containing DIF. To address instability that may result from a ten-item test, the fourth used a 30-item test with 29 fair items and one potentially containing DIF. Depending upon the simulation, the magnitude of population DIF (0, .5, 1.0, and 1.5 z-score units), the ability difference between the focal and reference group (-1, 0, and 1 z-score units), the focal group size (0, 10, 20, 40, 50, 80, 160, and 1000), and the reference group size (500 and 1000) were varied. The results were that: (a) differences in estimated DIF between the M-H and t statistics are generally small, (b) t tends to estimate lower chance probabilities than M-H with small sample sizes, (c) neither method is likely to detect DIF, especially when it is of slight magnitude in small focal group sizes, and (d) M-H does marginally better than t at detecting DIF but this improvement is also limited to very small focal group sizes.

  14. A plea for more general tests than those for location only: Further considerations on Rasch & Guiard’s ‘The robustness of parametric statistical methods’

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    WOLFGANG T. WIEDERMANN

    2007-03-01

    Full Text Available Starting with the discussion between Rasch & Guiard (2004 and von Eye (2004 concerning the use of parametric and nonparametric tests for the comparison of two samples a further approach toward this question is undertaken. Student’s t-test requires for its application interval scaled and normally distributed data along with homogeneous variances across groups. In case that at least one of these prerequisites is not fulfilled, common statistical textbooks for social sciences usually refer to the nonparametric Wilcoxon-Mann-Whitney test. Earlier simulation studies revealed the t-test to be rather robust concerning distributional assumptions. The current study extends these findings with respect to the simultaneous violation of distributional and homogeneity assumptions. A simulation study has shown that both tests lead to highly contradicting results, and a more general approach toward the question of whether parametric or nonparametric procedures should be used, is introduced. Results indicate that the U-Test seems to be in general a more proper instrument for psychological research.

  15. Evaluation of the Psychometric Properties of the Internet Addiction Test (IAT in a Sample of Cypriot High School Students: The Rasch Measurement Perspective

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    Panayiotis Panayides

    2012-08-01

    Full Text Available As Greek Cypriot senior high school teachers, the researchers believe that instruments assessing Internet addiction should be developed and validated for use wherever there are adolescents (the most at-risk population and Internet access. The purpose of the study was to evaluate the psychometric properties of the Internet Addiction Test (IAT. A sample of 604 randomly selected high school students from five high schools in Limassol, Cyprus participated in the study. The Rasch Rating Scale Model was used for the analyses of the data collected. Results suggested the modification of the IAT in two ways. First, the 5-point rating scale was replaced by a 3-point scale, which was found to be optimal in the pilot study. Second, item 8 was replaced by a self-rating item because it was found to be identical to item 6 both statistically and semantically. The respondents’ reliability was satisfactory (0.86 and item reliability very high (0.99. All 20 items were sufficiently spread out and describe distinct levels along the variable and do define a linear continuum of increasing difficulty. All the evidence collected supports the unidimensionality and the high degree of construct validity of the scale. Finally four recommendations for the modification of the scale and future research are proposed.

  16. Use of the Rasch measurement model to explore the relationship between content knowledge and topic-specific pedagogical content knowledge for organic chemistry

    Science.gov (United States)

    Davidowitz, Bette; Potgieter, Marietjie

    2016-06-01

    Research has shown that a high level of content knowledge (CK) is necessary but not sufficient to develop the special knowledge base of expert teachers known as pedagogical content knowledge (PCK). This study contributes towards research to quantify the relationship between CK and PCK in science. In order to determine the proportion of the variance in PCK accounted for by the variance in CK, instruments are required which are valid and reliable as well as being unidimensional to measure person abilities for CK and PCK. An instrument consisting of two paper-and-pencil tests was designed to assess Grade 12 teachers CK and PCK in organic chemistry. We used the Rasch measurement model to convert raw score data into interval measures and to provide empirical evidence for the validity, reliability and unidimensionality of the tests. The correlation between CK and PCK was estimated as r = .66 (p < .001). We found evidence to suggest that while topic-specific PCK (TSPCK) develops with increasing teaching experience, high levels of CK can be acquired with limited teaching experience. These findings support the hypothesis that CK is a requirement for the development of TSPCK; proficiency in CK is, however, not necessarily associated with high levels of TSPCK.

  17. Análise das propriedades psicométricas do American Orthopaedic Foot and Ankle Society Score (Aofas em pacientes com artrite reumatoide: aplicação do modelo Rasch

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    Cristiano Sena da Conceição

    2016-02-01

    Full Text Available Resumo Objetivo: Testar a confiabilidade e a validade do escore Aofas em uma amostra de pacientes com artrite reumatoide. Métodos: A escala foi aplicada a pacientes com artrite reumatoide, duas vezes pelo entrevistador 1 e uma vez pelo entrevistador 2. O Aofas foi submetido a exame de confiabilidade teste-reteste (com 20 indivíduos com artrite reumatoide. As propriedades psicométricas foram investigadas pela análise Rasch em 33 pacientes com artrite reumatoide. Resultados: O coeficiente de correlação intraclasse (CCI foi de 0,90 < CCI < 0,95 (p < 0,001 para a confiabilidade intraexaminador e 0,75 < CCI < 0,91 (p < 0,001 para a confiabilidade interexaminador. O índice de separação dos indivíduos foi de 1,9 e 4,75 para os itens. Isso demonstra que os pacientes se dividiam em três níveis de habilidade e os itens foram divididos em seis níveis de dificuldades. A análise Rasch mostrou que oito itens foram satisfatórios. Foi identificado um item errôneo, que mostrou percentuais acima dos 5% permitidos pelo modelo estatístico. Além disso, o modelo Rasch sugeriu a revisão do item 8 original. Conclusões: Os resultados sugerem que a versão brasileira do Aofas apresenta confiabilidade adequada, validade de constructo e estabilidade de resposta. Esses resultados indicam que a escala de tornozelo-retropé Aofas apresenta um potencial significativo de aplicabilidade clínica em indivíduos com artrite reumatoide. Outros estudos em populações com outras características já estão em andamento.

  18. Uso del modelo de Rasch para la construcción de tablas de especificaciones: Propuesta metodológica aplicada a una prueba de selección universitaria

    OpenAIRE

    Cerdas Núñez, Danny; Montero Rojas, Eiliana

    2017-01-01

    Mediante un enfoque cuantitativo y un análisis descriptivo de investigación, este artículo presenta una aplicación menos conocida del modelo Rasch, como herramienta técnica para la construcción y validación de tablas de especificaciones para pruebas estandarizadas. El estudio hace una propuesta para generar, empleando este modelo, y una con mayor rugosidad científica, una tabla de especificaciones en términos de procesos y contenidos para el componente de razonamiento en contextos matemáticos...

  19. Rapamycin combined with anti-CD45RB mAb and IL-10 or with G-CSF induces tolerance in a stringent mouse model of islet transplantation.

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    Nicola Gagliani

    Full Text Available BACKGROUND: A large pool of preexisting alloreactive effector T cells can cause allogeneic graft rejection following transplantation. However, it is possible to induce transplant tolerance by altering the balance between effector and regulatory T (Treg cells. Among the various Treg-cell types, Foxp3(+Treg and IL-10-producing T regulatory type 1 (Tr1 cells have frequently been associated with tolerance following transplantation in both mice and humans. Previously, we demonstrated that rapamycin+IL-10 promotes Tr1-cell-associated tolerance in Balb/c mice transplanted with C57BL/6 pancreatic islets. However, this same treatment was unsuccessful in C57BL/6 mice transplanted with Balb/c islets (classified as a stringent transplant model. We accordingly designed a protocol that would be effective in the latter transplant model by simultaneously depleting effector T cells and fostering production of Treg cells. We additionally developed and tested a clinically translatable protocol that used no depleting agent. METHODOLOGY/PRINCIPAL FINDINGS: Diabetic C57BL/6 mice were transplanted with Balb/c pancreatic islets. Recipient mice transiently treated with anti-CD45RB mAb+rapamycin+IL-10 developed antigen-specific tolerance. During treatment, Foxp3(+Treg cells were momentarily enriched in the blood, followed by accumulation in the graft and draining lymph node, whereas CD4(+IL-10(+IL-4(- T (i.e., Tr1 cells localized in the spleen. In long-term tolerant mice, only CD4(+IL-10(+IL-4(- T cells remained enriched in the spleen and IL-10 was key in the maintenance of tolerance. Alternatively, recipient mice were treated with two compounds routinely used in the clinic (namely, rapamycin and G-CSF; this drug combination promoted tolerance associated with CD4(+IL-10(+IL-4(- T cells. CONCLUSIONS/SIGNIFICANCE: The anti-CD45RB mAb+rapamycin+IL-10 combined protocol promotes a state of tolerance that is IL-10 dependent. Moreover, the combination of rapamycin+G-CSF induces

  20. Tc-99m-bicisate (ECD)-brain-SPECT in rapidly progressive dementia; Hirn-SPECT mit Tc-99m-Bicisat (ECD) bei rasch progredientem dementiellen Syndrom

    Energy Technology Data Exchange (ETDEWEB)

    Marienhagen, J.; Eilles, C. [Regensburg Univ. (Germany). Abt. fuer Nuklearmedizin; Weingaertner, U.; Blaha, L. [Bezirkskrankenhaus Mainkofen (Germany). Psychiatrische Klinik; Zerr, I.; Poser, S. [Goettingen Univ. (Germany). Klinik und Poliklinik fuer Neurologie

    1999-07-01

    We present a 61-year-old male patient with progressive dementia. A brain SPECT with Tc-99m-bicisate was performed for confirmation of clinically suspected Alzheimer-dementia. At the time of the SPECT-investigation marked apraxia and aphasia besides severe dementia were present. Electrophysiological as well as anatomical neuroimaging findings showed non-diagnostic alterations. SPECT revealed distinct perfusion defects, which made Alzheimer Dementia unlikely. The further course of the patient was determined by rapidly progressive deterioration with development of akinetic mutism. Thereafter, increased levels of neuron-specific enolase as well as 14-3-3 proteins were found in the cerebro-spinal fluid (CSF). The patient finally died with signs of cerebral decortication. Due to the clinical course and the CSF-findings the patient's final diagnosis was Creutzfeld-Jakob-disease, nevertheless no autopsy was performed. The presented case report underscores the clinical utility of perfusion brain SPECT in the differential diagnosis of dementias. (orig.) [German] Wir berichten ueber einen 61jaehrigen Patienten mit progredientem dementiellen Syndrom, der unter der Verdachtsdiagnose einer Demenz vom Alzheimer-Typ (DAT) zur Hirn-SPECT-Untersuchung mit TC-99m-Bicisat (ECD) vorgestellt wurde. Zum Untersuchungszeitpunkt bestanden neben dem Vollbild einer Demenz eine ausgepraegte Apraxie und Aphasie bei unspezifischen Veraenderungen im EEG sowie der neuroradiologischen Bildgebung. In der Hirn-SPECT-Untersuchung fanden sich fuer eine DAT untypische ausgedehnte, vorwiegend rechtshemisphaerische Perfusionsstoerungen. Im weiteren Verlauf rasche Progredienz des Krankheitsbildes mit Entwicklung eines akinetischen Mutismus sowie Nachweis erhoehter Werte der neuronspezifischen Enolase und des 14-3-3-Proteins im Liquor. Der Patient verstarb schliesslich unter dem Bild einer Decortication. Aufgrund des klinischen Verlaufs sowie der Liquorbefunde wurde, da eine autoptische Befundsicherung

  1. Rasch techniques for detecting bias in performance assessments: an example comparing the performance of native and non-native speakers on a test of academic English.

    Science.gov (United States)

    Elder, Catherine; McNamara, Tim; Congdon, Peter

    2003-01-01

    The use of common tasks and rating procedures when assessing the communicative skills of students from highly diverse linguistic and cultural backgrounds poses particular measurement challenges, which have thus far received little research attention. If assessment tasks or criteria are found to function differentially for particular subpopulations within a test candidature with the same or a similar level of criterion ability, then the test is open to charges of bias in favour of one or other group. While there have been numerous studies involving dichotomous language test items (see e.g. Chen and Henning, 1985 and more recently Elder, 1996) few studies have considered the issue of bias in relation to performance based tasks which are assessed subjectively, via analytic and holistic rating scales. The paper demonstrates how Rasch analytic procedures can be applied to the investigation of item bias or differential item functioning (DIF) in both dichotomous and scalar items on a test of English for academic purposes. The data were gathered from a pilot English language test administered to a representative sample of undergraduate students (N= 139) enrolled in their first year of study at an English-medium university. The sample included native speakers of English who had completed up to 12 years of secondary schooling in their first language (L1) and immigrant students, mainly from Asian language backgrounds, with varying degrees of prior English language instruction and exposure. The purpose of the test was to diagnose the academic English needs of incoming undergraduates so that additional support could be offered to those deemed at risk of failure in their university study. Some of the tasks included in the assessment procedure involved objectively-scored items (measuring vocabulary knowledge, text-editing skills and reading and listening comprehension) whereas others (i.e. a report and an argumentative writing task) were subjectively-scored. The study models a

  2. Rasch modelling of Mathematics and Science teachers’ preferences of real-life situations to be used in Mathematical Literacy

    Directory of Open Access Journals (Sweden)

    Cyril Julie

    2011-10-01

    Full Text Available In order to ascertain the real-life situations that teachers, as stakeholders, would find suitable and appropriate to deal with in Mathematical Literacy (a compulsory subject for students who are not doing Mathematics at the Further Education and Training level of the South African education system, we embarked on a study known as the Relevance of School Mathematics Education (ROSME. The principle underpinning this article is that there are times when it is necessary to assess the functionality and quality of questionnaires used to ascertain affective domain issues. The study provides an analysis technique which is not affected by the sample of individuals completing a questionnaire, provided that the instrument meets particular requirements. It thus improves the rigour of measurement. Various statistics obtained in this study showed that the instrument used to determine the real-life situations which teachers prefer for Mathematical Literacy reasonably identifies this variable. However, it is cautioned that much more care needs to be exercised in construction of such instruments. The results also indicated the real-life situations which teachers most and least preferred to be included in Mathematical Literacy, providing useful information for policy-makers and textbook authors on contextual situations to be included in learning materials.

  3. Cross-diagnostic validity of the SF-36 physical functioning scale in patients with stroke, multiple sclerosis and amyotrophic lateral sclerosis: a study using Rasch analysis

    NARCIS (Netherlands)

    Dallmeijer, Annet J.; de Groot, Vincent; Roorda, Leo D.; Schepers, Vera P. M.; Lindeman, Eline; van den Berg, Leonard H.; Beelen, Anita; Dekker, Joost

    2007-01-01

    The aim of this study was to investigate unidimensionality and differential item functioning of the SF-36 physical functioning scale (PF10) in patients with various neurological disorders. Patients: Patients post-stroke (n = 198), with multiple sclerosis (n = 151) and amyotrophic lateral sclerosis

  4. Item analysis using Rasch models confirms that the Danish versions of the DISABKIDS (R) chronic-generic and diabetes-specific modules are valid and reliable

    DEFF Research Database (Denmark)

    Nielsen, Julie Bøjstrup; Kyvsgaard, Julie Nyholm; Sildorf, Stine Møller

    2017-01-01

    and diabetes-specific validated multinational DISABKIDS® questionnaires into Danish, and then determine their validity and reliability. Methods: The questionnaires were translated using a validated translation procedure and completed by 99 children and adolescents from our diabetes-department; all diagnosed......Background: Type 1 Diabetes (T1D) has a negative impact on psychological and overall well-being. Screening for Health-related Quality of Life (HrQoL) and addressing HrQoL issues in the clinic leads to improved well-being and metabolic outcomes. The aim of this study was to translate the generic...

  5. How Should We Assess the Fit of Rasch-Type Models? Approximating the Power of Goodness-of-Fit Statistics in Categorical Data Analysis

    Science.gov (United States)

    Maydeu-Olivares, Alberto; Montano, Rosa

    2013-01-01

    We investigate the performance of three statistics, R [subscript 1], R [subscript 2] (Glas in "Psychometrika" 53:525-546, 1988), and M [subscript 2] (Maydeu-Olivares & Joe in "J. Am. Stat. Assoc." 100:1009-1020, 2005, "Psychometrika" 71:713-732, 2006) to assess the overall fit of a one-parameter logistic model…

  6. Evaluation of the Parent-Report Inventory of Callous-Unemotional Traits in a Sample of Children Recruited from Intimate Partner Violence Services: A Multidimensional Rasch Analysis.

    Science.gov (United States)

    McDonald, Shelby Elaine; Ma, Lin; Green, Kathy E; Hitti, Stephanie A; Cody, Anna M; Donovan, Courtney; Williams, James Herbert; Ascione, Frank R

    2018-03-01

    Our study applied multidimensional item response theory (MIRT) to compare structural models of the parent-report version of the Inventory of Callous and Unemotional Traits (ICU; English and North American Spanish translations). A total of 291 maternal caregivers were recruited from community-based domestic violence services and reported on their children (77.9% ethnic minority; 47% female), who ranged in age from 7 to 12 years (mean = 9.07, standard deviation = 1.64). We compared 9 models that were based on prior psychometric evaluations of the ICU. MIRT analyses indicated that a revised 18-item version comprising 2 factors (callous-unemotional and empathic-prosocial) was more suitable for our sample. Differential item functioning was found for several items across ethnic and language groups, but not for child gender or age. Evidence of construct validity was found. We recommend continued research and revisions to the ICU to better assess the presence of callous-unemotional traits in community samples of school-age children. © 2017 Wiley Periodicals, Inc.

  7. Spinal Cord Independence Measure, version III: applicability to the UK spinal cord injured population.

    Science.gov (United States)

    Glass, Clive A; Tesio, Luigi; Itzkovich, Malka; Soni, Bakul M; Silva, Pedro; Mecci, Munawar; Chadwick, Raymond; el Masry, Waghi; Osman, Aheed; Savic, Gordana; Gardner, Brian; Bergström, Ebba; Catz, Amiram

    2009-09-01

    To examine the validity, reliability and usefulness of the Spinal Cord Independence Measure for the UK spinal cord injury population. Multi-centre cohort study. Four UK regional spinal cord injury centres. Eighty-six people with spinal cord injury. Spinal Cord Independence Measure and Functional Independence Measure on admission analysed using inferential statistics, and Rasch analysis of Spinal Cord Independence Measure. Internal consistency, inter-rater reliability, discriminant validity; Spinal Cord Independence Measure subscale match between distribution of item difficulty and patient ability measurements; reliability of patient ability measures; fit of data to Rasch model; unidimensionality of subscales; hierarchical ordering of categories within items; differential item functioning across patient groups. Scale reliability (kappa coefficients range 0.491-0.835; (p Spinal Cord Independence Measure subscales compatible with stringent Rasch requirements; mean infit indices high; distinct strata of abilities identified; most thresholds ordered; item hierarchy stable across clinical groups and centres. Misfit and differences in item hierarchy identified. Difficulties assessing central cord injuries highlighted. Conventional statistical and Rasch analyses justify the use of the Spinal Cord Independence Measure in clinical practice and research in the UK. Cross-cultural validity may be further improved.

  8. ltm: An R Package for Latent Variable Modeling and Item Response Analysis

    Directory of Open Access Journals (Sweden)

    Dimitris Rizopoulos

    2006-11-01

    Full Text Available The R package ltm has been developed for the analysis of multivariate dichotomous and polytomous data using latent variable models, under the Item Response Theory approach. For dichotomous data the Rasch, the Two-Parameter Logistic, and Birnbaum's Three-Parameter models have been implemented, whereas for polytomous data Semejima's Graded Response model is available. Parameter estimates are obtained under marginal maximum likelihood using the Gauss-Hermite quadrature rule. The capabilities and features of the package are illustrated using two real data examples.

  9. Crystallization of a stringent response factor from Aquifex aeolicus

    DEFF Research Database (Denmark)

    Kristensen, Ole; Laurberg, Martin; Gajhede, Michael

    2002-01-01

    a = 50.8, b = 70.3, c = 90.9 A. Methionine residues were introduced by mutation and deliberate oxidation of the protein allowed us to produce additional crystal forms with reproducible diffraction ability and increased phasing potential. This is the first report on the crystallization of a member...

  10. Stringent cost management and preservation of safety culture, a contradiction?

    International Nuclear Information System (INIS)

    Petersen, Klaus; Pamme, H.

    2002-01-01

    Full text: Competition in the deregulated electricity market does not leave nuclear power plants unaffected. Hence the question is to answer, whether the safety is going to suffer under the cost pressure on the market. Therefore the target of NPP operator's cost management is to run plants at maximum availability and with optimized cost structures that lead to minimized specific generating costs. The c osts of safety , with their fixed-cost character, are elements of this cost structure. The process of economic optimization of the cost structure does not permit cost minimization on its own sake in the area of operation cost and fuel cost (front and back end). The basis of economical assessment rather must be the minimization of potential risks which could entail losses of availability. However, many investments like plant modifications or preventive maintenance efforts made in order to avoid losses of availability to a large extent also imply at least a preservation or even higher levels of safety. Thus, economic efficiency and safety are closely correlated. Public opinion is very sensible as soon as the high level of plant safety seems to be touched by economic pressure. But realizing that German NPP are endowed with mature design and safety features, improvements of safety standards can only marginally be increased by further technical optimizations. Therefore plant management, man-machine-interface and the individual behaviour of the employees are targets for improvement of nuclear safety and economic efficiency by increasing the efficiency of processes. An even more efficient use of scarce funds and a tolerable political environment should allow the safety level of NPP to be upheld, and safety culture could be maintained and even be improved. (author)

  11. Crystallization of a stringent response factor from Aquifex aeolicus

    DEFF Research Database (Denmark)

    Kristensen, Ole; Laurberg, Martin; Gajhede, Michael

    2002-01-01

    a = 50.8, b = 70.3, c = 90.9 A. Methionine residues were introduced by mutation and deliberate oxidation of the protein allowed us to produce additional crystal forms with reproducible diffraction ability and increased phasing potential. This is the first report on the crystallization of a member...... of the Ppx/GppA phosphatase family....

  12. A report on the CCNA 2007 professional practice analysis.

    Science.gov (United States)

    Muckle, Timothy J; Apatov, Nathaniel M; Plaus, Karen

    2009-06-01

    The purpose of this column is to present the results of the 2007 Professional Practice Analysis (PPA) of the field of nurse anesthesia, conducted by the Council on Certification of Nurse Anesthetists. The PPA used survey and rating scale methodologies to collect data regarding the relative emphasis of various aspects of the nurse anesthesia knowledge domain and competencies. A total of 3,805 survey responses were analyzed using the Rasch rating scale model, which aggregates and transforms ordinal (rating scale) responses into linear measures of relative importance and frequency. Summaries of respondent demographics and educational and professional background are provided, as well as descriptions of how the survey results are used to develop test specifications. The results of this analysis provide evidence for the content outline and test specifications (content percentages) and thus serve as a basis of content validation for the National Certification Examination.

  13. Hierarchical Generalized Linear Models for the Analysis of Judge Ratings

    Science.gov (United States)

    Muckle, Timothy J.; Karabatsos, George

    2009-01-01

    It is known that the Rasch model is a special two-level hierarchical generalized linear model (HGLM). This article demonstrates that the many-faceted Rasch model (MFRM) is also a special case of the two-level HGLM, with a random intercept representing examinee ability on a test, and fixed effects for the test items, judges, and possibly other…

  14. European Climate - Energy Security Nexus. A model based scenario analysis

    International Nuclear Information System (INIS)

    Criqui, Patrick; Mima, Silvana

    2011-01-01

    In this research, we have provided an overview of the climate-security nexus in the European sector through a model based scenario analysis with POLES model. The analysis underline that under stringent climate policies, Europe take advantage of a double dividend in its capacity to develop a new cleaner energy model and in lower vulnerability to potential shocks on the international energy markets. (authors)

  15. European Climate - Energy Security Nexus. A model based scenario analysis

    Energy Technology Data Exchange (ETDEWEB)

    Criqui, Patrick; Mima, Silvana

    2011-01-15

    In this research, we have provided an overview of the climate-security nexus in the European sector through a model based scenario analysis with POLES model. The analysis underline that under stringent climate policies, Europe take advantage of a double dividend in its capacity to develop a new cleaner energy model and in lower vulnerability to potential shocks on the international energy markets. (authors)

  16. Assessing normative cut points through differential item functioning analysis: An example from the adaptation of the Middlesex Elderly Assessment of Mental State (MEAMS for use as a cognitive screening test in Turkey

    Directory of Open Access Journals (Sweden)

    Kutlay Sehim

    2006-03-01

    Full Text Available Abstract Background The Middlesex Elderly Assessment of Mental State (MEAMS was developed as a screening test to detect cognitive impairment in the elderly. It includes 12 subtests, each having a 'pass score'. A series of tasks were undertaken to adapt the measure for use in the adult population in Turkey and to determine the validity of existing cut points for passing subtests, given the wide range of educational level in the Turkish population. This study focuses on identifying and validating the scoring system of the MEAMS for Turkish adult population. Methods After the translation procedure, 350 normal subjects and 158 acquired brain injury patients were assessed by the Turkish version of MEAMS. Initially, appropriate pass scores for the normal population were determined through ANOVA post-hoc tests according to age, gender and education. Rasch analysis was then used to test the internal construct validity of the scale and the validity of the cut points for pass scores on the pooled data by using Differential Item Functioning (DIF analysis within the framework of the Rasch model. Results Data with the initially modified pass scores were analyzed. DIF was found for certain subtests by age and education, but not for gender. Following this, pass scores were further adjusted and data re-fitted to the model. All subtests were found to fit the Rasch model (mean item fit 0.184, SD 0.319; person fit -0.224, SD 0.557 and DIF was then found to be absent. Thus the final pass scores for all subtests were determined. Conclusion The MEAMS offers a valid assessment of cognitive state for the adult Turkish population, and the revised cut points accommodate for age and education. Further studies are required to ascertain the validity in different diagnostic groups.

  17. Compreensão da leitura: análise do funcionamento diferencial dos itens de um Teste de Cloze Reading comprehension: differential item functioning analysis of a Cloze Test

    Directory of Open Access Journals (Sweden)

    Katya Luciane Oliveira

    2012-01-01

    Full Text Available Este estudo teve por objetivos investigar o ajuste de um Teste de Cloze ao modelo Rasch e avaliar a dificuldade na resposta ao item em razão do gênero das pessoas (DIF. Participaram da pesquisa 573 alunos das 5ª a 8ª séries do ensino fundamental de escolas públicas estaduais dos estados de São Paulo e Minas Gerais. O teste de Cloze foi aplicado de forma coletiva. A análise do instrumento evidenciou um bom ajuste ao modelo Rasch, bem como os itens foram respondidos conforme o padrão esperado, demonstrando um bom ajuste, também. Quanto ao DIF, apenas três itens indicaram diferenciar o gênero. Com base nos dados, identificou-se que houve equilíbrio nas respostas dadas pelos meninos e meninas.The objectives of the present study were to investigate the adaptation of a Cloze test to the Rasch Model as well as to evaluate the Differential Item Functioning (DIF in relation to gender. The sample was composed by 573 students from 5th to 8th grades of public schools in the state of São Paulo. The cloze test was applied collectively. The analysis of the instrument revealed its adaptation to Rash Model and that the items were responded according to the expected pattern, showing good adjustment, as well. Regarding DIF, only three items were differentiated by gender. Based on the data, results indicated a balance in the answers given by boys and girls.

  18. The Use of Categorical Variables in Data Envelopment Analysis

    OpenAIRE

    Rajiv D. Banker; Richard C. Morey

    1986-01-01

    Data Envelopment Analysis has now been extensively applied in a range of empirical settings to identify relative inefficiencies, and provide targets for improvements. It accomplishes this by developing peer groups for each unit being operated. The use of categorical variables is an important extension which can improve the peer group construction process and incorporate "on-off" characteristics, e.g., presence of drive-in window or not in a banking network. It relaxes the stringent need for f...

  19. Measuring functioning in people with fibromyalgia (FM) based on the international classification of functioning, disability and health (ICF)--a psychometric analysis.

    Science.gov (United States)

    Prodinger, Birgit; Salzberger, Thomas; Stucki, Gerold; Stamm, Tanja; Cieza, Alarcos

    2012-04-01

    Instruments to assess functioning in patients with FM vary considerably in their content and are often symptom-specific. This study aimed to examine whether it is feasible to construct a psychometric-sound clinical instrument to measure functioning in FM based on the Brief ICF-Core-Set for chronic widespread pain (CWP). Two hundred and fifty six people with FM completed the Brief ICF-Core-Set. The Rasch model was used for analysis. Once ordering of response options of ICF categories was ensured, the following properties were studied: fit of the ICF categories to the Rasch model, the targeting between ICF categories and a person's abilities, unidimensionality, and reliability. Six ICF categories were rescored due to disordered thresholds. Five ICF categories were removed due to high model-misfit and differential item functioning (DIF) for gender. Scores from 46 participants were excluded due to extreme scores. The ICF categories included display consistency with an underlying unidimensional construct, are free of DIF for age, disease duration and gender, display excellent overall reliability, and cover a range of functioning difficulties. This study illustrates that it is possible to measure functioning as a unidimensional construct based on selected ICF categories from the components body functions, as well as activities and participation of the Brief ICF-Core-Set for CWP in patients with FM. © 2011 The Authors. Pain Practice © 2011 World Institute of Pain.

  20. Analysis

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Liu, Wen; Zhang, Xiliang

    2014-01-01

    three major technological changes: energy savings on the demand side, efficiency improvements in energy production, and the replacement of fossil fuels by various sources of renewable energy. Consequently, the analysis of these systems must include strategies for integrating renewable sources...

  1. Rasch models with exchangeable rows and columns

    DEFF Research Database (Denmark)

    Lauritzen, Steffen Lilholt

    The article studies distributions of doubly infinite binary matrices with exchangeable rows and columns which satify the further property that the probability of any $m \\times n$ submatrix is a function of the row- and column sums of that matrix. We show that any such distribution is a (unique...

  2. Refining Change Measure with the Rasch Model

    Science.gov (United States)

    Zaporozhets, Olga; Fox, Christine M.; Beltyukova, Svetlana A.; Laux, John M.; Piazza, Nick J.; Salyers, Kathleen

    2015-01-01

    This study was to develop a linear measure of change using University of Rhode Island Change Assessment items that represented Prochaska and DiClemente's theory. The resulting Toledo Measure of Change is short, is easy to use, and provides reliable scores for identification of individuals' stage of change and progression within that stage.

  3. Computerized Classification Testing with the Rasch Model

    Science.gov (United States)

    Eggen, Theo J. H. M.

    2011-01-01

    If classification in a limited number of categories is the purpose of testing, computerized adaptive tests (CATs) with algorithms based on sequential statistical testing perform better than estimation-based CATs (e.g., Eggen & Straetmans, 2000). In these computerized classification tests (CCTs), the Sequential Probability Ratio Test (SPRT) (Wald,…

  4. Analysis

    CERN Document Server

    Maurin, Krzysztof

    1980-01-01

    The extraordinarily rapid advances made in mathematics since World War II have resulted in analysis becoming an enormous organism spread­ ing in all directions. Gone for good surely are the days of the great French "courses of analysis" which embodied the whole of the "ana­ lytical" knowledge of the times in three volumes-as the classical work of Camille Jordan. Perhaps that is why present-day textbooks of anal­ ysis are disproportionately modest relative to the present state of the art. More: they have "retreated" to the state before Jordan and Goursat. In recent years the scene has been changing rapidly: Jean Dieudon­ ne is offering us his monumentel Elements d'Analyse (10 volumes) written in the spirit of the great French Course d'Analyse. To the best of my knowledge, the present book is the only one of its size: starting from scratch-from rational numbers, to be precise-it goes on to the theory of distributions, direct integrals, analysis on com­ plex manifolds, Kahler manifolds, the theory of sheave...

  5. Comparative Study of Middle School Students' Attitudes towards Science: Rasch Analysis of Entire TIMSS 2011 Attitudinal Data for England, Singapore and the U.S.A. as Well as Psychometric Properties of Attitudes Scale

    Science.gov (United States)

    Oon, Pey Tee; Subramaniam, R.

    2018-01-01

    We report here on a comparative study of middle school students' attitudes towards science involving three countries: England, Singapore and the U.S.A. Complete attitudinal data sets from TIMSS (Trends in International Mathematics and Science Study) 2011 were used, thus giving a very large sample size (N = 20,246), compared to other studies in the…

  6. Validation of the Dutch version of the Swallowing Quality-of-Life Questionnaire (DSWAL-QoL) and the adjusted DSWAL-QoL (aDSWAL-QoL) using item analysis with the Rasch model

    DEFF Research Database (Denmark)

    Simpelaere, Ingeborg S.; Van Nuffelen, Gwen; De Bodt, Marc

    2017-01-01

    Background The Swallowing Quality-of-Life Questionnaire (SWAL-QoL) is considered the gold standard for assessing health-related QoL in oropharyngeal dysphagia. The Dutch translation (DSWAL-QoL) and its adjusted version (aDSWAL-QoL) have been validated using classical test theory (CTT). However...

  7. Relationship Between Patients' Perceptions of Care Quality and Health Care Errors in 11 Countries: A Secondary Data Analysis.

    Science.gov (United States)

    Hincapie, Ana L; Slack, Marion; Malone, Daniel C; MacKinnon, Neil J; Warholak, Terri L

    2016-01-01

    Patients may be the most reliable reporters of some aspects of the health care process; their perspectives should be considered when pursuing changes to improve patient safety. The authors evaluated the association between patients' perceived health care quality and self-reported medical, medication, and laboratory errors in a multinational sample. The analysis was conducted using the 2010 Commonwealth Fund International Health Policy Survey, a multinational consumer survey conducted in 11 countries. Quality of care was measured by a multifaceted construct developed using Rasch techniques. After adjusting for potentially important confounding variables, an increase in respondents' perceptions of care coordination decreased the odds of self-reporting medical errors, medication errors, and laboratory errors (P < .001). As health care stakeholders continue to search for initiatives that improve care experiences and outcomes, this study's results emphasize the importance of guaranteeing integrated care.

  8. Volume 42, Issue5 (May 2005)Articles in the Current Issue:Developmental growth in students' concept of energy: Analysis of selected items from the TIMSS database

    Science.gov (United States)

    Liu, Xiufeng; McKeough, Anne

    2005-05-01

    The aim of this study was to develop a model of students' energy concept development. Applying Case's (1985, 1992) structural theory of cognitive development, we hypothesized that students' concept of energy undergoes a series of transitions, corresponding to systematic increases in working memory capacity. The US national sample from the Third International Mathematics and Science Study (TIMSS) database was used to test our hypothesis. Items relevant to the energy concept in the TIMSS test booklets for three populations were identified. Item difficulty from Rasch modeling was used to test the hypothesized developmental sequence, and percentage of students' correct responses was used to test the correspondence between students' age/grade level and level of the energy concepts. The analysis supported our hypothesized sequence of energy concept development and suggested mixed effects of maturation and schooling on energy concept development. Further, the results suggest that curriculum and instruction design take into consideration the developmental progression of students' concept of energy.

  9. Reliability analysis of microcomputer boards and computer based systems important to safety of nuclear plants

    International Nuclear Information System (INIS)

    Shrikhande, S.V.; Patil, V.K.; Ganesh, G.; Biswas, B.; Patil, R.K.

    2010-01-01

    Computer Based Systems (CBS) are employed in Indian nuclear plants for protection, control and monitoring purpose. For forthcoming CBS, Reactor Control Division has designed and developed a new standardized family of microcomputer boards qualified to stringent requirements of nuclear industry. These boards form the basic building blocks of CBS. Reliability analysis of these boards is being carried out using analysis package based on MIL-STD-217Plus methodology. The estimated failure rate values of these standardized microcomputer boards will be useful for reliability assessment of these systems. The paper presents reliability analysis of microcomputer boards and case study of a CBS system built using these boards. (author)

  10. An energy-economic scenario analysis of alternative fuels for personal transport using the Global Multi-regional MARKAL model (GMM)

    International Nuclear Information System (INIS)

    Guel, Timur; Kypreos, Socrates; Turton, Hal; Barreto, Leonardo

    2009-01-01

    This paper deals with the long-term prospects of alternative fuels in global personal transport. It aims at assessing key drivers and key bottlenecks for their deployment, focusing particularly on the role of biofuels and hydrogen in meeting climate policy objectives. The analysis is pursued using the Global Multi-regional MARKAL model (GMM), a perfect foresight 'bottom-up' model of the global energy system with a detailed representation of alternative fuel chains, linked to the Model for the Assessment of Greenhouse Gas Induced Climate Change (MAGICC). The analysis shows that biofuels are limited by the regional availability of low-cost biomass, but can be important for meeting mild climate policy targets. If policy-makers intend to pursue more stringent climate policy, then hydrogen becomes a competitive option. However, the analysis finds that the use of hydrogen in personal transport is restricted to very stringent climate policy, as only such policy provides enough incentive to build up the required delivery infrastructure. An analysis of costs additionally shows that 'keeping the hydrogen option open' does not take considerable investments compared to the investment needs in the power sector within the next decades, but allows the use of hydrogen for the pursuit of stringent climate policy in the second half of the century.

  11. Dimensionality of the UWES-17: An item response modelling analysis

    Directory of Open Access Journals (Sweden)

    Deon P. de Bruin

    2013-10-01

    Research purpose: The main focus of this study was to use the Rasch model to provide insight into the dimensionality of the UWES-17, and to assess whether work engagement should be interpreted as one single overall score, three separate scores, or a combination. Motivation for the study: It is unclear whether a summative score is more representative of work engagement or whether scores are more meaningful when interpreted for each dimension separately. Previous work relied on confirmatory factor analysis; the potential of item response models has not been tapped. Research design: A quantitative cross-sectional survey design approach was used. Participants, 2429 employees of a South African Information and Communication Technology (ICT company, completed the UWES-17. Main findings: Findings indicate that work engagement should be treated as a unidimensional construct: individual scores should be interpreted in a summative manner, giving a single global score. Practical/managerial implications: Users of the UWES-17 may interpret a single, summative score for work engagement. Findings of this study should also contribute towards standardising UWES-17 scores, allowing meaningful comparisons to be made. Contribution/value-add: The findings will benefit researchers, organisational consultants and managers. Clarity on dimensionality and interpretation of work engagement will assist researchers in future studies. Managers and consultants will be able to make better-informed decisions when using work engagement data.

  12. Elemental analysis of hair using PIXE-tomography and INAA

    International Nuclear Information System (INIS)

    Beasley, D.; Gomez-Morilla, I.; Spyrou, N.

    2008-01-01

    3D quantitative elemental maps of a section of a strand of hair were produced using a combination of PIXE-Tomography and simultaneous On/Off Axis STIM-Tomography at the University of Surrey Ion Beam Centre. The distributions of S, K, Cl, Ca, Fe and Zn were determined using the PIXE-T reconstruction package DISRA. The results were compared with conventional bulk PIXE analysis of tomographic data as determined using Dan32. The overall concentrations determined by PIXE were compared with elemental concentrations held in the University of Surrey Hair Database. All the entries currently in the database were produced using INAA. The merits and possible contributions of tomographic PIXE analysis to analysis of hair are discussed. The conclusions drawn from the PIXE-Tomography analysis can be used to argue for more stringent procedures for hair analysis at the University of Surrey. (author)

  13. Oswestry Disability Index: a psychometric analysis with 1,610 patients.

    Science.gov (United States)

    Brodke, Darrel S; Goz, Vadim; Lawrence, Brandon D; Spiker, W Ryan; Neese, Ashley; Hung, Man

    2017-03-01

    One-fourth of the adult US population has or will experience back pain and has undergone one of a myriad of treatments. Understanding the outcomes of these many treatments from pharmacologic to surgical, from manipulation to modality, allows for a better understanding and value-driven decision making. Patient-reported outcome measures are the current standard and include general and disease-specific measures. The Oswestry Disability Index (ODI) is the most commonly used disease-specific patient-reported outcome tool to measure functional disability related to back pain. Few studies have evaluated its psychometric properties in a large patient sample using a modern tool such as the Rasch analysis model. This study aims to identify the benefits and deficiencies of the ODI as an outcome tool for assessing patients with back pain. This study aimed to investigate the psychometric properties, performance, and applicability of the ODI in patients with back pain who visited a university-based outpatient clinic. This study used a secondary analysis-assessment of diagnostic tool on consecutive patients. The sample comprised 1,610 patients visiting an academic spine center. The ODI was the outcome measure. Detailed Rasch analysis of the ODI was performed. Standard descriptive statistics were also assessed. The ODI performed well overall. It demonstrated suboptimal unidimensionality (ie, unexplained variance after accounting for the first dimension) of 8.3%. Person reliability was good, at 0.85, and item reliability was excellent, at 1.00. The overall item fit for the ODI was good with an outfit mean square of 1.02. The ODI had a floor effect of 29.9% and ceiling effect of 3.9%. The raw score to measure correlation of the ODI was excellent, at 0.944. The ODI performed relatively well overall, with some problematic findings. It had good person and item reliability, although it did not demonstrate strong evidence of unidimensionality. The ODI has moderately poor coverage, with a

  14. Rapid species responses to changes in climate require stringent climate protection targets

    NARCIS (Netherlands)

    Vliet, van A.J.H.; Leemans, R.

    2006-01-01

    The Avoiding Dangerous Climate Change book consolidates the scientific findings of the Exeter conference and gives an account of the most recent developments on critical thresholds and key vulnerabilities of the climate system, impacts on human and natural systems, emission pathways and

  15. Mandatory Disclosure of Blockholders and Related Party Transactions : Stringent Versus Flexible Rules

    NARCIS (Netherlands)

    McCahery, J.A.; Vermeulen, E.P.M.

    2011-01-01

    Investor confidence in financial markets depends in large part on the existence of an accurate disclosure and reporting regime that provides transparency in the beneficial ownership and control structures of publicly listed companies. Today, a common post-financial crisis regulatory reform theme is

  16. Moderate forest disturbance as a stringent test for gap and big-leaf models

    Science.gov (United States)

    Bond-Lamberty, B.; Fisk, J. P.; Holm, J. A.; Bailey, V.; Bohrer, G.; Gough, C. M.

    2015-01-01

    Disturbance-induced tree mortality is a key factor regulating the carbon balance of a forest, but tree mortality and its subsequent effects are poorly represented processes in terrestrial ecosystem models. It is thus unclear whether models can robustly simulate moderate (non-catastrophic) disturbances, which tend to increase biological and structural complexity and are increasingly common in aging US forests. We tested whether three forest ecosystem models - Biome-BGC (BioGeochemical Cycles), a classic big-leaf model, and the ZELIG and ED (Ecosystem Demography) gap-oriented models - could reproduce the resilience to moderate disturbance observed in an experimentally manipulated forest (the Forest Accelerated Succession Experiment in northern Michigan, USA, in which 38% of canopy dominants were stem girdled and compared to control plots). Each model was parameterized, spun up, and disturbed following similar protocols and run for 5 years post-disturbance. The models replicated observed declines in aboveground biomass well. Biome-BGC captured the timing and rebound of observed leaf area index (LAI), while ZELIG and ED correctly estimated the magnitude of LAI decline. None of the models fully captured the observed post-disturbance C fluxes, in particular gross primary production or net primary production (NPP). Biome-BGC NPP was correctly resilient but for the wrong reasons, and could not match the absolute observational values. ZELIG and ED, in contrast, exhibited large, unobserved drops in NPP and net ecosystem production. The biological mechanisms proposed to explain the observed rapid resilience of the C cycle are typically not incorporated by these or other models. It is thus an open question whether most ecosystem models will simulate correctly the gradual and less extensive tree mortality characteristic of moderate disturbances.

  17. Stringent factor and proteolysis control of sigma factor RpoS expression in Vibrio cholerae.

    Science.gov (United States)

    Wurm, Philipp; Tutz, Sarah; Mutsam, Beatrice; Vorkapic, Dina; Heyne, Barbara; Grabner, Claudia; Kleewein, Katharina; Halscheidt, Anja; Schild, Stefan; Reidl, Joachim

    2017-04-01

    Vibrio cholerae can colonize the gastrointestinal track of humans and cause the disease cholera. During colonization, the alternative sigma factor, RpoS, controls a process known as "mucosal escape response," defining a specific spatial and temporal response and effecting chemotaxis and motility. In this report, the expression and proteolytic control of RpoS in V. cholerae was characterized. To date, aspects of proteolysis control, the involved components, and proteolysis regulation have not been addressed for RpoS in V. cholerae. Similar to Escherichia coli, we find that the RpoS protein is subjected to regulated intracellular proteolysis, which is mediated by homologues of the proteolysis-targeting factor RssB and the protease complex ClpXP. As demonstrated, RpoS expression transiently peaks after cells are shifted from rich to minimal growth medium. This peak level is dependent on (p)ppGpp-activated rpoS transcription and controlled RpoS proteolysis. The RpoS peak level also correlates with induction of a chemotaxis gene, encoding a methyl-accepting chemotaxis protein, earlier identified to belong to the mucosal escape response pathway. These results suggest that the RpoS expression peak is linked to (p)ppGpp alarmone increase, leading to enhanced motility and chemotaxis, and possibly contributing to the mucosal escape response. Copyright © 2017 Elsevier GmbH. All rights reserved.

  18. Waste management from reprocessing: a stringent regulatory requirements for high quality conditioned residues

    International Nuclear Information System (INIS)

    Bordier, J. C.; Greneche, D.; Devezeaux, J. G.; Dalcorso, J.

    2000-01-01

    Nuclear waste production and management in France is governed by safety requirements imposed to all operators. French nuclear safety relies on two basic principles: · Responsibility of the nuclear operator, which expands to waste generated, · Safety basic objectives issued by national Safety Authority. For a long time the regulatory framework for waste production and management has been satisfactorily applied and has benefited to each actor of the process. LLW/MLW and HLW nuclear waste are currently conditioned in safe matrices or packages either likely to be disposed in surface repositories or designed with the intention to be disposed underground according to their radioactive content. France is looking into the case of VLLW and has already carried out a design for future disposal, the design being in the pipe. Other types of waste (i. e. radium bearing waste, graphite, and tritium content waste) are also considered in the whole framework of French waste management. (author)

  19. A stringently controlled expression system for analysing lateral gene transfer between bacteria.

    Science.gov (United States)

    Jaenecke, S; de Lorenzo, V; Timmis, K N; Díaz, E

    1996-07-01

    The lateral transfer of genetic information among microorganisms is a major force driving the outstanding adaptability of microbial communities to environmental changes. Until now little information has been obtained on gene transfer in natural ecosystems. We present here a genetic circuit for detecting and quantifying horizontal gene transfer from a defined donor microorganism to recipient organisms in the absence of selection for a recipient-specific phenotype. The system consists of an engineered lacZ (encoding beta-galactosidase) reporter gene whose expression is controlled by a synthetic regulatory element based on a fusion between the Pr promoter-operator from lambda bacteriophage and the 5' non-coding leader region of the inp gene encoding the IS 10 transposase function. Expression of this reporter cassette in the recombinant microorganism is completely shut down by two chromosomally encoded trans-acting repressors working at the level of transcription (the Cl-EK117 protein from the lambda phage), and at the level of translation (the antisense RNA-OUT of the IS 10 element). When the reporter element is transferred to a different host by any mechanism, it escapes repression and becomes expressed. The system was validated with Pseudo-monas putida, and conjugational transfer frequencies of the reporter element as low as 10(-6) were detected. The modular design and broad host range of the genetic circuit, in combination with biomarkers which permit real-time in situ detection, will facilitate the monitor-ing of gene flow in a non-disruptive manner within the environment.

  20. A mini-IRES sequence for stringent selection of high producers

    Indian Academy of Sciences (India)

    Internal Ribosome Entry Site (IRES) sequences have been widely used to link the expression of two independent proteins on the same mRNA transcript. Genes encoding fluorescent proteins or drug-resistance enzymes are usually placed downstream of IRES, serving as expression indicators or selection markers.

  1. Stringent upper limit of CH4 on Mars based on SOFIA/EXES observations

    Science.gov (United States)

    Aoki, S.; Richter, M. J.; DeWitt, C.; Boogert, A.; Encrenaz, T.; Sagawa, H.; Nakagawa, H.; Vandaele, A. C.; Giuranna, M.; Greathouse, T. K.; Fouchet, T.; Geminale, A.; Sindoni, G.; McKelvey, M.; Case, M.; Kasaba, Y.

    2018-03-01

    Discovery of CH4 in the Martian atmosphere has led to much discussion since it could be a signature of biological and/or geological activities on Mars. However, the presence of CH4 and its temporal and spatial variations are still under discussion because of the large uncertainties embedded in the previous observations. We performed sensitive measurements of Martian CH4 by using the Echelon-Cross-Echelle Spectrograph (EXES) onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA) on 16 March 2016, which corresponds to summer (Ls = 123.2∘) in the northern hemisphere on Mars. The high altitude of SOFIA ( 13.7 km) enables us to significantly reduce the effects of terrestrial atmosphere. Thanks to this, SOFIA/EXES improves our chances of detecting Martian CH4 lines because it reduces the impact of telluric CH4 on Martian CH4, and allows us to use CH4 lines in the 7.5 μm band which has less contamination. However, our results show no unambiguous detection of Martian CH4. The Martian disk was spatially resolved into 3 × 3 areas, and the upper limits on the CH4 volume mixing ratio range from 1 to 9 ppb across the Martian atmosphere, which is significantly less than detections in several other studies. These results emphasize that release of CH4 on Mars is sporadic and/or localized if the process is present.

  2. Stringent Expression Control of Pathogenic R-body Production in Legume Symbiont Azorhizobium caulinodans

    Directory of Open Access Journals (Sweden)

    Jun-ichi Matsuoka

    2017-07-01

    Full Text Available R bodies are insoluble large polymers consisting of small proteins encoded by reb genes and are coiled into cylindrical structures in bacterial cells. They were first discovered in Caedibacter species, which are obligate endosymbionts of paramecia. Caedibacter confers a killer trait on the host paramecia. R-body-producing symbionts are released from their host paramecia and kill symbiont-free paramecia after ingestion. The roles of R bodies have not been explained in bacteria other than Caedibacter. Azorhizobium caulinodans ORS571, a microsymbiont of the legume Sesbania rostrata, carries a reb operon containing four reb genes that are regulated by the repressor PraR. Herein, deletion of the praR gene resulted in R-body formation and death of host plant cells. The rebR gene in the reb operon encodes an activator. Three PraR binding sites and a RebR binding site are present in the promoter region of the reb operon. Expression analyses using strains with mutations within the PraR binding site and/or the RebR binding site revealed that PraR and RebR directly control the expression of the reb operon and that PraR dominantly represses reb expression. Furthermore, we found that the reb operon is highly expressed at low temperatures and that 2-oxoglutarate induces the expression of the reb operon by inhibiting PraR binding to the reb promoter. We conclude that R bodies are toxic not only in paramecium symbiosis but also in relationships between other bacteria and eukaryotic cells and that R-body formation is controlled by environmental factors.

  3. Stringent or nonstringent complete remission and prognosis in acute myeloid leukemia

    DEFF Research Database (Denmark)

    Øvlisen, Andreas K; Oest, Anders; Bendtsen, Mette D

    2018-01-01

    transfusion dependency and were suggested to be of prognostic value. In the present report, we evaluated the prognostic impact of achieving sCR and non-sCR in the Danish National Acute Leukaemia Registry, including 769 patients registered with classical CR (ie, bone marrow...

  4. A fractal image analysis methodology for heat damage inspection in carbon fiber reinforced composites

    Science.gov (United States)

    Haridas, Aswin; Crivoi, Alexandru; Prabhathan, P.; Chan, Kelvin; Murukeshan, V. M.

    2017-06-01

    The use of carbon fiber-reinforced polymer (CFRP) composite materials in the aerospace industry have far improved the load carrying properties and the design flexibility of aircraft structures. A high strength to weight ratio, low thermal conductivity, and a low thermal expansion coefficient gives it an edge for applications demanding stringent loading conditions. Specifically, this paper focuses on the behavior of CFRP composites under stringent thermal loads. The properties of composites are largely affected by external thermal loads, especially when the loads are beyond the glass temperature, Tg, of the composite. Beyond this, the composites are subject to prominent changes in mechanical and thermal properties which may further lead to material decomposition. Furthermore, thermal damage formation being chaotic, a strict dimension cannot be associated with the formed damage. In this context, this paper focuses on comparing multiple speckle image analysis algorithms to effectively characterize the formed thermal damages on the CFRP specimen. This would provide us with a fast method for quantifying the extent of heat damage in carbon composites, thus reducing the required time for inspection. The image analysis methods used for the comparison include fractal dimensional analysis of the formed speckle pattern and analysis of number and size of various connecting elements in the binary image.

  5. Improved interpretation of stroke trial results using empirical Barthel item weights.

    NARCIS (Netherlands)

    Hartingsveld, F. van; Lucas, C.; Kwakkel, G.; Lindeboom, R.

    2006-01-01

    BACKGROUND AND PURPOSE: Attempts have been made to provide guidelines for interpreting Barthel scores. We used a Rasch analysis to improve the measurement properties and clinical interpretability of the Barthel index score. METHODS: A specific extension of Rasch model was used to identify items that

  6. Improved interpretation of stroke trial results using empirical Barthel item weights

    NARCIS (Netherlands)

    van Hartingsveld, Frank; Lucas, Cees; Kwakkel, Gert; Lindeboom, Robert

    2006-01-01

    Attempts have been made to provide guidelines for interpreting Barthel scores. We used a Rasch analysis to improve the measurement properties and clinical interpretability of the Barthel index score. A specific extension of Rasch model was used to identify items that preclude the summation of items

  7. The psychometric properties of the "Reading the Mind in the Eyes" Test: an item response theory (IRT) analysis.

    Science.gov (United States)

    Preti, Antonio; Vellante, Marcello; Petretto, Donatella R

    2017-05-01

    The "Reading the Mind in the Eyes" Test (hereafter: Eyes Test) is considered an advanced task of the Theory of Mind aimed at assessing the performance of the participant in perspective-takingthat is, the ability to sense or understand other people's cognitive and emotional states. In this study, the item response theory analysis was applied to the adult version of the Eyes Test. The Italian version of the Eyes Test was administered to 200 undergraduate students of both genders (males = 46%). Modified parallel analysis (MPA) was used to test unidimensionality. Marginal maximum likelihood estimation was used to fit the 1-, 2-, and 3-parameter logistic (PL) model to the data. Differential Item Functioning (DIF) due to gender was explored with five independent methods. MPA provided evidence in favour of unidimensionality. The Rasch model (1-PL) was superior to the other two models in explaining participants' responses to the Eyes Test. There was no robust evidence of gender-related DIF in the Eyes Test, although some differences may exist for some items as a reflection of real differences by group. The study results support a one-factor model of the Eyes Test. Performance on the Eyes Test is defined by the participant's ability in perspective-taking. Researchers should cease using arbitrarily selected subscores in assessing the performance of participants to the Eyes Test. Lack of gender-related DIF favours the use of the Eyes Test in the investigation of gender differences concerning empathy and social cognition.

  8. Global trade in ornamental fish from an Australian perspective: the case for revised import risk analysis and management strategies.

    Science.gov (United States)

    Whittington, R J; Chong, R

    2007-09-14

    Over 1 billion ornamental fish comprising more than 4000 freshwater and 1400 marine species are traded internationally each year, with 8-10 million imported into Australia alone. Compared to other commodities, the pathogens and disease translocation risks associated with this pattern of trade have been poorly documented. The aim of this study was to conduct an appraisal of the effectiveness of risk analysis and quarantine controls as they are applied according to the Sanitary and Phytosanitary (SPS) agreement in Australia. Ornamental fish originate from about 100 countries and hazards are mostly unknown; since 2000 there have been 16-fold fewer scientific publications on ornamental fish disease compared to farmed fish disease, and 470 fewer compared to disease in terrestrial species (cattle). The import quarantine policies of a range of countries were reviewed and classified as stringent or non-stringent based on the levels of pre-border and border controls. Australia has a stringent policy which includes pre-border health certification and a mandatory quarantine period at border of 1-3 weeks in registered quarantine premises supervised by government quarantine staff. Despite these measures there have been many disease incursions as well as establishment of significant exotic viral, bacterial, fungal, protozoal and metazoan pathogens from ornamental fish in farmed native Australian fish and free-living introduced species. Recent examples include Megalocytivirus and Aeromonas salmonicida atypical strain. In 2006, there were 22 species of alien ornamental fish with established breeding populations in waterways in Australia and freshwater plants and molluscs have also been introduced, proving a direct transmission pathway for establishment of pathogens in native fish species. Australia's stringent quarantine policies for imported ornamental fish are based on import risk analysis under the SPS agreement but have not provided an acceptable level of protection (ALOP

  9. Safety of drinking water supplies to suburban Paris: analysis and control of radioactivity at Choisy-le-Roi

    International Nuclear Information System (INIS)

    Rapinat, M.; Philipot, J.M.; Cadet, J.L.

    1990-01-01

    The Syndicat des Eaux d'Ile de France and the Compagnie des Eaux have undertaken several stringent actions, to analyse and control radioactivity at Cholsy-le-Roi, 150 KM downstream from Nogent/s/Seine:- founding in 1985 a new laboratory branch for radioactivity measurement. - adding new elements to the existing alarm network (automatic analysis of the raw water quality). - studies for the treatability of radioelements. - using protected resources (ground water). -set up of a second treated water feeder between the river Seine and the river Marne areas. Others projects are under study, such as the creation of a raw water reservoir and increasing the capacity of treated water stockage. (author)

  10. Rasche und konsistente Senkung des Frakturrisikos unter Risedronat

    Directory of Open Access Journals (Sweden)

    Dobnig H

    2002-01-01

    Full Text Available Die bisherige Sichtweise der Osteoporose, auch unter Ärzten, war vielfach von dem Bild geprägt, daß diese nur langsam fortschreitet und eine Behandlung erst nach Jahren Wirkung zeigt. Dies kann heute eindrucksvoll durch "harte Daten" widerlegt werden. Neue Erkenntnisse zeigen nämlich, daß die manifeste Osteoporose eine äußerst dynamische Erkrankung sein kann, wobei das Auftreten der ersten Wirbelkörperfraktur einen dramatischen Wendepunkt in der weiteren Osteoporoseentwicklung darstellt: Nach einem solchen Ereignis steigt das zukünftige Frakturrisiko drastisch an, denn 20 % dieser Patienten erleiden innerhalb des darauffolgenden Jahres bereits die nächste Wirbelkörperfraktur.

  11. Modifying the Medical Research Council grading system through Rasch analyses

    NARCIS (Netherlands)

    Vanhoutte, Els Karla; Faber, Catharina Gerritdina; van Nes, Sonja Ingrid; Jacobs, Bart Casper; van Doorn, Pieter Antoon; van Koningsveld, Rinske; Cornblath, David Reid; van der Kooi, Anneke Jelly; Cats, Elisabeth Aviva; van den Berg, Leonard Hendrik; Notermans, Nicolette Claudia; van der Pol, Willem Lodewijk; Hermans, Mieke Catharina Elisabeth; van der Beek, Nadine Anna Maria Elisabeth; Gorson, Kenneth Craig; Eurelings, Marijke; Engelsman, Jeroen; Boot, Hendrik; Meijer, Ronaldus Jacobus; Lauria, Giuseppe; Tennant, Alan; Merkies, Ingemar Sergio José; Barreira, A. A.; Bennett, D.; van den Bergh, P. Y. K.; Bril, V.; Devigili, G.; Hadden, R. D.; Hahn, A. F.; Hartung, H.-P.; Hughes, R. A. C.; Illa, I.; Katzberg, H.; Léger, J.-M.; Lewis, R. A.; Lunn, M. P. T.; Nascimento, O. J. M.; Nobile-Orazio, E.; Padua, L.; Pouget, J.; Reilly, M. M.; van Schaik, I.; Smith, B.; de Visser, M.; Walk, D.

    2012-01-01

    The Medical Research Council grading system has served through decades for the evaluation of muscle strength and has been recognized as a cardinal feature of daily neurological, rehabilitation and general medicine examination of patients, despite being respectfully criticized due to the unequal

  12. Modifying the Medical Research Council grading system through Rasch analyses

    NARCIS (Netherlands)

    E.K. Vanhoutte (Els); C.G. Faber (Carin); S.I. van Nes (Sonja); B.C. Jacobs (Bart); P.A. van Doorn (Pieter); R. van Koningsveld (Rinske); D.R. Cornblath (David); A.J. Kooj (Anneke); E.A. Cats (Elisabeth); L.H. van den Berg (Leonard); N.C. Notermans (Nicolette); W.L. van der Pol (Ludo); M.C.E. Hermans; N.A.M.E. van der Beek (Nadine); K.C. Gorson (Kenneth); M. Eurelings (Marijke); L. Engelsman (Lyda); H. Boot (Hendrik); R.J. Meijer (Ron); G. Lauria (Giuseppe); C. Tennant (Christopher); I.S.J. Merkies (Ingemar)

    2012-01-01

    textabstractThe Medical Research Council grading system has served through decades for the evaluation of muscle strength and has been recognized as a cardinal feature of daily neurological, rehabilitation and general medicine examination of patients, despite being respectfully criticized due to the

  13. Tree-Based Global Model Tests for Polytomous Rasch Models

    Science.gov (United States)

    Komboz, Basil; Strobl, Carolin; Zeileis, Achim

    2018-01-01

    Psychometric measurement models are only valid if measurement invariance holds between test takers of different groups. Global model tests, such as the well-established likelihood ratio (LR) test, are sensitive to violations of measurement invariance, such as differential item functioning and differential step functioning. However, these…

  14. Evidence-Based Clinical Significance in Health Care: Toward an Inferential Analysis of Clinical Relevance

    Directory of Open Access Journals (Sweden)

    Mahsa Dousti

    2011-09-01

    Full Text Available Evidence-based dental practice requires the developmment and evaluation of protocols that en-sure translational effectiveness: that is, the efficient incorporation of the best available efficacy and effec-tiveness findings in specific clinical dentistry settings and environments. Evidence-based dentistry predi-cates the synthesis of research for obtaining the best available evidence in a validated, stringent, systematic and unbiased fashion. Research synthesis is now established as a science in its own right, precisely because it adheres to the scientific process that is driven by a research question and a hypothesis, follows through clearly defined methodology and design, yielding quantifiable data that are analyzed statistically, and from which stringent statistical inferences are drawn. The conclusions from the protocol of research synthesis define the best available evidence, which is used in the process of evidence-based revision of clinical practice guidelines. One important hurdle of the process of applying research synthesis in evidence-based dentistry lies in the fact that the statistical inferences produced by research must be translated into clinical relevance. Here, we present a model to circumvent this limitation by means of text analysis/mining protocols, which could lead the path toward a novel, valid and reliable ap-proach for the inferential analysis of clinical relevance.

  15. Vibration analysis for trending ageing in rotating machinery

    International Nuclear Information System (INIS)

    Sinha, S.K.; Rama Rao, A.

    2006-01-01

    The need for condition monitoring system for important equipment and machinery is a growing requirement in every industry and more so in the nuclear power plants because of stringent safety requirements. This is largely because of the inherent benefit of being able to promote predictive maintenance practice rather than uneconomical preventive maintenance practice in the plant. Forerunner among the condition monitoring parameter is vibration signatures measured on a rotating machine. It is known that every moving element in a rotating machine generates vibration signal that is uniquely its own. Detection of such signals and monitoring the changing conditions in a machine through vibration analysis is a technique involving the knowledge of engineering art and the mathematical theory. This blend of sound engineering judgement and vibration data interpretation skill is in fact the basis of vibration diagnostic techniques. (author)

  16. Assessing Computational Steps for CLIP-Seq Data Analysis

    Directory of Open Access Journals (Sweden)

    Qi Liu

    2015-01-01

    Full Text Available RNA-binding protein (RBP is a key player in regulating gene expression at the posttranscriptional level. CLIP-Seq, with the ability to provide a genome-wide map of protein-RNA interactions, has been increasingly used to decipher RBP-mediated posttranscriptional regulation. Generating highly reliable binding sites from CLIP-Seq requires not only stringent library preparation but also considerable computational efforts. Here we presented a first systematic evaluation of major computational steps for identifying RBP binding sites from CLIP-Seq data, including preprocessing, the choice of control samples, peak normalization, and motif discovery. We found that avoiding PCR amplification artifacts, normalizing to input RNA or mRNAseq, and defining the background model from control samples can reduce the bias introduced by RNA abundance and improve the quality of detected binding sites. Our findings can serve as a general guideline for CLIP experiments design and the comprehensive analysis of CLIP-Seq data.

  17. Spatial Autocorrelation Analysis of Chinese Inter-Provincial Industrial Chemical Oxygen Demand Discharge

    Directory of Open Access Journals (Sweden)

    Yibo Liu

    2012-05-01

    Full Text Available A spatial autocorrelation analysis method is adopted to process the spatial dynamic change of industrial Chemical Oxygen Demand (COD discharge in China over the past 15 years. Studies show that amount and intensity of industrial COD discharges are on a decrease, and the tendency is more remarkable for discharge intensity. There are large differences between inter-provincial discharge amount and intensity, and with different spatial differentiation features. Global spatial autocorrelation analysis reveals that Global Moran’s I of discharge amount and intensity is on the decrease. In space, there is an evolution from an agglomeration pattern to a discretization pattern. Local spatial autocorrelation analysis shows that the agglomeration area of industrial COD discharge amount and intensity varies greatly in space with time. Stringent environmental regulations and increased funding for environmental protections are the crucial factors to cut down industrial COD discharge amount and intensity.

  18. Spatial autocorrelation analysis of Chinese inter-provincial industrial chemical oxygen demand discharge.

    Science.gov (United States)

    Zhao, Xiaofeng; Huang, Xianjin; Liu, Yibo

    2012-06-01

    A spatial autocorrelation analysis method is adopted to process the spatial dynamic change of industrial Chemical Oxygen Demand (COD) discharge in China over the past 15 years. Studies show that amount and intensity of industrial COD discharges are on a decrease, and the tendency is more remarkable for discharge intensity. There are large differences between inter-provincial discharge amount and intensity, and with different spatial differentiation features. Global spatial autocorrelation analysis reveals that Global Moran's I of discharge amount and intensity is on the decrease. In space, there is an evolution from an agglomeration pattern to a discretization pattern. Local spatial autocorrelation analysis shows that the agglomeration area of industrial COD discharge amount and intensity varies greatly in space with time. Stringent environmental regulations and increased funding for environmental protections are the crucial factors to cut down industrial COD discharge amount and intensity.

  19. ANALYSIS OF THE LICENSED TOURIST GUIDES’ EVOLUTION OF ROMANIA AND CRITICAL ISSUES AFFECTING THEIR ACTIVITY

    Directory of Open Access Journals (Sweden)

    Corina TĂTAR

    2017-10-01

    Full Text Available The study refers to the licensed tourist guides of Romania during 1998-2016, namely their numerical evolution during this time series as well as an analysis of their numerical evolution by different types of tourist guides, be they national, local or specialized. The statistical analysis showed an increment from 24 tourist guides in the year 1998 to 4,335 licensed tour guides in 2016. The analysis is supplemented by current issues and shortcomings affecting the tourist guiding activity of Romania, as revealed by the tourist guides present at the annual tourist guides’ national conferences, various stringent problems raised and debated within these encounters and highlighted by this study as well as proposals for a better functioning for this segment of tourism entrepreneurs.

  20. Reducing work disability in Ankylosing Spondylitis – development of a work instability scale for AS

    Directory of Open Access Journals (Sweden)

    Helliwell Philip

    2009-06-01

    Full Text Available Abstract Background The Work Instability Scale for Rheumatoid Arthritis (RA-WIS is established and is used by physicians to identify patients at risk of job loss for rapid intervention. The study objective was to explore the concept of Work Instability (a mismatch between an individual's abilities and job demands in Ankylosing Spondylitis (AS and develop a Work Instability Scale specific to this population. Methods New items generated from qualitative interviews were combined with items from the RA-WIS to form a draft AS-WIS. Rasch analysis was used to examine the scaling properties of the AS-WIS using data generated through a postal survey. The scale was validated against a gold standard of expert assessment, a test-retest survey examined reliability. Results Fifty-seven participants who were in work returned the postal survey. Of the original 55 items 38 were shown to fit the Rasch model (χ2 37.5; df 38; p 0.494 and free of bias for gender and disease duration. Following analysis for discrimination against the gold standard assessments 20 items remained with good fit to the model (χ2 24.8; df 20; p 0.21. Test-retest reliability was 0.94. Conclusion The AS-WIS is a self-administered scale which meets the stringent requirements of modern measurement. Used as a screening tool it can identify those experiencing a mismatch at work who are at risk of job retention problems and work disability. Work instability is emerging as an important indication for the use of biologics, thus the AS-WIS has the potential to become an important outcome measure.

  1. A comparative proteome analysis of Escherichia coli DeltarelA mutant cells

    Directory of Open Access Journals (Sweden)

    Sónia Carneiro

    2016-10-01

    Full Text Available The bacterial RelA-dependent stringent response exerts a strong influence over a wide variety of processes. In this work, the impact of the relA gene mutation in E. coli cells was evaluated by a quantitative proteomics analysis, employing stable-isotope labelling and high resolution mass spectrometry. Chemostat cultures of E. coli W3110 and ∆relA mutant strains were performed at two dilution rates (0.1 and 0.2 h-1 to assess the influence of the relA gene mutation in steady-state protein levels. A total of 121 proteins showed significant alterations in their abundance when comparing the proteome of mutant to wild-type cells. The relA gene mutation induced changes on key cellular processes, including the amino acids and nucleotide biosynthesis, the lipid metabolism, transport activities, transcription and translation processes and responses to stress. Furthermore, some of those changes were more pronounced under specific growth conditions, as the most significant differences in protein ratios were observed at one of the dilution rates. An effect of the relA gene mutation in the acetate overflow was also observed, which confers interesting characteristics to this mutant strain that could be useful in the production of recombinant proteins. Overall, these results provide a valuable insight into the E. coli stringent response under defined steady-state conditions, suggesting that this stress response might influence multiple metabolic processes like the acetate overflow or the catabolite repression.

  2. Economic analysis of the profitability of energy-saving architectural measures for the achievement of the EPB-standard

    International Nuclear Information System (INIS)

    Audenaert, A.; De Boeck, L.; Roelants, K.

    2010-01-01

    Energy efficiency in buildings has become a key goal of any energy policy. Europe relies on the Energy Performance of Buildings Directive (EPBD), which has been converted by Flanders into the 'Energy Performance and Interior Climate' (EPB). Taking into account this Flemish EPB-standard (in terms of maximum U-values, E-level and K-value), this study seeks the economically most profitable combination of insulation - facade, roof, floor and glazing - for the Flemish citizen. For this purpose, a scenario-analysis is conducted using the EPB-software Flanders and a self-designed Excel file. Based on some important profitability criteria, the most profitable combination is determined for three representative types of dwellings studied. The scenario-analysis generates some well-founded guidelines for the Flemish citizen when building a house. It shows that in order to ensure the maximum profitability from investment in insulation, the key factor for the semi-detached dwelling is the insulation of roof and floor, whereas for a detached dwelling the key factor is the insulation of facade and floor. As a subsidiary consideration, the study also indicates that the U-values resulting from the more stringent E-level are still not sufficiently stringent because the U-values obtained for the most profitable combination are far below their maximum value. The same consideration applies in the case of the K-value.

  3. Dimensionality of the Knee Numeric-Entity Evaluation Score (KNEES-ACL)

    DEFF Research Database (Denmark)

    Comins, J D; Krogsgaard, M R; Kreiner, Svend

    2013-01-01

    The benefit of anterior cruciate ligament (ACL) reconstruction has been questioned based on patient-reported outcome measures (PROMs). Valid interpretation of such results requires confirmation of the psychometric properties of the PROM. Rasch analysis is the gold standard for validation of PROMs......, yet PROMs used for ACL reconstruction have not been validated using Rasch analysis. We used Rasch analysis to investigate the psychometric properties of the Knee Numeric-Entity Evaluation Score (KNEES-ACL), a newly developed PROM for patients treated for ACL deficiency. Two-hundred forty-two patients...

  4. AN ANALYSIS OF SOCIAL INCLUSION IN EU

    Directory of Open Access Journals (Sweden)

    HARALAMBIE GEORGE ALIN

    2017-08-01

    Full Text Available Social inclusion, a dynamic process of stringent topicality, manifested in the community space, is constituted in a subject with multiple reverberations on contemporary society. From this perspective, the growing interest of the Member States in social inclusion is due to the widening of existing inequalities in terms of people's living standards due to the deterioration of economic well-being. A growing number of studies on social cohesion at the level of the countries of the European Union tried to identify the similarities and disparities between Member States in the process of social inclusion. The paper evaluated and compared the existing disparities between the 28 EU countries, based on a set of social indicators that provide an insight into social inclusion. The methodology used implied a cluster analysis based on the method of k-means, which allowed me to form a grouping of Member States based on indicators of social inclusion. The results of the analysis reveal significant differences between the countries of the European Union regarding social inclusion due to factors of a political, economic and social nature. Understanding the mechanism of manifestation and correction of the level of social inclusion can provide, in this sense, explanations and solutions in capitalizing the economic potential by developing specific policies to the existing social imbalances.

  5. Examining the Psychometric Quality of Multiple-Choice Assessment Items using Mokken Scale Analysis.

    Science.gov (United States)

    Wind, Stefanie A

    The concept of invariant measurement is typically associated with Rasch measurement theory (Engelhard, 2013). Concerned with the appropriateness of the parametric transformation upon which the Rasch model is based, Mokken (1971) proposed a nonparametric procedure for evaluating the quality of social science measurement that is theoretically and empirically related to the Rasch model. Mokken's nonparametric procedure can be used to evaluate the quality of dichotomous and polytomous items in terms of the requirements for invariant measurement. Despite these potential benefits, the use of Mokken scaling to examine the properties of multiple-choice (MC) items in education has not yet been fully explored. A nonparametric approach to evaluating MC items is promising in that this approach facilitates the evaluation of assessments in terms of invariant measurement without imposing potentially inappropriate transformations. Using Rasch-based indices of measurement quality as a frame of reference, data from an eighth-grade physical science assessment are used to illustrate and explore Mokken-based techniques for evaluating the quality of MC items. Implications for research and practice are discussed.

  6. Development of a Short Version of MSQOL-54 Using Factor Analysis and Item Response Theory.

    Directory of Open Access Journals (Sweden)

    Rosalba Rosato

    Full Text Available The Multiple Sclerosis Quality of Life-54 (MSQOL-54, 52 items grouped in 12 subscales plus two single items is the most used MS specific health related quality of life inventory.To develop a shortened version of the MSQOL-54.MSQOL-54 dimensionality and metric properties were investigated by confirmatory factor analysis (CFA and Rasch modelling (Partial Credit Model, PCM on MSQOL-54s completed by 473 MS patients. Their mean age was 41 years, 65% were women, and median Expanded Disability Status Scale (EDSS score was 2.0 (range 0-9.5. Differential item functioning (DIF was evaluated for gender, age and EDSS. Dimensionality of the resulting short version was assessed by exploratory factor analysis (EFA and CFA. Cognitive debriefing of the short instrument (vs. the original was then performed on 12 MS patients.CFA of MSQOL-54 subscales showed that the data fitted the overall model well. Two subscales (Role Limitations--Physical, Role Limitations--Emotional did not fit the PCM, and were removed; two other subscales (Health Perceptions, Social Function did not fit the model, but were retained as single items. Sexual Satisfaction (single-item subscale was also removed. The resulting MSQOL-29 consisted of 25 items grouped in 7 subscales, plus 4 single items. PCM fit statistics were within the acceptability range for all MSQOL-29 items except one which had significant DIF by age. EFA and CFA indicated adequate fit to the original two-factor (Physical and Mental Health Composites hypothesis. Cognitive debriefing confirmed that MSQOL-29 was acceptable and had lost no key items.The proposed MSQOL-29 is 50% shorter than MSQOL-54, yet preserves key quality of life dimensions. Prospective validation on a large, independent MS patient sample is ongoing.

  7. Optimal climate policy is a utopia. From quantitative to qualitative cost-benefit analysis

    International Nuclear Information System (INIS)

    Van den Bergh, Jeroen C.J.M.

    2004-01-01

    The dominance of quantitative cost-benefit analysis (CBA) and optimality concepts in the economic analysis of climate policy is criticised. Among others, it is argued to be based in a misplaced interpretation of policy for a complex climate-economy system as being analogous to individual inter-temporal welfare optimisation. The transfer of quantitative CBA and optimality concepts reflects an overly ambitious approach that does more harm than good. An alternative approach is to focus the attention on extreme events, structural change and complexity. It is argued that a qualitative rather than a quantitative CBA that takes account of these aspects can support the adoption of a minimax regret approach or precautionary principle in climate policy. This means: implement stringent GHG reduction policies as soon as possible

  8. Impact of sample size on principal component analysis ordination of an environmental data set: effects on eigenstructure

    Directory of Open Access Journals (Sweden)

    Shaukat S. Shahid

    2016-06-01

    Full Text Available In this study, we used bootstrap simulation of a real data set to investigate the impact of sample size (N = 20, 30, 40 and 50 on the eigenvalues and eigenvectors resulting from principal component analysis (PCA. For each sample size, 100 bootstrap samples were drawn from environmental data matrix pertaining to water quality variables (p = 22 of a small data set comprising of 55 samples (stations from where water samples were collected. Because in ecology and environmental sciences the data sets are invariably small owing to high cost of collection and analysis of samples, we restricted our study to relatively small sample sizes. We focused attention on comparison of first 6 eigenvectors and first 10 eigenvalues. Data sets were compared using agglomerative cluster analysis using Ward’s method that does not require any stringent distributional assumptions.

  9. Acanthamoeba castellanii contains a ribosomal RNA enhancer binding protein which stimulates TIF-IB binding and transcription under stringent conditions.

    Science.gov (United States)

    Yang, Q; Radebaugh, C A; Kubaska, W; Geiss, G K; Paule, M R

    1995-01-01

    The intergenic spacer (IGS) of Acanthamoeba castellanii rRNA genes contains repeated elements which are weak enhancers for transcription by RNA polymerase I. A protein, EBF, was identified and partially purified which binds to the enhancers and to several other sequences within the IGS, but not to other DNA fragments, including the rRNA core promoter. No consensus binding sequence could be discerned in these fragments and bound factor is in rapid equilibrium with unbound. EBF has functional characteristics similar to vertebrate upstream binding factors (UBF). Not only does it bind to the enhancer and other IGS elements, but it also stimulates binding of TIF-IB, the fundamental transcription initiation factor, to the core promoter and stimulates transcription from the promoter. Attempts to identify polypeptides with epitopes similar to rat or Xenopus laevis UBF suggest that structurally the protein from A.castellanii is not closely related to vertebrate UBF. Images PMID:7501455

  10. Synthesis of well-defined alkyne terminated poly(N-vinyl caprolactam) with stringent control over the LCST by RAFT.

    Science.gov (United States)

    Góis, Joana R; Costa, João R C; Popov, Anatoliy V; Serra, Arménio C; Coelho, Jorge F J

    The reversible addition-fragmentation chain transfer (RAFT) of N -vinyl caprolactam (NVCL) using two new xanthates with alkyne functionalities is reported. The kinetic data obtained for polymerization of this non-activated monomer using a protected alkyne-terminated RAFT agent (PAT-X 1 ) revealed a linear increase of the polymer molecular weight with the monomer conversion as well as low dispersity ( Đ ) during the entire course of the polymerization. The system reported here allowed us to enhance the final conversion, diminish Đ and reduce the polymerization temperature compared to the typical values reported in the scarce literature available for the RAFT polymerization of NVCL. The resulting PNVCL was fully characterized using 1 H nuclear magnetic resonance ( 1 H NMR), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), Fourier-transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) techniques. The temperature-responsive features of PNVCL in aqueous solutions were fully investigated under different conditions using turbidimetry. The presented strategy allows the synthesis of well-defined PNVCL with sharp and reversible phase transition temperatures around 37 °C. By manipulating the polymer molecular weight, or the solution properties, it is possible to tune the PNVCL phase transition. As a proof-of concept, the alkyne functionalized PNVCL was used to afford new linear block copolymers, by reacting with an azide-terminated poly(ethylene glycol) (N 3 -PEG) through the copper catalyzed azide-alkyne [3+2] dipolar cycloaddition (CuAAC) reaction. The results presented establish a robust system to afford the synthesis of PNCVL with fine tuned characteristics that will enable more efficient exploration of the remarkable potential of this polymer in biomedical applications.

  11. Legal status and source of offenders' firearms in states with the least stringent criteria for gun ownership.

    Science.gov (United States)

    Vittes, Katherine A; Vernick, Jon S; Webster, Daniel W

    2013-02-01

    Gun possession by high-risk individuals presents a serious threat to public safety. U.S. federal law establishes minimum criteria for legal purchase and possession of firearms; many states have laws disqualifying additional categories for illegal possession. We used data from a national survey of state prison inmates to calculate: 1) the proportion of offenders, incarcerated for crimes committed with firearms in 13 states with the least restrictive firearm purchase and possession laws, who would have been prohibited if their states had stricter gun laws; and 2) the source of gun acquisition for offenders who were and were not legally permitted to purchase and possess firearms. Nearly three of ten gun offenders (73 of 253 or 28.9%) were legal gun possessors but would have been prohibited from purchasing or possessing firearms when committing their most recent offense if their states had stricter prohibitions. Offenders who were already prohibited under current law acquired their gun from a licensed dealer, where a background check is required, five times less often than offenders who were not prohibited (3.9% vs. 19.9%; χ(2)=13.31; p≤0.001). Nearly all (96.1%) offenders who were legally prohibited, acquired their gun from a supplier not required to conduct a background check. Stricter gun ownership laws would have made firearm possession illegal for many state prison inmates who used a gun to commit a crime. Requiring all gun sales to be subject to a background check would make it more difficult for these offenders to obtain guns.

  12. Possible energy futures for Brazil and Latin America in conservative and stringent mitigation pathways up to 2050

    NARCIS (Netherlands)

    Herreras Martinez, Sara; Koberle, Alexandre; Rochedo, Pedro; Schaeffer, Roberto; Lucena, Andre; Szklo, Alexandre; Ashina, Shuichi; van Vuuren, Detlef P.|info:eu-repo/dai/nl/11522016X

    2015-01-01

    Latin America has a unique position to address climate change impacts due to its many mitigation opportunities and its growing economy. This paper applied two global and one regional integrated assessment models to assess the energy and emissions trends in Brazil and the rest of the Latin American

  13. Yeast 18 S rRNA Is Directly Involved in the Ribosomal Response to Stringent AUG Selection during Translation Initiation

    Czech Academy of Sciences Publication Activity Database

    Nemoto, N.; Singh, Ch. R.; Udagawa, T.; Wang, S.; Thorson, E.; Winter, Z.; Ohira, T.; Li, M.; Valášek, Leoš; Brown, S. J.; Asano, K.

    2010-01-01

    Roč. 285, č. 42 (2010), s. 32200-32212 ISSN 0021-9258 Institutional research plan: CEZ:AV0Z50200510 Keywords : START CODON SELECTION * SACCHAROMYCES-CEREVISIAE * IN-VIVO Subject RIV: EE - Microbiology, Virology Impact factor: 5.328, year: 2010

  14. A Psychometric Analysis of Functional Category Production in English Agrammatic Narratives

    Science.gov (United States)

    Milman, Lisa H.; Dickey, Michael Walsh; Thompson, Cynthia K.

    2009-01-01

    Hierarchical models of agrammatism propose that sentence production deficits can be accounted for in terms of clausal syntactic structure (Friedmann & Grodzinsky, 1997; Hagiwara, 1995). Such theories predict that morpho-syntactic elements associated with higher nodes in the syntactic tree (complementizers and verb inflections) will be more impaired than elements associated with lower structural positions (negation markers and aspectual verb forms). While this hypothesis has been supported by the results of several studies (Benedet, Christiansen, & Goodglass, 1998; Friedmann, 2001, 2002), it has also been challenged on several grounds (Burchert, Swoboda-Moll, & De Bleser, 2005a; Lee, 2003; Lee, Milman, & Thompson, 2005). In this paper the question of hierarchical structure was re-examined within the framework of Item Response Theory (IRT, Rasch, 1980). IRT is a probabilistic model widely used in the field of psychometrics to model behavioral constructs as numeric variables. In this study we examined production of functional categories (complementizers, verb inflections, negation markers, and aspectual verb forms) in narrative samples elicited from 18 individuals diagnosed with nonfluent aphasia and 18 matched controls. Data from the aphasic participants were entered into an IRT analysis to test 1) whether production of clausal functional categories can be represented as a variable on a numeric scale; and 2) whether production patterns were consistent with hierarchical syntactic structure. Pearson r correlation coefficients were also computed to determine whether there was a relation between functional category production and other indices of language performance. Results indicate that functional category production can be modeled as a numeric variable using IRT. Furthermore, although variability was observed across individuals, consistent patterns were evident when the data were interpreted within a probabilistic framework. Although functional category production

  15. Do emotional intelligence and previous caring experience influence student nurse performance? A comparative analysis.

    Science.gov (United States)

    Stenhouse, Rosie; Snowden, Austyn; Young, Jenny; Carver, Fiona; Carver, Hannah; Brown, Norrie

    2016-08-01

    Reports of poor nursing care have focused attention on values based selection of candidates onto nursing programmes. Values based selection lacks clarity and valid measures. Previous caring experience might lead to better care. Emotional intelligence (EI) might be associated with performance, is conceptualised and measurable. To examine the impact of 1) previous caring experience, 2) emotional intelligence 3) social connection scores on performance and retention in a cohort of first year nursing and midwifery students in Scotland. A longitudinal, quasi experimental design. Adult and mental health nursing, and midwifery programmes in a Scottish University. Adult, mental health and midwifery students (n=598) completed the Trait Emotional Intelligence Questionnaire-short form and Schutte's Emotional Intelligence Scale on entry to their programmes at a Scottish University, alongside demographic and previous caring experience data. Social connection was calculated from a subset of questions identified within the TEIQue-SF in a prior factor and Rasch analysis. Student performance was calculated as the mean mark across the year. Withdrawal data were gathered. 598 students completed baseline measures. 315 students declared previous caring experience, 277 not. An independent-samples t-test identified that those without previous caring experience scored higher on performance (57.33±11.38) than those with previous caring experience (54.87±11.19), a statistically significant difference of 2.47 (95% CI, 0.54 to 4.38), t(533)=2.52, p=.012. Emotional intelligence scores were not associated with performance. Social connection scores for those withdrawing (mean rank=249) and those remaining (mean rank=304.75) were statistically significantly different, U=15,300, z=-2.61, p$_amp_$lt;0.009. Previous caring experience led to worse performance in this cohort. Emotional intelligence was not a useful indicator of performance. Lower scores on the social connection factor were associated

  16. Accounting for standard errors of vision-specific latent trait in regression models.

    Science.gov (United States)

    Wong, Wan Ling; Li, Xiang; Li, Jialiang; Wong, Tien Yin; Cheng, Ching-Yu; Lamoureux, Ecosse L

    2014-07-11

    To demonstrate the effectiveness of Hierarchical Bayesian (HB) approach in a modeling framework for association effects that accounts for SEs of vision-specific latent traits assessed using Rasch analysis. A systematic literature review was conducted in four major ophthalmic journals to evaluate Rasch analysis performed on vision-specific instruments. The HB approach was used to synthesize the Rasch model and multiple linear regression model for the assessment of the association effects related to vision-specific latent traits. The effectiveness of this novel HB one-stage "joint-analysis" approach allows all model parameters to be estimated simultaneously and was compared with the frequently used two-stage "separate-analysis" approach in our simulation study (Rasch analysis followed by traditional statistical analyses without adjustment for SE of latent trait). Sixty-six reviewed articles performed evaluation and validation of vision-specific instruments using Rasch analysis, and 86.4% (n = 57) performed further statistical analyses on the Rasch-scaled data using traditional statistical methods; none took into consideration SEs of the estimated Rasch-scaled scores. The two models on real data differed for effect size estimations and the identification of "independent risk factors." Simulation results showed that our proposed HB one-stage "joint-analysis" approach produces greater accuracy (average of 5-fold decrease in bias) with comparable power and precision in estimation of associations when compared with the frequently used two-stage "separate-analysis" procedure despite accounting for greater uncertainty due to the latent trait. Patient-reported data, using Rasch analysis techniques, do not take into account the SE of latent trait in association analyses. The HB one-stage "joint-analysis" is a better approach, producing accurate effect size estimations and information about the independent association of exposure variables with vision-specific latent traits

  17. A Method for Investigating “Instructional Familiarity” and Discerning ...

    African Journals Online (AJOL)

    action research” design for a medical school course focusing on endocrinology. Rasch measurement model; correlation analysis. Results: The methodology presented in this article was evidenced to better discern authentic learning than traditional ...

  18. MIPAS level 2 operational analysis

    Directory of Open Access Journals (Sweden)

    P. Raspollini

    2006-01-01

    Full Text Available The MIPAS (Michelson Interferometer for Passive Atmospheric Sounding instrument has been operating on-board the ENVISAT satellite since March 2002. In the first two years, it acquired in a nearly continuous manner high resolution (0.025 cm−1 unapodized emission spectra of the Earth's atmosphere at limb in the middle infrared region. This paper describes the level 2 near real-time (NRT and off-line (OL ESA processors that have been used to derive level 2 geophysical products from the calibrated and geolocated level 1b spectra. The design of the code and the analysis methodology have been driven by the requirements for NRT processing. This paper reviews the performance of the optimized retrieval strategy that has been implemented to achieve these requirements and provides estimated error budgets for the target products: pressure, temperature, O3, H2O, CH4, HNO3, N2O and NO2, in the altitude measurement range from 6 to 68 km. From application to real MIPAS data, it was found that no change was needed in the developed code although an external algorithm was introduced to identify clouds with high opacity and to exclude affected spectra from the analysis. In addition, a number of updates were made to the set-up parameters and to auxiliary data. In particular, a new version of the MIPAS dedicated spectroscopic database was used and, in the OL analysis, the retrieval range was extended to reduce errors due to uncertainties in extrapolation of the profile outside the retrieval range and more stringent convergence criteria were implemented. A statistical analysis on the χ2 values obtained in one year of measurements shows good agreement with the a priori estimate of the forward model errors. On the basis of the first two years of MIPAS measurements the estimates of the forward model and instrument errors are in general found to be conservative with excellent performance demonstrated for frequency calibration. It is noted that the total retrieval

  19. Design and Error Analysis of a Vehicular AR System with Auto-Harmonization.

    Science.gov (United States)

    Foxlin, Eric; Calloway, Thomas; Zhang, Hongsheng

    2015-12-01

    This paper describes the design, development and testing of an AR system that was developed for aerospace and ground vehicles to meet stringent accuracy and robustness requirements. The system uses an optical see-through HMD, and thus requires extremely low latency, high tracking accuracy and precision alignment and calibration of all subsystems in order to avoid mis-registration and "swim". The paper focuses on the optical/inertial hybrid tracking system and describes novel solutions to the challenges with the optics, algorithms, synchronization, and alignment with the vehicle and HMD systems. Tracker accuracy is presented with simulation results to predict the registration accuracy. A car test is used to create a through-the-eyepiece video demonstrating well-registered augmentations of the road and nearby structures while driving. Finally, a detailed covariance analysis of AR registration error is derived.

  20. Analysis of Traffic Engineering capabilities for SDN-based Data Center Networks

    DEFF Research Database (Denmark)

    Pilimon, Artur; Kentis, Angelos Mimidis; Ruepp, Sarah Renée

    2018-01-01

    techniques focusing on their limitations. Then, it highlights the benefits of incorporating the Software Defined Networking (SDN) paradigm to address these limitations. Furthermore, it illustrates two methodologies and addresses the scalability aspect of DCN-oriented TE, network and service testing...... Center Networks (DCN), thus creating the need to evolve them. Traffic Engineering (TE) has long been the way of attacking this problem, but as with DCN, needs to evolve by encompassing new technologies and paradigms. This paper provides a comprehensive analysis of current DCN operational and TE......In the recent years more and more existing services have moved from local execution environments into the cloud. In addition, new cloud-based services are emerging, which are characterized by very stringent delay requirements. This trend puts a stress in the existing monolithic architecture of Data...

  1. Tight finite-key analysis for passive decoy-state quantum key distribution under general attacks

    Science.gov (United States)

    Zhou, Chun; Bao, Wan-Su; Li, Hong-Wei; Wang, Yang; Li, Yuan; Yin, Zhen-Qiang; Chen, Wei; Han, Zheng-Fu

    2014-05-01

    For quantum key distribution (QKD) using spontaneous parametric-down-conversion sources (SPDCSs), the passive decoy-state protocol has been proved to be efficiently close to the theoretical limit of an infinite decoy-state protocol. In this paper, we apply a tight finite-key analysis for the passive decoy-state QKD using SPDCSs. Combining the security bound based on the uncertainty principle with the passive decoy-state protocol, a concise and stringent formula for calculating the key generation rate for QKD using SPDCSs is presented. The simulation shows that the secure distance under our formula can reach up to 182 km when the number of sifted data is 1010. Our results also indicate that, under the same deviation of statistical fluctuation due to finite-size effects, the passive decoy-state QKD with SPDCSs can perform as well as the active decoy-state QKD with a weak coherent source.

  2. Experimental analysis of Nd-YAG laser cutting of sheet materials - A review

    Science.gov (United States)

    Sharma, Amit; Yadava, Vinod

    2018-01-01

    Cutting of sheet material is considered as an important process due to its relevance among products of everyday life such as aircrafts, ships, cars, furniture etc. Among various sheet cutting processes (ASCPs), laser beam cutting is one of the most capable ASCP to create complex geometries with stringent design requirements in difficult-to-cut sheet materials. Based on the recent research work in the area of sheet cutting, it is found that the Nd-YAG laser is used for cutting of sheet material in general and reflective sheet material in particular. This paper reviews the experimental analysis of Nd-YAG laser cutting process, carried out to study the influence of laser cutting parameters on the process performance index. The significance of experimental modeling and different optimization approaches employed by various researchers has also been discussed in this study.

  3. Thermal and stress analysis of the Faraday shield for the ORNL/TFTR rf antenna

    International Nuclear Information System (INIS)

    Hammonds, C.J.; Nelson, B.E.; Walls, J.C.; Hoffman, D.J.; Baity, F.W.

    1989-01-01

    The rf antenna designed and built by Oak Ridge National Laboratory (ORNL) for the Tokamak Fusion Test Reactor (TFTR) is an ion cyclotron resonance heating antenna operating in the 40- to 80-MHz frequency range with a power output of 4 MW for a 2-s pulse. The antenna was delivered to Princeton in November 1987. A review of the antenna design began in early 1988 to ensure compatibility with D-T operation of TFTR. Owing to the serious consequences of a water leak during D-T operation and to other concerns, it was concluded that the Faraday shield of the antenna should be rebuilt. In addition, because of increased heat loads and more stringent acceptance criteria, a new thermal and stress analysis of the shield was authorized. 1 ref., 8 figs., 5 tabs

  4. Genetic analysis of a type IV pili-like locus in the archaeon Methanococcus maripaludis.

    Science.gov (United States)

    Nair, Divya B; Uchida, Kaoru; Aizawa, Shin-Ichi; Jarrell, Ken F

    2014-03-01

    Methanococcus maripaludis is a stringently anaerobic archaeon with two studied surface structures, archaella and type IV pili. Previously, it was shown that three pilin genes (mmp0233 [epdA], mmp0236 [epdB] and mmp0237 [epdC]) located within an 11 gene cluster in the genome were necessary for normal piliation. This study focused on analysis of the remaining genes to determine their potential involvement in piliation. Reverse transcriptase PCR experiments demonstrated the 11 genes formed a single transcriptional unit. Deletions were made in all the non-pilin genes except mmp0231. Electron microscopy revealed that all the genes in the locus except mmp0235 and mmp0238 were essential for piliation. Complementation with a plasmid-borne wild-type copy of the deleted gene restored at least some piliation. We identified genes for an assembly ATPase and two versions of the conserved pilin platform forming protein necessary for pili assembly at a separate genetic locus.

  5. Analysis of population dosimetry data in the high level natural radiation areas, Kerala, India

    International Nuclear Information System (INIS)

    Chougaonkar, M.P.; Mayya, Y.S.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.; Eappen, K.P.; Ramachandran, T.V.; Jojo, P.J.; Predeep, P.

    2010-01-01

    In the Indian scenario, Kerala has huge monazite bearing sand deposits on the west coast thereby having high natural background radiation levels. Extensive studies on the radiation dosimetry as well as effects on the human health are therefore being carried out in the region. We have recently completed a dosimetric survey aimed for epidemiological studies using case control methodology. This study, in collaboration with two local colleges in Kollam, Kerala, was taken up to study the relationship of congenital malformations and radiation exposures, if any. The two conditions that were selected were mental retardation and cleft lip-palate. Stringent selection criteria were set in selecting the cases and suitable controls. A ratio of 1:3 for case:control was selected for getting the optimum statistical significance from the data generated. The paper describes the methodology of dosimetric survey and the analysis of dose data based on case and controls

  6. Type I error and statistical power of the Mantel-Haenszel procedure for detecting DIF: a meta-analysis.

    Science.gov (United States)

    Guilera, Georgina; Gómez-Benito, Juana; Hidalgo, Maria Dolores; Sánchez-Meca, Julio

    2013-12-01

    This article presents a meta-analysis of studies investigating the effectiveness of the Mantel-Haenszel (MH) procedure when used to detect differential item functioning (DIF). Studies were located electronically in the main databases, representing the codification of 3,774 different simulation conditions, 1,865 related to Type I error and 1,909 to statistical power. The homogeneity of effect-size distributions was assessed by the Q statistic. The extremely high heterogeneity in both error rates (I² = 94.70) and power (I² = 99.29), due to the fact that numerous studies test the procedure in extreme conditions, means that the main interest of the results lies in explaining the variability in detection rates. One-way analysis of variance was used to determine the effects of each variable on detection rates, showing that the MH test was more effective when purification procedures were used, when the data fitted the Rasch model, when test contamination was below 20%, and with sample sizes above 500. The results imply a series of recommendations for practitioners who wish to study DIF with the MH test. A limitation, one inherent to all meta-analyses, is that not all the possible moderator variables, or the levels of variables, have been explored. This serves to remind us of certain gaps in the scientific literature (i.e., regarding the direction of DIF or variances in ability distribution) and is an aspect that methodologists should consider in future simulation studies. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  7. The construct validity of the Major Depression Inventory

    DEFF Research Database (Denmark)

    Nielsen, Marie Germund; Ørnbøl, Eva; Vestergaard, Mogens

    2017-01-01

    Objective We aimed to assess the measurement properties of the ten-item Major Depression Inventory when used on clinical suspicion in general practice by performing a Rasch analysis. Methods General practitioners asked consecutive persons to respond to the web-based Major Depression Inventory...... on clinical suspicion of depression. We included 22 practices and 245 persons. Rasch analysis was performed using RUMM2030 software. The Rasch model fit suggests that all items contribute to a single underlying trait (defined as internal construct validity). Mokken analysis was used to test dimensionality...... for gender, age, work status and education. The Rasch and Mokken analyses revealed two dimensions, but the Major Depression Inventory showed fit to one scale if items 9 and 10 were excluded. Conclusion Our study indicated scalability problems in the current version of the Major Depression Inventory...

  8. Review: Reiner Keller, Andreas Hirseland, Werner Schneider & Willy Viehöver (Eds. (2006. Handbuch Sozialwissenschaftliche Diskursanalyse. Band I: Theorien und Methoden [Handbook on Discourse Analysis in Social Sciences. Theories and Methods

    Directory of Open Access Journals (Sweden)

    Steffen Großkopf

    2008-01-01

    Full Text Available The handbook gives a general overview of the established—but increasingly complex—theoretical and methodological practice of discourse analysis. The attempt is made to systematize the diversity of discourse analysis, with its different historical roots and fields of research in the social sciences, even though the focus is mainly on FOUCAULT's approach. Thus, the handbook has to be understood as an important step towards a insertion of discourse analysis into social science. Although there are unavoidable contradictions between the articles—almost because of the open theoretical foundations—the handbook characterizes, as a whole, discourse analysis as a heterogeneous strategy of research rather than as a stringent method. With this approach, it can be a helpful guide for the reader’s own research projects. However, if one is looking for a precise method, the investment of time in discourse analysis could be wasted. URN: urn:nbn:de:0114-fqs0801143

  9. SeaWiFS technical report series. Volume 11: Analysis of selected orbit propagation models for the SeaWiFS mission

    Science.gov (United States)

    Patt, Frederick S.; Hoisington, Charles M.; Gregg, Watson W.; Coronado, Patrick L.; Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Indest, A. W. (Editor)

    1993-01-01

    An analysis of orbit propagation models was performed by the Mission Operations element of the Sea-viewing Wide Field-of-View Sensor (SeaWiFS) Project, which has overall responsibility for the instrument scheduling. The orbit propagators selected for this analysis are widely available general perturbations models. The analysis includes both absolute accuracy determination and comparisons of different versions of the models. The results show that all of the models tested meet accuracy requirements for scheduling and data acquisition purposes. For internal Project use the SGP4 propagator, developed by the North American Air Defense (NORAD) Command, has been selected. This model includes atmospheric drag effects and, therefore, provides better accuracy. For High Resolution Picture Transmission (HRPT) ground stations, which have less stringent accuracy requirements, the publicly available Brouwer-Lyddane models are recommended. The SeaWiFS Project will make available portable source code for a version of this model developed by the Data Capture Facility (DCF).

  10. Analysis of multiuser mixed RF/FSO relay networks for performance improvements in Cloud Computing-Based Radio Access Networks (CC-RANs)

    Science.gov (United States)

    Alimi, Isiaka A.; Monteiro, Paulo P.; Teixeira, António L.

    2017-11-01

    The key paths toward the fifth generation (5G) network requirements are towards centralized processing and small-cell densification systems that are implemented on the cloud computing-based radio access networks (CC-RANs). The increasing recognitions of the CC-RANs can be attributed to their valuable features regarding system performance optimization and cost-effectiveness. Nevertheless, realization of the stringent requirements of the fronthaul that connects the network elements is highly demanding. In this paper, considering the small-cell network architectures, we present multiuser mixed radio-frequency/free-space optical (RF/FSO) relay networks as feasible technologies for the alleviation of the stringent requirements in the CC-RANs. In this study, we use the end-to-end (e2e) outage probability, average symbol error probability (ASEP), and ergodic channel capacity as the performance metrics in our analysis. Simulation results show the suitability of deployment of mixed RF/FSO schemes in the real-life scenarios.

  11. A meta-analysis of response-time tests of the sequential two-systems model of moral judgment.

    Science.gov (United States)

    Baron, Jonathan; Gürçay, Burcu

    2017-05-01

    The (generalized) sequential two-system ("default interventionist") model of utilitarian moral judgment predicts that utilitarian responses often arise from a system-two correction of system-one deontological intuitions. Response-time (RT) results that seem to support this model are usually explained by the fact that low-probability responses have longer RTs. Following earlier results, we predicted response probability from each subject's tendency to make utilitarian responses (A, "Ability") and each dilemma's tendency to elicit deontological responses (D, "Difficulty"), estimated from a Rasch model. At the point where A = D, the two responses are equally likely, so probability effects cannot account for any RT differences between them. The sequential two-system model still predicts that many of the utilitarian responses made at this point will result from system-two corrections of system-one intuitions, hence should take longer. However, when A = D, RT for the two responses was the same, contradicting the sequential model. Here we report a meta-analysis of 26 data sets, which replicated the earlier results of no RT difference overall at the point where A = D. The data sets used three different kinds of moral judgment items, and the RT equality at the point where A = D held for all three. In addition, we found that RT increased with A-D. This result holds for subjects (characterized by Ability) but not for items (characterized by Difficulty). We explain the main features of this unanticipated effect, and of the main results, with a drift-diffusion model.

  12. Wind energy at the North Sea. A societal cost benefit analysis; Windenergie op de Noordzee. Een maatschappelijke kosten-batenanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Verrips, A.; Lijesen, M. [Centraal Planbureau CPB, Den Haag (Netherlands); De Vries, H.; Seebregts, A. [ECN Beleidsstudies, Petten (Netherlands)

    2005-09-01

    A social cost-benefit analysis (cba) of an investment in wind turbines at the North Sea has been conducted. The analysis reveals that such an investment will only increase welfare if it is done gradually and combined with strict climate policy measures. Building 6000 MW of wind parks at the North Sea by 2020 is economically unviable in all scenarios, variants and sensitivity analyses performed in this study. In a version with more gradual investments in the Strong Europe scenario (with strict climate policy), the balance will be slightly negative. If more favourable assumptions are used on cost decreases over time, higher fuel prices, higher emission prices or a lower discount factor, this would turn the balance to slightly positive. World oil-price developments in the coming decades are not expected to render wind energy economically viable in the absence of climate policy. [Dutch] Een maatschappelijke kosten-batenanalyse (KBA) van het plaatsen en in gebruik nemen van windparken op de Noordzee is uitgevoerd. Uit de analyse blijkt dat maatschappelijk rendabel investeren in windenergie op zee een zeer geleidelijke capaciteitsopbouw en een stringent internationaal klimaatbeleid vereist. Het voor 2020 aanleggen van windparken in zee met een totale omvang tot 6000 MW blijkt in alle geanalyseerde scenario's, varianten en hierop toegepaste gevoeligheidsanalyses maatschappelijk onrendabel te zijn. In een variant met een meer gefaseerde aanleg van windparken wordt in het zogenaamde Strong Europe-scenario (stringent klimaatbeleid) het negatieve saldo van kosten en baten beperkt. Bij wat gunstiger veronderstellingen rondom kostendalingen in de tijd, hogere brandstofprijzen, hogere CO2-emissiehandelprijzen of een wat lagere disconteringsvoet kan deze variant in de plus komen. Bij het ontbreken van een stringent internationaal klimaatbeleid bieden de te verwachten wereldmarktprijzen van olie de komende decennia onvoldoende perspectief om windenergie op zee rendabel te

  13. Wind energy at the North Sea. A societal cost benefit analysis; Windenergie op de Noordzee. Een maatschappelijke kosten-batenanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Verrips, A.; Lijesen, M. [Centraal Planbureau CPB, Den Haag (Netherlands); De Vries, H.; Seebregts, A. [ECN Beleidsstudies, Petten (Netherlands)

    2005-09-15

    A social cost-benefit analysis (cba) of an investment in wind turbines at the North Sea has been conducted. The analysis reveals that such an investment will only increase welfare if it is done gradually and combined with strict climate policy measures. Building 6000 MW of wind parks at the North Sea by 2020 is economically unviable in all scenarios, variants and sensitivity analyses performed in this study. In a version with more gradual investments in the Strong Europe scenario (with strict climate policy), the balance will be slightly negative. If more favourable assumptions are used on cost decreases over time, higher fuel prices, higher emission prices or a lower discount factor, this would turn the balance to slightly positive. World oil-price developments in the coming decades are not expected to render wind energy economically viable in the absence of climate policy. [Dutch] Een maatschappelijke kosten-batenanalyse (KBA) van het plaatsen en in gebruik nemen van windparken op de Noordzee is uitgevoerd. Uit de analyse blijkt dat maatschappelijk rendabel investeren in windenergie op zee een zeer geleidelijke capaciteitsopbouw en een stringent internationaal klimaatbeleid vereist. Het voor 2020 aanleggen van windparken in zee met een totale omvang tot 6000 MW blijkt in alle geanalyseerde scenario's, varianten en hierop toegepaste gevoeligheidsanalyses maatschappelijk onrendabel te zijn. In een variant met een meer gefaseerde aanleg van windparken wordt in het zogenaamde Strong Europe-scenario (stringent klimaatbeleid) het negatieve saldo van kosten en baten beperkt. Bij wat gunstiger veronderstellingen rondom kostendalingen in de tijd, hogere brandstofprijzen, hogere CO2-emissiehandelprijzen of een wat lagere disconteringsvoet kan deze variant in de plus komen. Bij het ontbreken van een stringent internationaal klimaatbeleid bieden de te verwachten wereldmarktprijzen van olie de komende decennia onvoldoende perspectief om windenergie op zee rendabel te

  14. Data Envelopment Analysis of different climate policy scenarios

    International Nuclear Information System (INIS)

    Bosetti, Valentina; Buchner, Barbara

    2009-01-01

    Recent developments in the political, scientific and economic debate on climate change suggest that it is of critical importance to develop new approaches able to compare policy scenarios for their environmental effectiveness, their distributive effects, their enforceability, their costs and many other dimensions. This paper discusses a quantitative methodology to assess the relative performance of different climate policy scenarios when accounting for their long-term economic, social and environmental impacts. The proposed procedure is based on Data Envelopment Analysis, here employed in evaluating the relative efficiency of eleven global climate policy scenarios. The methodology provides a promising comparison framework; it can be seen as a way of setting some basic guidelines to frame further debates and negotiations and can be flexibly adopted and modified by decision makers to obtain relevant information for policy design. Three major findings emerge from this analysis: (1) stringent climate policies can outperform less ambitious proposals if all sustainability dimensions are taken into account; (2) a carefully chosen burden-sharing rule is able to bring together climate stabilisation and equity considerations; and (3) the most inefficient strategy results from the failure to negotiate a post-2012 global climate agreement. (author)

  15. Real time video analysis to monitor neonatal medical condition

    Science.gov (United States)

    Shirvaikar, Mukul; Paydarfar, David; Indic, Premananda

    2017-05-01

    One in eight live births in the United States is premature and these infants have complications leading to life threatening events such as apnea (pauses in breathing), bradycardia (slowness of heart) and hypoxia (oxygen desaturation). Infant movement pattern has been hypothesized as an important predictive marker for these life threatening events. Thus estimation of movement along with behavioral states, as a precursor of life threatening events, can be useful for risk stratification of infants as well as for effective management of disease state. However, more important and challenging is the determination of the behavioral state of the infant. This information includes important cues such as sleep position and the status of the eyes, which are important markers for neonatal neurodevelopment state. This paper explores the feasibility of using real time video analysis to monitor the condition of premature infants. The image of the infant can be segmented into regions to localize and focus on specific areas of interest. Analysis of the segmented regions can be performed to identify different parts of the body including the face, arms, legs and torso. This is necessary due to real-time processing speed considerations. Such a monitoring system would be of great benefit as an aide to medical staff in neonatal hospital settings requiring constant surveillance. Any such system would have to satisfy extremely stringent reliability and accuracy requirements, before it can be deployed in a hospital care unit, due to obvious reasons. The effect of lighting conditions and interference will have to be mitigated to achieve such performance.

  16. Cost-benefit analysis for design of environmentally conscious manufacturing

    International Nuclear Information System (INIS)

    Matysiak, L.M.

    1993-01-01

    In recent years, much attention has been focused on reducing the environmental impacts of products and manufacturing processes. Concerned about rising compliance costs and stringent regulatory requirements, companies are carefully evaluating the environmental impacts of their products. In response, designers, engineers, and managers are beginning to use life-cycle analysis, design for environment techniques, and environmentally conscious manufacturing (ECM) as tools to help them to not only do what is best for the environment, but also to do what is best for their company. These tools are also a useful aid in evaluating the trade-offs that may exist between different product and process alternatives. However, how does one choose the optimal solution from these various product and process alternatives? Cost versus benefit analysis is an effective tool that can be used to evaluate various manufacturing alternatives and to choose a solution that is both cost effective and environmentally compatible. Many companies are beginning to use cost benefit analyses as a means to justify product or process modifications that result in a benefit to the environment

  17. Is the reduction of dimensionality to a small number of features always necessary in constructing predictive models for analysis of complex diseases or behaviours?

    Science.gov (United States)

    Zollanvari, Amin; Saccone, Nancy L; Bierut, Laura J; Ramoni, Marco F; Alterovitz, Gil

    2011-01-01

    Gene expression and genome wide association data have provided researchers the opportunity to study many complex traits and diseases. When designing prognostic and predictive models capable of phenotypic classification in this area, significant reduction of dimensionality through stringent filtering and/or feature selection is often deemed imperative. Here, this work challenges this presumption through both theoretical and empirical analysis. This work demonstrates that by a proper compromise between structure of the selected model and the number of features, one is able to achieve better performance even in large dimensionality. The inclusion of many genes/variants in the classification rules can help shed new light on the analysis of complex traitstraits that are typically determined by many causal variants with small effect size.

  18. Modern psychometric approaches to analysis of scales for health-related quality of life

    DEFF Research Database (Denmark)

    Bjorner, Jakob Bue; Bech, Per

    2016-01-01

    In recent years, much effort has been invested in the development of new instruments for assessment of health-related quality of life (HRQOL). For many new instruments, modern psychometric methods, such as item response theory (IRT) models, have been used, either as supplemental to classical...... psychometric testing or as the primary methodological approach. We will use the term modern psychometric methods to refer to psychometric methods for multi-item scales that (1) examine the contribution of each item to the measurement properties of the overall scale and (2) recognize that items are categorical....... The models include Rasch models (Rasch 1980; Fischer and Molenaar 1995), other IRT models (Samejima 1969; van der Linden and Hambleton 1997), and factor analytic models for categorical data (Muthén 1984). “Modern” psychometric methods have actually a rather long history within psychiatric research (both...

  19. Decision analysis multicriteria analysis

    International Nuclear Information System (INIS)

    Lombard, J.

    1986-09-01

    The ALARA procedure covers a wide range of decisions from the simplest to the most complex one. For the simplest one the engineering judgement is generally enough and the use of a decision aiding technique is therefore not necessary. For some decisions the comparison of the available protection option may be performed from two or a few criteria (or attributes) (protection cost, collective dose,...) and the use of rather simple decision aiding techniques, like the Cost Effectiveness Analysis or the Cost Benefit Analysis, is quite enough. For the more complex decisions, involving numerous criteria or for decisions involving large uncertainties or qualitative judgement the use of these techniques, even the extended cost benefit analysis, is not recommended and appropriate techniques like multi-attribute decision aiding techniques are more relevant. There is a lot of such particular techniques and it is not possible to present all of them. Therefore only two broad categories of multi-attribute decision aiding techniques will be presented here: decision analysis and the outranking analysis

  20. Behavioral metabolomics analysis identifies novel neurochemical signatures in methamphetamine sensitization

    Science.gov (United States)

    Adkins, Daniel E.; McClay, Joseph L.; Vunck, Sarah A.; Batman, Angela M.; Vann, Robert E.; Clark, Shaunna L.; Souza, Renan P.; Crowley, James J.; Sullivan, Patrick F.; van den Oord, Edwin J.C.G.; Beardsley, Patrick M.

    2014-01-01

    Behavioral sensitization has been widely studied in animal models and is theorized to reflect neural modifications associated with human psychostimulant addiction. While the mesolimbic dopaminergic pathway is known to play a role, the neurochemical mechanisms underlying behavioral sensitization remain incompletely understood. In the present study, we conducted the first metabolomics analysis to globally characterize neurochemical differences associated with behavioral sensitization. Methamphetamine-induced sensitization measures were generated by statistically modeling longitudinal activity data for eight inbred strains of mice. Subsequent to behavioral testing, nontargeted liquid and gas chromatography-mass spectrometry profiling was performed on 48 brain samples, yielding 301 metabolite levels per sample after quality control. Association testing between metabolite levels and three primary dimensions of behavioral sensitization (total distance, stereotypy and margin time) showed four robust, significant associations at a stringent metabolome-wide significance threshold (false discovery rate < 0.05). Results implicated homocarnosine, a dipeptide of GABA and histidine, in total distance sensitization, GABA metabolite 4-guanidinobutanoate and pantothenate in stereotypy sensitization, and myo-inositol in margin time sensitization. Secondary analyses indicated that these associations were independent of concurrent methamphetamine levels and, with the exception of the myo-inositol association, suggest a mechanism whereby strain-based genetic variation produces specific baseline neurochemical differences that substantially influence the magnitude of MA-induced sensitization. These findings demonstrate the utility of mouse metabolomics for identifying novel biomarkers, and developing more comprehensive neurochemical models, of psychostimulant sensitization. PMID:24034544

  1. Comparison and Analysis of Regulatory and Derived Requirements for Certain DOE Spent Nuclear Fuel Shipments; Lessons Learned for Future Spent Fuel Transportation Campaigns

    International Nuclear Information System (INIS)

    Kramer, George L.; Fawcett, Rick L.; Rieke, Philip C.

    2003-01-01

    Radioactive materials transportation is stringently regulated by the Department of Transportation and the Nuclear Regulatory Commission to protect the public and the environment. As a Federal agency, however, the U.S. Department of Energy (DOE) must seek State, Tribal and local input on safety issues for certain transportation activities. This interaction has invariably resulted in the imposition of extra-regulatory requirements, greatly increasing transportation costs and delaying schedules while not significantly enhancing the level of safety. This paper discusses the results an analysis of the regulatory and negotiated requirements established for a July 1998 shipment of spent nuclear fuel from foreign countries through the west coast to the Idaho National Engineering and Environmental Laboratory (INEEL). Staff from the INEEL Nuclear Materials Engineering and Disposition Department undertook the analysis in partnership with HMTC, to discover if there were instances where requirements derived from stakeholder interactions duplicate, contradict, or otherwise overlap with regulatory requirements. The study exhaustively lists and classifies applicable Department of Transportation (DOT) and Nuclear Regulatory Commission (NRC) regulations. These are then compared with a similarly classified list of requirements from the Environmental Impact Statements (EIS) and those developed during stakeholder negotiations. Comparison and analysis reveals numerous attempts to reduce transportation risk by imposing more stringent safety measures than those required by DOT and NRC. These usually took the form of additional inspection, notification and planning requirements. There are also many instances of overlap with, and duplication of regulations. Participants will gain a greater appreciation for the need to understand the risk-oriented basis of the radioactive materials regulations and their effectiveness in ensuring safety when negotiating extra-regulatory requirements

  2. Parametric analyses of summative scores may lead to conflicting inferences when comparing groups: A simulation study.

    Science.gov (United States)

    Khan, Asaduzzaman; Chien, Chi-Wen; Bagraith, Karl S

    2015-04-01

    To investigate whether using a parametric statistic in comparing groups leads to different conclusions when using summative scores from rating scales compared with using their corresponding Rasch-based measures. A Monte Carlo simulation study was designed to examine between-group differences in the change scores derived from summative scores from rating scales, and those derived from their corresponding Rasch-based measures, using 1-way analysis of variance. The degree of inconsistency between the 2 scoring approaches (i.e. summative and Rasch-based) was examined, using varying sample sizes, scale difficulties and person ability conditions. This simulation study revealed scaling artefacts that could arise from using summative scores rather than Rasch-based measures for determining the changes between groups. The group differences in the change scores were statistically significant for summative scores under all test conditions and sample size scenarios. However, none of the group differences in the change scores were significant when using the corresponding Rasch-based measures. This study raises questions about the validity of the inference on group differences of summative score changes in parametric analyses. Moreover, it provides a rationale for the use of Rasch-based measures, which can allow valid parametric analyses of rating scale data.

  3. Joint analysis is more efficient than replication-based analysis for two-stage genome-wide association studies.

    Science.gov (United States)

    Skol, Andrew D; Scott, Laura J; Abecasis, Gonçalo R; Boehnke, Michael

    2006-02-01

    Genome-wide association is a promising approach to identify common genetic variants that predispose to human disease. Because of the high cost of genotyping hundreds of thousands of markers on thousands of subjects, genome-wide association studies often follow a staged design in which a proportion (pi(samples)) of the available samples are genotyped on a large number of markers in stage 1, and a proportion (pi(samples)) of these markers are later followed up by genotyping them on the remaining samples in stage 2. The standard strategy for analyzing such two-stage data is to view stage 2 as a replication study and focus on findings that reach statistical significance when stage 2 data are considered alone. We demonstrate that the alternative strategy of jointly analyzing the data from both stages almost always results in increased power to detect genetic association, despite the need to use more stringent significance levels, even when effect sizes differ between the two stages. We recommend joint analysis for all two-stage genome-wide association studies, especially when a relatively large proportion of the samples are genotyped in stage 1 (pi(samples) >or= 0.30), and a relatively large proportion of markers are selected for follow-up in stage 2 (pi(markers) >or= 0.01).

  4. Branched Adaptive Testing with a Rasch-Model-Calibrated Test: Analysing Item Presentation's Sequence Effects Using the Rasch-Model-Based LLTM

    Science.gov (United States)

    Kubinger, Klaus D.; Reif, Manuel; Yanagida, Takuya

    2011-01-01

    Item position effects provoke serious problems within adaptive testing. This is because different testees are necessarily presented with the same item at different presentation positions, as a consequence of which comparing their ability parameter estimations in the case of such effects would not at all be fair. In this article, a specific…

  5. Performance analysis

    International Nuclear Information System (INIS)

    2008-05-01

    This book introduces energy and resource technology development business with performance analysis, which has business division and definition, analysis of current situation of support, substance of basic plan of national energy, resource technique development, selection of analysis index, result of performance analysis by index, performance result of investigation, analysis and appraisal of energy and resource technology development business in 2007.

  6. Observation of the rare $B^0_s\\to\\mu^+\\mu^-$ decay from the combined analysis of CMS and LHCb data

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Lauwers, Jasper; Luyckx, Sten; Ochesanu, Silvia; Rougny, Romain; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Daci, Nadir; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Maes, Michael; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Dobur, Didar; Favart, Laurent; Gay, Arnaud; Grebenyuk, Anastasia; Léonard, Alexandre; Mohammadi, Abdollah; Perniè, Luca; Randle-conde, Aidan; Reis, Thomas; Seva, Tomislav; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Zenoni, Florian; Adler, Volker; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Costantini, Silvia; Crucy, Shannon; Dildick, Sven; Fagot, Alexis; Garcia, Guillaume; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Nuttens, Claude; Pagano, Davide; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Dos Reis Martins, Thiago; Mora Herrera, Clemencia; Pol, Maria Elena; Rebello Teles, Patricia; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Melo Da Costa, Eliza; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Malbouisson, Helena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santaolalla, Javier; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Bernardes, Cesar Augusto; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Aleksandrov, Aleksandar; Genchev, Vladimir; Hadjiiska, Roumyana; Iaydjiev, Plamen; Marinov, Andrey; Piperov, Stefan; Rodozov, Mircho; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Cheng, Tongguang; Du, Ran; Jiang, Chun-Hua; Plestina, Roko; Romeo, Francesco; Tao, Junquan; Wang, Zheng; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Zou, Wei; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Mekterovic, Darko; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Ellithi Kamel, Ali; Mahmoud, Mohammed; Radi, Amr; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Charlot, Claude; Dahms, Torsten; Dalchenko, Mykhailo; Dobrzynski, Ludwik; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Mastrolorenzo, Luca; Miné, Philippe; Mironov, Camelia; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Regnard, Simon; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Veelken, Christian; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Skovpen, Kirill; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Beaupere, Nicolas; Boudoul, Gaelle; Bouvier, Elvire; Brochet, Sébastien; Carrillo Montoya, Camilo Andres; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Xiao, Hong; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Bontenackels, Michael; Edelhoff, Matthias; Feld, Lutz; Heister, Arno; Hindrichs, Otto; Klein, Katja; Ostapchuk, Andrey; Raupach, Frank; Sammet, Jan; Schael, Stefan; Schulte, Jan-Frederik; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Erdmann, Martin; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Weber, Martin; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Künsken, Andreas; Lingemann, Joschka; Nowack, Andreas; Nugent, Ian Michael; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Asin, Ivan; Bartosik, Nazar; Behr, Joerg; Behrens, Ulf; Bell, Alan James; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dolinska, Ganna; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Garay Garcia, Jasone; Geiser, Achim; Gunnellini, Paolo; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Korol, Ievgen; Krücker, Dirk; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Nayak, Aruna; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Roland, Benoit; Ron, Elias; Sahin, Mehmet Özgür; Salfeld-Nebgen, Jakob; Saxena, Pooja; Schoerner-Sadenius, Thomas; Schröder, Matthias; Seitz, Claudia; Spannagel, Simon; Vargas Trevino, Andrea Del Rocio; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Görner, Martin; Haller, Johannes; Hoffmann, Malte; Höing, Rebekka Sophie; Junkes, Alexandra; Kirschenmann, Henning; Klanner, Robert; Kogler, Roman; Lange, Jörn; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Ott, Jochen; Peiffer, Thomas; Perieanu, Adrian; Pietsch, Niklas; Poehlsen, Jennifer; Pöhlsen, Thomas; Rathjens, Denis; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Seidel, Markus; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Feindt, Michael; Frensch, Felix; Giffels, Manuel; Gilbert, Andrew; Hartmann, Frank; Hauth, Thomas; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Kuznetsova, Ekaterina; Lobelle Pardo, Patricia; Mozer, Matthias Ulrich; Müller, Thomas; Müller, Thomas; Nürnberg, Andreas; Quast, Gunter; Rabbertz, Klaus; Röcker, Steffen; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weiler, Thomas; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Markou, Athanasios; Markou, Christos; Psallidas, Andreas; Topsis-Giotis, Iasonas; Agapitos, Antonis; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Stiliaris, Efstathios; Aslanoglou, Xenofon; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Strologas, John; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Makovec, Alajos; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Sahoo, Niladribihari; Swain, Sanjay Kumar; Beri, Suman Bala; Bhatnagar, Vipin; Gupta, Ruchi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Manjit; Kumar, Ramandeep; Mittal, Monika; Nishu, Nishu; Singh, Jasbir; Kumar, Ashok; Kumar, Arun; Ahuja, Sudha; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Banerjee, Sunanda; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Modak, Atanu; Mukherjee, Swagata; Roy, Debarati; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Bhowmik, Sandeep; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Sudhakar, Katta; Wickramage, Nadeesha; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Goldouzian, Reza; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Selvaggi, Giovanna; Sharma, Archana; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gallo, Elisabetta; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Ferretti, Roberta; Ferro, Fabrizio; Lo Vetere, Maurizio; Robutti, Enrico; Tosi, Silvano; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Lucchini, Marco Toliman; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; Dall'Osso, Martino; Dorigo, Tommaso; Dosselli, Umberto; Galanti, Mario; Gasparini, Fabrizio; Gasparini, Ugo; Giubilato, Piero; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Gabusi, Michele; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Spiezia, Aniello; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Moon, Chang-Seong; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Vernieri, Caterina; Barone, Luciano; Cavallari, Francesca; D'imperio, Giulia; Del Re, Daniele; Diemoz, Marcella; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Paramatti, Riccardo; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Soffi, Livia; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Casasso, Stefano; Costa, Marco; Degano, Alessandro; Demaria, Natale; Finco, Linda; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Tamponi, Umberto; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Schizzi, Andrea; Umer, Tomo; Zanetti, Anna; Chang, Sunghyun; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Park, Hyangkyu; Sakharov, Alexandre; Son, Dong-Chul; Kim, Tae Jeong; Kim, Jae Yool; Song, Sanghyeon; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kyong Sei; Park, Sung Keun; Roh, Youn; Yoo, Hwi Dong; Choi, Minkyoo; Kim, Ji Hyun; Park, Inkyu; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Donghyun; Kwon, Eunhyang; Lee, Jongseok; Yu, Intae; Juodagalvis, Andrius; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Casimiro Linares, Edgar; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Reucroft, Steve; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Khurshid, Taimoor; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michał; Wolszczak, Weronika; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Lloret Iglesias, Lara; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Varela, Joao; Vischia, Pietro; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Konoplyanikov, Viktor; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Skatchkov, Nikolai; Smirnov, Vitaly; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Semenov, Sergey; Spiridonov, Alexander; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Ekmedzic, Marko; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Senghi Soares, Mara; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Brun, Hugues; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Duarte Campderros, Jordi; Fernandez, Marcos; Gomez, Gervasio; Graziano, Alberto; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Bernet, Colin; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Bondu, Olivier; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Colafranceschi, Stefano; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; David Tinoco Mendes, Andre; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Di Marco, Emanuele; Dobson, Marc; Dordevic, Milos; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Franzoni, Giovanni; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Glege, Frank; Guida, Roberto; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Hansen, Magnus; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kousouris, Konstantinos; Krajczar, Krisztian; Lecoq, Paul; Lourenco, Carlos; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Marrouche, Jad; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Perrozzi, Luca; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pimiä, Martti; Piparo, Danilo; Plagge, Michael; Racz, Attila; Rolandi, Gigi; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Steggemann, Jan; Stieger, Benjamin; Stoye, Markus; Takahashi, Yuta; Treille, Daniel; Tsirou, Andromachi; Veres, Gabor Istvan; Wardle, Nicholas; Wöhri, Hermine Katharina; Wollny, Heiner; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; Kotlinski, Danek; Langenegger, Urs; Renker, Dieter; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Dünser, Marc; Eller, Philipp; Grab, Christoph; Hits, Dmitry; Hoss, Jan; Lustermann, Werner; Mangano, Boris; Marini, Andrea Carlo; Marionneau, Matthieu; Martinez Ruiz del Arbol, Pablo; Masciovecchio, Mario; Meister, Daniel; Mohr, Niklas; Musella, Pasquale; Nägeli, Christoph; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pauss, Felicitas; Peruzzi, Marco; Quittnat, Milena; Rebane, Liis; Rossini, Marco; Starodumov, Andrei; Takahashi, Maiko; Theofilatos, Konstantinos; Wallny, Rainer; Weber, Hannsjoerg Artur; Amsler, Claude; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Hinzmann, Andreas; Hreus, Tomas; Kilminster, Benjamin; Lange, Clemens; Millan Mejias, Barbara; Ngadiuba, Jennifer; Pinna, Deborah; Robmann, Peter; Ronga, Frederic Jean; Taroni, Silvia; Verzetti, Mauro; Yang, Yong; Cardaci, Marco; Chen, Kuan-Hsin; Ferro, Cristina; Kuo, Chia-Ming; Lin, Willis; Lu, Yun-Ju; Volpe, Roberta; Yu, Shin-Shan; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Dietz, Charles; Grundler, Ulysses; Hou, George Wei-Shu; Kao, Kai-Yi; Liu, Yueh-Feng; Lu, Rong-Shyang; Majumder, Devdatta; Petrakou, Eleni; Tzeng, Yeng-Ming; Wilken, Rachel; Asavapibhop, Burin; Singh, Gurpreet; Srimanobhas, Norraphat; Suwonjandee, Narumon; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Mehmet; Akin, Ilina Vasileva; Bilin, Bugra; Bilmis, Selcuk; Gamsizkan, Halil; Isildak, Bora; Karapinar, Guler; Ocalan, Kadir; Sekmen, Sezen; Surat, Ugur Emrah; Yalvac, Metin; Zeyrek, Mehmet; Albayrak, Elif Asli; Gülmez, Erhan; Kaya, Mithat; Kaya, Ozlem; Yetkin, Taylan; Cankocak, Kerem; Vardarlı, Fuat Ilkehan; Levchuk, Leonid; Sorokin, Pavel; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Meng, Zhaoxia; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Sakuma, Tai; Senkin, Sergey; Smith, Vincent J; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Tomalin, Ian R; Williams, Thomas; Womersley, William John; Worm, Steven; Baber, Mark; Bainbridge, Robert; Buchmuller, Oliver; Burton, Darren; Colling, David; Cripps, Nicholas; Dauncey, Paul; Davies, Gavin; Della Negra, Michel; Dunne, Patrick; Ferguson, William; Fulcher, Jonathan; Futyan, David; Hall, Geoffrey; Iles, Gregory; Jarvis, Martyn; Karapostoli, Georgia; Kenzie, Matthew; Lane, Rebecca; Lucas, Robyn; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Mathias, Bryn; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Raymond, David Mark; Rogerson, Samuel; Rose, Andrew; Seez, Christopher; Sharp, Peter; Tapper, Alexander; Vazquez Acosta, Monica; Virdee, Tejinder; Zenz, Seth Conrad; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leggat, Duncan; Leslie, Dawn; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Dittmann, Jay; Hatakeyama, Kenichi; Kasmi, Azeddine; Liu, Hongxuan; Scarborough, Tara; Charaf, Otman; Cooper, Seth; Henderson, Conor; Rumerio, Paolo; Avetisyan, Aram; Bose, Tulika; Fantasia, Cory; Lawson, Philip; Richardson, Clint; Rohlf, James; St John, Jason; Sulak, Lawrence; Alimena, Juliette; Berry, Edmund; Bhattacharya, Saptaparna; Christopher, Grant; Cutts, David; Demiragli, Zeynep; Dhingra, Nitish; Ferapontov, Alexey; Garabedian, Alex; Heintz, Ulrich; Kukartsev, Gennadiy; Laird, Edward; Landsberg, Greg; Luk, Michael; Narain, Meenakshi; Segala, Michael; Sinthuprasith, Tutanon; Speer, Thomas; Swanson, Joshua; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Erbacher, Robin; Gardner, Michael; Ko, Winston; Lander, Richard; Mulhearn, Michael; Pellett, Dave; Pilot, Justin; Ricci-Tam, Francesca; Shalhout, Shalhout; Smith, John; Squires, Michael; Stolp, Dustin; Tripathi, Mani; Wilbur, Scott; Yohay, Rachel; Cousins, Robert; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Rakness, Gregory; Takasugi, Eric; Valuev, Vyacheslav; Weber, Matthias; Burt, Kira; Clare, Robert; Ellison, John Anthony; Gary, J William; Hanson, Gail; Heilman, Jesse; Ivova Rikova, Mirena; Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Long, Owen Rosser; Luthra, Arun; Malberti, Martina; Olmedo Negrete, Manuel; Shrinivas, Amithabh; Sumowidagdo, Suharyo; Wimpenny, Stephen; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; D'Agnolo, Raffaele Tito; Holzner, André; Kelley, Ryan; Klein, Daniel; Kovalskyi, Dmytro; Letts, James; Macneill, Ian; Olivito, Dominick; Padhi, Sanjay; Palmer, Christopher; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tu, Yanjun; Vartak, Adish; Welke, Charles; Würthwein, Frank; Yagil, Avraham; Barge, Derek; Bradmiller-Feld, John; Campagnari, Claudio; Danielson, Thomas; Dishaw, Adam; Dutta, Valentina; Flowers, Kristen; Franco Sevilla, Manuel; Geffert, Paul; George, Christopher; Golf, Frank; Gouskos, Loukas; Incandela, Joe; Justus, Christopher; Mccoll, Nickolas; Richman, Jeffrey; Stuart, David; To, Wing; West, Christopher; Yoo, Jaehyeok; Apresyan, Artur; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Duarte, Javier; Mott, Alexander; Newman, Harvey B; Pena, Cristian; Pierini, Maurizio; Spiropulu, Maria; Vlimant, Jean-Roch; Wilkinson, Richard; Xie, Si; Zhu, Ren-Yuan; Azzolini, Virginia; Calamba, Aristotle; Carlson, Benjamin; Ferguson, Thomas; Iiyama, Yutaro; Paulini, Manfred; Russ, James; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Ford, William T; Gaz, Alessandro; Krohn, Michael; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Wagner, Stephen Robert; Alexander, James; Chatterjee, Avishek; Chaves, Jorge; Chu, Jennifer; Dittmer, Susan; Eggert, Nicholas; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Ryd, Anders; Salvati, Emmanuele; Skinnari, Louise; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Tucker, Jordan; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hanlon, Jim; Hare, Daryl; Harris, Robert M; Hirschauer, James; Hooberman, Benjamin; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Kaadze, Ketino; Klima, Boaz; Kreis, Benjamin; Kwan, Simon; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Martinez Outschoorn, Verena Ingrid; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mishra, Kalanand; Mrenna, Stephen; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Prokofyev, Oleg; Sexton-Kennedy, Elizabeth; Sharma, Seema; Soha, Aron; Spalding, William J; Spiegel, Leonard; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitbeck, Andrew; Whitmore, Juliana; Yang, Fan; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Carver, Matthew; Curry, David; Das, Souvik; De Gruttola, Michele; Di Giovanni, Gian Piero; Field, Richard D; Fisher, Matthew; Furic, Ivan-Kresimir; Hugon, Justin; Konigsberg, Jacobo; Korytov, Andrey; Kypreos, Theodore; Low, Jia Fu; Matchev, Konstantin; Mei, Hualin; Milenovic, Predrag; Mitselmakher, Guenakh; Muniz, Lana; Rinkevicius, Aurelijus; Shchutska, Lesya; Snowball, Matthew; Sperka, David; Yelton, John; Zakaria, Mohammed; Hewamanage, Samantha; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Diamond, Brendan; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Prosper, Harrison; Veeraraghavan, Venkatesh; Weinberg, Marc; Baarmand, Marc M; Hohlmann, Marcus; Kalakhety, Himali; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Kurt, Pelin; Moon, Dong Ho; O'Brien, Christine; Sandoval Gonzalez, Irving Daniel; Silkworth, Christopher; Turner, Paul; Varelas, Nikos; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Haytmyradov, Maksat; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Rahmat, Rahmat; Sen, Sercan; Tan, Ping; Tiras, Emrah; Wetzel, James; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bolognesi, Sara; Fehling, David; Gritsan, Andrei; Maksimovic, Petar; Martin, Christopher; Swartz, Morris; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Bruner, Christopher; Kenny III, Raymond Patrick; Malek, Magdalena; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Sekaric, Jadranka; Stringer, Robert; Wang, Quan; Wood, Jeffrey Scott; Chakaberia, Irakli; Ivanov, Andrew; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Saini, Lovedeep Kaur; Skhirtladze, Nikoloz; Svintradze, Irakli; Gronberg, Jeffrey; Lange, David; Rebassoo, Finn; Wright, Douglas; Baden, Drew; Belloni, Alberto; Calvert, Brian; Eno, Sarah Catherine; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G; Kolberg, Ted; Lu, Ying; Mignerey, Alice; Pedro, Kevin; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Barbieri, Richard; Bauer, Gerry; Busza, Wit; Cali, Ivan Amos; Chan, Matthew; Di Matteo, Leonardo; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Gulhan, Doga; Klute, Markus; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Ma, Teng; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Stephans, George; Sumorok, Konstanty; Velicanu, Dragos; Veverka, Jan; Wyslouch, Bolek; Yang, Mingming; Zanetti, Marco; Zhukova, Victoria; Dahmes, Bryan; Gude, Alexander; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Pastika, Nathaniel; Rusack, Roger; Singovsky, Alexander; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Claes, Daniel R; Dominguez, Aaron; Gonzalez Suarez, Rebeca; Keller, Jason; Knowlton, Dan; Kravchenko, Ilya; Lazo-Flores, Jose; Meier, Frank; Ratnikov, Fedor; Snow, Gregory R; Zvada, Marian; Dolen, James; Godshalk, Andrew; Iashvili, Ia; Kharchilava, Avto; Kumar, Ashish; Rappoccio, Salvatore; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Trocino, Daniele; Wang, Ren-Jie; Wood, Darien; Zhang, Jinzhong; Hahn, Kristan Allan; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Sung, Kevin; Velasco, Mayda; Won, Steven; Brinkerhoff, Andrew; Chan, Kwok Ming; Drozdetskiy, Alexey; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Lynch, Sean; Marinelli, Nancy; Musienko, Yuri; Pearson, Tessa; Planer, Michael; Ruchti, Randy; Smith, Geoffrey; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Antonelli, Louis; Brinson, Jessica; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Hart, Andrew; Hill, Christopher; Hughes, Richard; Kotov, Khristian; Ling, Ta-Yung; Luo, Wuming; Puigh, Darren; Rodenburg, Marissa; Winer, Brian L; Wolfe, Homer; Wulsin, Howard Wells; Driga, Olga; Elmer, Peter; Hardenbrook, Joshua; Hebda, Philip; Hunt, Adam; Koay, Sue Ann; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Brownson, Eric; Malik, Sudhir; Mendez, Hector; Ramirez Vargas, Juan Eduardo; Barnes, Virgil E; Benedetti, Daniele; Bortoletto, Daniela; De Mattia, Marco; Gutay, Laszlo; Hu, Zhen; Jha, Manoj; Jones, Matthew; Jung, Kurt; Kress, Matthew; Leonardo, Nuno; Miller, David Harry; Neumeister, Norbert; Radburn-Smith, Benjamin Charles; Shi, Xin; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Wang, Fuqiang; Xie, Wei; Xu, Lingshan; Zablocki, Jakub; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Ecklund, Karl Matthew; Geurts, Frank JM; Li, Wei; Michlin, Benjamin; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Garcia-Bellido, Aran; Goldenzweig, Pablo; Han, Jiyeon; Harel, Amnon; Khukhunaishvili, Aleko; Korjenevski, Sergey; Petrillo, Gianluca; Vishnevskiy, Dmitry; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Mesropian, Christina; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Kaplan, Steven; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Salur, Sevil; Schnetzer, Steve; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Rose, Keith; Spanier, Stefan; York, Andrew; Bouhali, Othmane; Castaneda Hernandez, Alfredo; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Krutelyov, Vyacheslav; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Rose, Anthony; Safonov, Alexei; Suarez, Indara; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kovitanggoon, Kittikul; Kunori, Shuichi; Lee, Sung Won; Libeiro, Terence; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Johns, Willard; Maguire, Charles; Mao, Yaxian; Melo, Andrew; Sharma, Monika; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Boutle, Sarah; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Lin, Chuanzhe; Neu, Christopher; Wood, John; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sturdy, Jared; Belknap, Donald; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Friis, Evan; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Lazaridis, Christos; Levine, Aaron; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ross, Ian; Sarangi, Tapas; Savin, Alexander; Smith, Wesley H; Taylor, Devin; Vuosalo, Carl; Woods, Nathaniel; Firlej, Miroslaw; Fiutowski, Tomasz; Idzik, Marek; Morawski, Piotr; Moron, Jakub; Oblakowska-Mucha, Agnieszka; Swientek, Krzysztof; Szumlak, Tomasz; Beaucourt, Leo; Chefdeville, Maximilien; Decamp, Daniel; Déléage, Nicolas; Ghez, Philippe; Lees, Jean-Pierre; Marchand, Jean François; Minard, Marie-Noelle; Pietrzyk, Boleslaw; Qian, Wenbin; Tisserand, Vincent; T'Jampens, Stephane; Tournefier, Edwige; Bifani, Simone; Farley, Nathanael; Griffith, Peter; Kenyon, Ian; Lazzeroni, Cristina; Mazurov, Alexander; McCarthy, James; Pescatore, Luca; Watson, Nigel; Williams, Matthew; Adinolfi, Marco; Benton, Jack; Brook, Nicholas; Cook, Andrew; Coombes, Matthew; Dalseno, Jeremy; Hampson, Thomas; Harnew, Samuel; Naik, Paras; Price, Eugenia; Prouve, Claire; Rademacker, Jonas; Richards, Sophie; Saunders, Daniel Martin; Skidmore, Nicola; Souza, Daniel; Velthuis, Jaap; Voong, David; Cojocariu, Lucian; Giubega, Lavinia-Helena; Grecu, Alexandru; Maciuc, Florin; Orlandea, Marius; Popovici, Bogdan; Stoica, Sabin; Straticiuc, Mihai; Barter, William; Bettler, Marc-Olivier; Cliff, Harry; Evans, Hannah Mary; Garra Tico, Jordi; Gibson, Valerie; Gregson, Sam; Haines, Susan; Jones, Christopher; Sirendi, Marek; Smith, Jackson; Ward, David; Wotton, Stephen; Wright, Simon; Xie, Yuehong; Pesen, Erhan; Alessio, Federico; Archilli, Flavio; Barschel, Colin; Benson, Sean; Buytaert, Jan; Campora Perez, Daniel; Castillo Garcia, Lucia; Cattaneo, Marco; Charpentier, Philippe; Cid Vidal, Xabier; Clemencic, Marco; Closier, Joel; Coco, Victor; Collins, Paula; Corti, Gloria; Couturier, Benjamin; D'Ambrosio, Carmelo; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Durante, Paolo; Ferro-Luzzi, Massimiliano; Forty, Roger; Frank, Markus; Frei, Christoph; Gaspar, Clara; Gligorov, V.V.; Granado Cardoso, Luis Alberto; Gys, Thierry; Haen, Christophe; He, Jibo; Head, Timothy; Jacobsson, Richard; Johnson, Daniel; Joram, Christian; Jost, Beat; Karacson, Matthias; Karbach, Moritz; Lacarrere, Daniel; Langhans, Benedikt; Lindner, Rolf; Linn, Christian; Lohn, Stefan; Mapelli, Alessandro; Matev, Rosen; Mathe, Zoltan; Neubert, Sebastian; Neufeld, Niko; Otto, Adam; Panman, Jacob; Pepe Altarelli, Monica; Rauschmayr, Nathalie; Rihl, Mariana; Roiser, Stefan; Ruf, Thomas; Schindler, Heinrich; Schmidt, Burkhard; Schopper, Andreas; Schwemmer, Rainer; Sridharan, Srikanth; Stagni, Federico; Subbiah, Vijay Kartik; Teubert, Frederic; Thomas, Eric; Tonelli, Diego; Trisovic, Ana; Ubeda Garcia, Mario; van Herwijnen, Eric; Wicht, Jean; Wyllie, Kenneth; Andreassen, Rolf; Davis, Adam; De Silva, Weeraddana; Meadows, Brian; Sokoloff, Michael; Sun, Liang; Todd, Jacob; Ajaltouni, Ziad; Baalouch, Marouen; Cogneras, Eric; Deschamps, Olivier; El Rifai, Ibrahim; Grabalosa Gándara, Marc; Henrard, Pierre; Hoballah, Mostafa; Lefèvre, Regis; Maratas, Jan; Monteil, Stephane; Niess, Valentin; Perret, Pascal; Milanes, Diego Alejandro; Dziurda, Agnieszka; Kucewicz, Wojciech; Lesiak, Tadeusz; Rachwal, Bartolomiej; Witek, Mariusz; Battista, Vincenzo; Bay, Aurelio; Blanc, Frédéric; Dorigo, Mirco; Dupertuis, Frederic; Fitzpatrick, Conor; Gianì, Sebastiana; Haefeli, Guido; Jaton, Pierre; Khurewathanakul, Chitsanu; Komarov, Ilya; La Thi, Viet Nga; Lopez-March, Neus; Märki, Raphael; Martinelli, Maurizio; Muster, Bastien; Nakada, Tatsuya; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Prisciandaro, Jessica; Puig Navarro, Albert; Rakotomiaramanana, Barinjaka; Rouvinet, Julien; Schneider, Olivier; Soomro, Fatima; Szczypka, Paul; Tobin, Mark; Tourneur, Stephane; Tran, Minh Tâm; Veneziano, Giovanni; Xu, Zhirui; Carson, Laurence; Clarke, Peter; Cowan, Greig; Eisenhardt, Stephan; Ferguson, Dianne; Lambert, Dean; Luo, Haofei; Morris, Adam Benjamin; Muheim, Franz; Needham, Matthew; Playfer, Stephen; Bencivenni, Giovanni; Campana, Pierluigi; De Simone, Patrizia; Lanfranchi, Gaia; Palutan, Matteo; Rama, Matteo; Sarti, Alessio; Sciascia, Barbara; Vazquez Gomez, Ricardo; Alexander, Michael; Beddow, John; Dean, Cameron Thomas; Eklund, Lars; Hynds, Daniel; Karodia, Sarah; Longstaff, Iain; Ogilvy, Stephen; Pappagallo, Marco; Sail, Paul; Skillicorn, Ian; Soler, Paul; Spradlin, Patrick; Bachmann, Sebastian; Bien, Alexander; Comerma-Montells, Albert; De Cian, Michel; Dordei, Francesca; Esen, Sevda; Färber, Christian; Gersabeck, Evelina; Grillo, Lucia; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Jaeger, Andreas; Kolpin, Michael; Kreplin, Katharina; Krocker, Georg; Leverington, Blake; Marks, Jörg; Meissner, Marco; Neuner, Max; Nikodem, Thomas; Seyfert, Paul; Stahl, Marian; Stahl, Sascha; Uwer, Ulrich; Vesterinen, Mika; Wandernoth, Sebastian; Wiedner, Dirk; Zhelezov, Alexey; Aquines Gutierrez, Osvaldo; Blouw, Johan; Britsch, Markward; Fontana, Marianna; Popov, Dmitry; Schmelling, Michael; Volyanskyy, Dmytro; Zavertyaev, Mikhail; Ciezarek, Gregory; Cunliffe, Samuel; Currie, Robert; Egede, Ulrik; Fol, Philip; Golutvin, Andrey; Hall, Samuel; McCann, Michael; Owen, Patrick; Patel, Mitesh; Petridis, Konstantin; Redi, Federico; Sepp, Indrek; Smith, Eluned; Sutcliffe, William; Websdale, David; Palano, Antimo; Carbone, Angelo; Falabella, Antonio; Galli, Domenico; Marconi, Umberto; Moggi, Niccolò; Mussini, Manuel; Perazzini, Stefano; Vagnoni, Vincenzo; Valenti, Giovanni; Zangoli, Maria; Bonivento, Walter; Cadeddu, Sandro; Cardini, Alessandro; Cogoni, Violetta; Contu, Andrea; Lai, Adriano; Liu, Bo; Manca, Giulia; Oldeman, Rudolf; Saitta, Biagio; Vacca, Claudia; Andreotti, Mirco; Baldini, Wander; Bozzi, Concezio; Calabrese, Roberto; Corvo, Marco; Fiore, Marco; Fiorini, Massimiliano; Luppi, Eleonora; Pappalardo, Luciano; Shapoval, Illya; Tellarini, Giulia; Tomassetti, Luca; Vecchi, Stefania; Anderlini, Lucio; Bizzeti, Andrea; Frosini, Maddalena; Graziani, Giacomo; Passaleva, Giovanni; Veltri, Michele; Cardinale, Roberta; Fontanelli, Flavio; Gambetta, Silvia; Patrignani, Claudia; Petrolini, Alessandro; Pistone, Alessandro; Fu, Jinlin; Geraci, Angelo; Neri, Nicola; Palombo, Fernando; Calvi, Marta; Cassina, Lorenzo; Gotti, Claudio; Khanji, Basem; Kucharczyk, Marcin; Matteuzzi, Clara; Amerio, Silvia; Collazuol, Gianmaria; Gallorini, Stefano; Gianelle, Alessio; Lucchesi, Donatella; Lupato, Anna; Morandin, Mauro; Rotondo, Marcello; Sestini, Lorenzo; Simi, Gabriele; Stroili, Roberto; Bedeschi, Franco; Cenci, Riccardo; Leo, Sabato; Marino, Pietro; Morello, Michael Joseph; Punzi, Giovanni; Stracka, Simone; Walsh, John; Alves Jr, Antonio Augusto; Auriemma, Giulio; Bocci, Valerio; Martellotti, Giuseppe; Penso, Gianni; Pinci, Davide; Santacesaria, Roberta; Satriano, Celestina; Sciubba, Adalberto; Carboni, Giovanni; Furfaro, Emiliano; Santovetti, Emanuele; Satta, Alessia; Dovbnya, Anatoliy; Kandybei, Sergii; Raniuk, Iurii; Okhrimenko, Oleksandr; Pugatch, Valery; Likhomanenko, Tatiana; Malinin, Alexander; Shevchenko, Vladimir; Ustyuzhanin, Andrey; Affolder, Anthony; Bowcock, Themistocles; Brown, Henry; Casse, Gianluigi; Donleavy, Stephanie; Dreimanis, Karlis; Farry, Stephen; Fay, Robert; Hennessy, Karol; Hutchcroft, David; Liles, Myfanwy; McSkelly, Ben; Patel, Girish; Price, Joseph David; Pritchard, Adrian; Rinnert, Kurt; Shears, Tara; Smith, Anthony; Appleby, Robert; Barlow, Roger; Bird, Thomas; Bjørnstad, Pål Marius; Borghi, Silvia; Brett, David; Brodzicka, Jolanta; Capriotti, Lorenzo; Chen, Shanzhen; De Capua, Stefano; Dujany, Giulio; Gersabeck, Marco; Harrison, Jonathan; Hombach, Christoph; Klaver, Suzanne; Lafferty, George; McNab, Andrew; Parkes, Christopher; Pearce, Alex; Reichert, Stefanie; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Smith, Mark; Adrover, Cosme; Akar, Simon; Aslanides, Elie; Cogan, Julien; Kanso, Walaa; Le Gac, Renaud; Leroy, Olivier; Mancinelli, Giampiero; Mordà, Alessandro; Perrin-Terrin, Mathieu; Serrano, Justine; Tsaregorodtsev, Andrei; Andrews, Jason; Hamilton, Brian; Jawahery, Abolhassan; Wimberley, Jack; Counts, Ian; Ilten, Philip; Williams, Mike; Filippov, Sergey; Gushchin, Evgeny; Kravchuk, Leonid; Belogurov, Sergey; Belyaev, Ivan; Egorychev, Victor; Golubkov, Dmitry; Kvaratskheliya, Tengiz; Machikhiliyan, Irina V; Polyakov, Ivan; Savrina, Darya; Semennikov, Alexander; Zhokhov, Anatoly; Batozskaya, Varvara; Klimaszewski, Konrad; Kurek, Krzysztof; Szczekowski, Marek; Ukleja, Artur; Wislicki, Wojciech; Aaij, Roel; Ali, Suvayu; David, Pieter; De Bruyn, Kristof; de Vries, Jacco; Farinelli, Chiara; Heijne, Veerle; Hulsbergen, Wouter; Jans, Eddy; Koppenburg, Patrick; Kozlinskiy, Alexandr; Merk, Marcel; Oggero, Serena; Pellegrino, Antonio; Snoek, Hella; Tsopelas, Panagiotis; Tuning, Niels; van Beuzekom, Martinus; van Leerdam, Jeroen; van Tilburg, Jeroen; Ketel, Tjeerd; Koopman, Rose; Lambert, Robert W; Martinez Santos, Diego; Raven, Gerhard; Schiller, Manuel; Syropoulos, Vasileios; Tolk, Siim; Bondar, Alexander; Eidelman, Semen; Krokovny, Pavel; Kudryavtsev, Vasily; Shekhtman, Lev; Vorobyev, Vitaly; Amhis, Yasmine; Barsuk, Sergey; Borsato, Martino; Kochebina, Olga; Lefrançois, Jacques; Machefert, Frederic; Martín Sánchez, Alexandra; Nicol, Michelle; Robbe, Patrick; Schune, Marie Helene; Teklishyn, Maksym; Vallier, Alexis; Viaud, Benoit; Wormser, Guy; Cheung, Shu-Faye; Derkach, Denis; Evans, Timothy; Gauld, Rhorry; Greening, Edward; Harnew, Neville; Hill, Donal; Hunt, Philip; Hussain, Nazim; Jalocha, Pawel; John, Malcolm; Lupton, Oliver; Malde, Sneha; Smith, Edmund; Stevenson, Scott; Thomas, Christopher; Topp-Joergensen, Stig; Torr, Nicholas; Wilkinson, Guy; Ben-Haim, Eli; Charles, Matthew; Coquereau, Samuel; David, Pascal; Del Buono, Luigi; Henry, Louis; Polci, Francesco; An, Liupan; Gao, Yuanning; Jing, Fanfan; Li, Yiming; Yang, Zhenwei; Yuan, Xuhao; Zhang, Yanxi; Zhong, Liang; Amato, Sandra; Carvalho Akiba, Kazuyoshi; De Paula, Leandro; Francisco, Oscar; Gandelman, Miriam; Hicheur, Adlène; Lopes, Jose; Martins Tostes, Danielle; Nasteva, Irina; Otalora Goicochea, Juan Martin; Polycarpo, Erica; Potterat, Cédric; Rangel, Murilo; Salustino Guimaraes, Valdir; Souza De Paula, Bruno; Vieira, Daniel; Bediaga, Ignacio; De Miranda, Jussara; dos Reis, Alberto; Ferreira Rodrigues, Fernando; Gomes, Alvaro; Massafferri, André; Rodrigues, Ana Barbara; Baesso, Clarissa; Cruz Torres, Melissa Maria; Göbel, Carla; Molina Rodriguez, Josue; Grünberg, Oliver; Heß, Miriam; Voß, Christian; Waldi, Roland; Easo, Sajan; Nandakumar, Raja; Papanestis, Antonios; Ricciardi, Stefania; Wilson, Fergus; Artamonov, Alexander; Belous, Konstantin; Dzhelyadin, Rustem; Guz, Yury; Novoselov, Alexey; Obraztsov, Vladimir; Popov, Alexander; Romanovsky, Vladimir; Shapkin, Mikhail; Stenyakin, Oleg; Yushchenko, Oleg; Berezhnoy, Alexander; Korolev, Mikhail; Leflat, Alexander; Nikitin, Nikolay; Alkhazov, Georgy; Bondar, Nikolay; Dzyuba, Alexey; Maev, Oleg; Sagidova, Naylya; Shcheglov, Yury; Vorobyev, Alexey; Artuso, Marina; Blusk, Steven; Borgia, Alessandra; Britton, Thomas; Ely, Scott; Gandini, Paolo; Garofoli, Justin; Gui, Bin; Hadjivasiliou, Christos; Jurik, Nathan; Kelsey, Matthew; Mountain, Raymond; Pal, Bilas Kanti; Skwarnicki, Tomasz; Stone, Sheldon; Wang, Jianchun; Xing, Zhou; Zhang, Liming; Albrecht, Johannes; Brambach, Tobias; Cauet, Christophe; Deckenhoff, Mirko; Eitschberger, Ulrich; Ekelhof, Robert; Gavardi, Laura; Kruse, Florian; Meier, Frank; Niet, Ramon; Parkinson, Christopher John; Schlupp, Maximilian; Shires, Alexander; Spaan, Bernhard; Swientek, Stefan; Wishahi, Julian; Badalov, Alexey; Calvo Gomez, Miriam; Garrido, Lluis; Gascon, David; Graciani Diaz, Ricardo; Graugés, Eugeni; Marin Benito, Carla; Picatoste Olloqui, Eduardo; Rives Molina, Vincente; Ruiz, Hugo; Vilasis-Cardona, Xavier; Adeva, Bernardo; Alvarez Cartelle, Paula; Dosil Suárez, Alvaro; Fernandez Albor, Victor; Gallas Torreira, Abraham; García Pardiñas, Julián; Hernando Morata, Jose Angel; Plo Casasus, Maximo; Romero Vidal, Antonio; Saborido Silva, Juan Jose; Sanmartin Sedes, Brais; Santamarina Rios, Cibran; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vieites Diaz, Maria; McNulty, Ronan; Wallace, Ronan; Zhang, Wen Chao; Martinez Vidal, Fernando; Oyanguren, Maria Arantza; Ruiz Valls, Pablo; Sanchez Mayordomo, Carlos; Onderwater, Gerco; Wilschut, Hans; Back, John; Blake, Thomas; Craik, Daniel Charles; Crocombe, Andrew Christopher; Dossett, David; Gershon, Timothy; Kreps, Michal; Langenbruch, Christoph; Latham, Thomas; O'Hanlon, Daniel Patrick; Pilař, Tomas; Poluektov, Anton; Reid, Matthew; Silva Coutinho, Rafael; Wallace, Charlotte; Whitehead, Mark; Anderson, Jonathan; Bernet, Roland; Bowen, Espen Eie; Bursche, Albert; Chiapolini, Nicola; Chrzaszcz, Marcin; Elsasser, Christian; Graverini, Elena; Lionetto, Federica; Lowdon, Peter; Müller, Katharina; Serra, Nicola; Steinkamp, Olaf; Storaci, Barbara; Straumann, Ulrich; Tresch, Marco; Vollhardt, Achim

    2015-05-13

    A joint measurement is presented of the branching fractions $B^0_s\\to\\mu^+\\mu^-$ and $B^0\\to\\mu^+\\mu^-$ in proton-proton collisions at the LHC by the CMS and LHCb experiments. The data samples were collected in 2011 at a centre-of-mass energy of 7 TeV, and in 2012 at 8 TeV. The combined analysis produces the first observation of the $B^0_s\\to\\mu^+\\mu^-$ decay, with a statistical significance exceeding six standard deviations, and the best measurement of its branching fraction so far, and three standard deviation evidence for the $B^0\\to\\mu^+\\mu^-$ decay. The measurements are statistically compatible with SM predictions and impose stringent constraints on several theories beyond the SM.

  7. Diffraction-analysis-based characterization of very fine gratings

    Science.gov (United States)

    Bischoff, Joerg; Truckenbrodt, Horst; Bauer, Joachim J.

    1997-09-01

    Fine gratings with spatial periods below one micron, either ruled mechanically or patterned holographically, play a key role as encoders in high precision translational or rotational coordinate or measuring machines. Besides, the fast in-line characterization of submicron patterns is a stringent demand in recent microelectronic technology. Thus, a rapid, destruction free and highly accurate measuring technique is required to ensure the quality during manufacturing and for final testing. We propose an optical method which was already successfully introduced in semiconductor industry. Here, the inverse scatter problem inherent in this diffraction based approach is overcome by sophisticated data analysis such as multivariate regression or neural networks. Shortly sketched, the procedure is as follows: certain diffraction efficiencies are measured with an optical angle resolved scatterometer and assigned to a number of profile parameters via data analysis (prediction). Before, the specific measuring model has to be calibrated. If the wavelength-to-period rate is well below unity, it is quite easy to gather enough diffraction orders. However, for gratings with spatial periods being smaller than the probing wavelength, merely the specular reflex will propagate for perpendicular incidence (zero order grating). Consequently, it is virtually impossible to perform a regression analysis. A proper mean to tackle this bottleneck is to record the zero-order reflex as a function of the incident angle. In this paper, the measurement of submicron gratings is discussed with the examples of 0.8, 1.0 and 1.4 micron period resist gratings on silicon, etched silicon oxide on silicon (same periods) and a 512 nm pitch chromium grating on quartz. Using a He-Ne laser with 633 nm wavelength and measuring the direct reflex in both linear polarizations, it is shown that even submicron patterning processes can be monitored and the resulting profiles with linewidths below a half micron can be

  8. NASA's Aeroacoustic Tools and Methods for Analysis of Aircraft Noise

    Science.gov (United States)

    Rizzi, Stephen A.; Lopes, Leonard V.; Burley, Casey L.

    2015-01-01

    Aircraft community noise is a significant concern due to continued growth in air traffic, increasingly stringent environmental goals, and operational limitations imposed by airport authorities. The ability to quantify aircraft noise at the source and ultimately at observers is required to develop low noise aircraft designs and flight procedures. Predicting noise at the source, accounting for scattering and propagation through the atmosphere to the observer, and assessing the perception and impact on a community requires physics-based aeroacoustics tools. Along with the analyses for aero-performance, weights and fuel burn, these tools can provide the acoustic component for aircraft MDAO (Multidisciplinary Design Analysis and Optimization). Over the last decade significant progress has been made in advancing the aeroacoustic tools such that acoustic analyses can now be performed during the design process. One major and enabling advance has been the development of the system noise framework known as Aircraft NOise Prediction Program2 (ANOPP2). ANOPP2 is NASA's aeroacoustic toolset and is designed to facilitate the combination of acoustic approaches of varying fidelity for the analysis of noise from conventional and unconventional aircraft. The toolset includes a framework that integrates noise prediction and propagation methods into a unified system for use within general aircraft analysis software. This includes acoustic analyses, signal processing and interfaces that allow for the assessment of perception of noise on a community. ANOPP2's capability to incorporate medium fidelity shielding predictions and wind tunnel experiments into a design environment is presented. An assessment of noise from a conventional and Hybrid Wing Body (HWB) aircraft using medium fidelity scattering methods combined with noise measurements from a model-scale HWB recently placed in NASA's 14x22 wind tunnel are presented. The results are in the form of community noise metrics and

  9. COLD FLOW ANALYSIS ON INTERNAL COMBUSTION ENGINE WITH DIFFERENT PISTON BOWL CONFIGURATIONS

    Directory of Open Access Journals (Sweden)

    N. A. MOHAMAD SHAFIE

    2017-04-01

    Full Text Available Development of engine in automotive industry is deemed critical in order to fulfil demands by passengers and also due to pressure bring forward by the fact of stringent government law for protecting noise and air quality. In order to improve engine quality, understanding on flow properties in engine cylinder is of major importance because flow condition significantly influences engine efficiency. Capabilities in providing optimum flow conditions which include high discharge coefficient, optimum swirl ratio, and optimum tumble ratio in respective engine can result in enhancement of engine power and comfort, along with reduction of fuel consumption, exhaust emission and noise. This research aims to investigate the effect of different piston bowl configurations on in-cylinder flow characteristics. Cold flow simulation is used to compare incylinder flow for engine with three different piston bowls during intake stroke and compression stroke. Simulation analysis represents the flow properties in term of swirl ratio and tumble ratio. Result computed from this analysis shows that piston bowl geometry has little influence on in-cylinder flow during intake stroke. However, piston bowls configurations inflicted significant effect on flow during compression stroke especially near top-dead-centre. This analysis defined that at the end of compression stroke, engine model with toroidal shape piston give 34.8% improvement in term of swirl ratio and 7% improvement of tumble ratio value compared to original piston bowl shapes.

  10. Pathway analysis for genome-wide association study of lung cancer in Han Chinese population.

    Directory of Open Access Journals (Sweden)

    Ruyang Zhang

    Full Text Available Genome-wide association studies (GWAS have identified a number of genetic variants associated with lung cancer risk. However, these loci explain only a small fraction of lung cancer hereditability and other variants with weak effect may be lost in the GWAS approach due to the stringent significance level after multiple comparison correction. In this study, in order to identify important pathways involving the lung carcinogenesis, we performed a two-stage pathway analysis in GWAS of lung cancer in Han Chinese using gene set enrichment analysis (GSEA method. Predefined pathways by BioCarta and KEGG databases were systematically evaluated on Nanjing study (Discovery stage: 1,473 cases and 1,962 controls and the suggestive pathways were further to be validated in Beijing study (Replication stage: 858 cases and 1,115 controls. We found that four pathways (achPathway, metPathway, At1rPathway and rac1Pathway were consistently significant in both studies and the P values for combined dataset were 0.012, 0.010, 0.022 and 0.005 respectively. These results were stable after sensitivity analysis based on gene definition and gene overlaps between pathways. These findings may provide new insights into the etiology of lung cancer.

  11. High frequency analysis of a plate carrying a concentrated nonlinear spring-mass system

    Science.gov (United States)

    Culver, Dean; Dowell, Earl

    2016-09-01

    Examining the behavior of dynamical systems with many degrees of freedom undergoing random excitation at high frequency often requires substantial computation. These requirements are even more stringent for nonlinear systems. One approach for describing linear systems, Asymptotic Modal Analysis (AMA), has been extended to nonlinear systems in this paper. A prototypical system, namely a thin plate carrying a concentrated hardening cubic spring-mass, is explored. The study focuses on the response of three principal variables to random, frequency-bounded excitation: the displacement of the mounting location of the discrete spring-mass, the relative displacement of the discrete mass to this mounting location, and the absolute displacement of the discrete mass. The results indicate that extending AMA to nonlinear systems for input frequency bands containing a large number of modes is feasible. Several advantageous properties of nonlinear AMA are found, and an additional reduced frequency-domain modal method, Dominance-Reduced Classical Modal Analysis (DRCMA), is proposed that is intermediate in accuracy and the cost of computation between AMA and Classical Modal Analysis (CMA).

  12. The potential of targeted antibody prophylaxis in SARS outbreak control: a mathematic analysis

    NARCIS (Netherlands)

    Bogaards, Johannes Antonie; Putter, Hein; Jan Weverling, Gerrit; ter Meulen, Jan; Goudsmit, Jaap

    2007-01-01

    BACKGROUND: Severe acute respiratory syndrome (SARS) coronavirus-like viruses continue to circulate in animal reservoirs. If new mutants of SARS coronavirus do initiate another epidemic, administration of prophylactic antibodies to risk groups may supplement the stringent isolation procedures that

  13. Analysis of cosmic microwave background radiation in the presence of Lorentz violation

    OpenAIRE

    Mewes, Matthew

    2007-01-01

    We examine the effects Lorentz violation on observations of cosmic microwave background radiation. In particular, we focus on changes in polarization caused by vacuum birefringence. We place stringent constraints on previously untested violations.

  14. Environmental Life Cycle Assessment and Cost Analysis of Bath, NY Wastewater Treatment Plant: Potential Upgrade Implications

    Science.gov (United States)

    Many communities across the U.S. are required to upgrade wastewater treatment plants (WWTP) to meet increasingly stringent nutrient effluent standards. However, increased capital, energy and chemical requirements of upgrades create potential trade-offs between eutrophication pot...

  15. ABC and VED Analysis of the Pharmacy Store of a Tertiary Care Teaching, Research and Referral Healthcare Institute of India.

    Science.gov (United States)

    Devnani, M; Gupta, Ak; Nigah, R

    2010-04-01

    The ABC and VED (vital, essential, desirable) analysis of the pharmacy store of Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India, was conducted to identify the categories of items needing stringent management control. The annual consumption and expenditure incurred on each item of pharmacy for the year 2007-08 was analyzed and inventory control techniques, i.e. ABC, VED and ABC-VED matrix analysis, were applied. The drug formulary of the pharmacy consisted of 421 items. The total annual drug expenditure (ADE) on items issued in 2007-08 was Rs. 40,012,612. ABC analysis revealed 13.78%, 21.85% and 64.37% items as A, B and C category items, respectively, accounting for 69.97%, 19.95% and 10.08% of ADE of the pharmacy. VED analysis showed 12.11%, 59.38% and 28.51% items as V, E, and D category items, respectively, accounting for 17.14%, 72.38% and 10.48% of ADE of the pharmacy. On ABC-VED matrix analysis, 22.09%, 54.63% and 23.28% items were found to be category I, II and III items, respectively, accounting for 74.21%, 22.23% and 3.56% of ADE of the pharmacy. The ABC and VED techniques need to be adopted as a routine practice for optimal use of resources and elimination of out-of-stock situations in the hospital pharmacy.

  16. High colloidal stability of gold nanorods coated with a peptide-ethylene glycol: Analysis by cyanide-mediated etching and nanoparticle tracking analysis.

    Science.gov (United States)

    Free, Paul; Conger, Gao; Siji, Wu; Zhang, Jing Bo; Fernig, David G

    2016-10-01

    The stability of gold nanorods was assessed following coating with various charged or uncharged ligands, mostly peptides. Highly stable monodispersed gold nanorods were obtained by coating CTAB-stabilized gold nanorods with a pentapeptide with C-terminal ethylene glycol units (peptide-EG). UV-vis spectroscopy of these nanorods suspended in saline solutions indicated no signs of aggregation, and they were easily purified using size-exclusion chromatography. A more stringent measure of nanorod stability involved observing changes in the UV-vis absorbance of gold nanorods subjected to etching with cyanide. The λmax absorbance of peptide-EG coated nanorods red-shifted in etchant solution. The hypothesis that changes in the nanorod aspect ratio led to this red-shift was confirmed by TEM analysis, which showed pit formation along the transverse axis. The etching process was followed in solution using nanoparticle tracking analysis. The red-shift was shown to occur while the particles remained mono-dispersed, and so was not due to aggregation. Adding both etchant solution and peptide-EG to the nanorods was further shown to allow modulation of the Δλmax red-shift and increase the etchant resistance of peptide-EG nanorods. Thus, very stable gold nanorods can be produced using the peptide-EG coating approach and their optical properties modulated with etchant. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Instrumental analysis

    International Nuclear Information System (INIS)

    Kim, Seung Jae; Seo, Seong Gyu

    1995-03-01

    This textbook deals with instrumental analysis, which consists of nine chapters. It has Introduction of analysis chemistry, the process of analysis and types and form of the analysis, Electrochemistry on basic theory, potentiometry and conductometry, electromagnetic radiant rays and optical components on introduction and application, Ultraviolet rays and Visible spectrophotometry, Atomic absorption spectrophotometry on introduction, flame emission spectrometry and plasma emission spectrometry. The others like infrared spectrophotometry, X-rays spectrophotometry and mass spectrometry, chromatography and the other instrumental analysis like radiochemistry.

  18. Content Analysis

    Directory of Open Access Journals (Sweden)

    George Bedinelli Rossi

    2014-09-01

    Full Text Available This study introduces the various definitions and types of content analysis. This type of analysis historically presents itself as a quantitative approach to data analysis and currently shows up as a qualitative approach. The most common types are the conceptual and relational analysis. The latter receives influences of linguistic, cognitive and mental models and it is subdivided in affective extraction, analysis of proximity and cognitive mapping. Regarding the importance of this type of analysis, we have quantitative and qualitative character and the latter approach can be used to identify hypotheses, theoretical constructs or even models that can be tested by multivariate statistical techniques or even by experiments. 

  19. LC/MS/MS analysis of the endogenous dimethyltryptamine hallucinogens, their precursors, and major metabolites in rat pineal gland microdialysate.

    Science.gov (United States)

    Barker, Steven A; Borjigin, Jimo; Lomnicka, Izabela; Strassman, Rick

    2013-12-01

    We report a qualitative liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the simultaneous analysis of the three known N,N-dimethyltryptamine endogenous hallucinogens, their precursors and metabolites, as well as melatonin and its metabolic precursors. The method was characterized using artificial cerebrospinal fluid (aCSF) as the matrix and was subsequently applied to the analysis of rat brain pineal gland-aCSF microdialysate. The method describes the simultaneous analysis of 23 chemically diverse compounds plus a deuterated internal standard by direct injection, requiring no dilution or extraction of the samples. The results demonstrate that this is a simple, sensitive, specific and direct approach to the qualitative analysis of these compounds in this matrix. The protocol also employs stringent MS confirmatory criteria for the detection and confirmation of the compounds examined, including exact mass measurements. The excellent limits of detection and broad scope make it a valuable research tool for examining the endogenous hallucinogen pathways in the central nervous system. We report here, for the first time, the presence of N,N-dimethyltryptamine in pineal gland microdialysate obtained from the rat. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Sensitivity analysis

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003741.htm Sensitivity analysis To use the sharing features on this page, please enable JavaScript. Sensitivity analysis determines the effectiveness of antibiotics against microorganisms (germs) ...

  1. Real analysis

    CERN Document Server

    McShane, Edward James

    2013-01-01

    This text surveys practical elements of real function theory, general topology, and functional analysis. Discusses the maximality principle, the notion of convergence, the Lebesgue-Stieltjes integral, function spaces and harmonic analysis. Includes exercises. 1959 edition.

  2. Strategic analysis

    OpenAIRE

    Bartuňková, Alena

    2011-01-01

    The goal of the master thesis is to conduct a strategic analysis of the Czech Export Bank. The work is divided in two parts, a theoretically methodological and practical part. Within theoretical part there is identified strategy by different approaches and there are described the procedures for strategic analysis. Findings from the theoretically methodological part are applied in the practical part and subsequently are used in the strategic analysis. The external analysis is characterized by ...

  3. A high quality Arabidopsis transcriptome for accurate transcript-level analysis of alternative splicing

    KAUST Repository

    Zhang, Runxuan

    2017-04-05

    Alternative splicing generates multiple transcript and protein isoforms from the same gene and thus is important in gene expression regulation. To date, RNA-sequencing (RNA-seq) is the standard method for quantifying changes in alternative splicing on a genome-wide scale. Understanding the current limitations of RNA-seq is crucial for reliable analysis and the lack of high quality, comprehensive transcriptomes for most species, including model organisms such as Arabidopsis, is a major constraint in accurate quantification of transcript isoforms. To address this, we designed a novel pipeline with stringent filters and assembled a comprehensive Reference Transcript Dataset for Arabidopsis (AtRTD2) containing 82,190 non-redundant transcripts from 34 212 genes. Extensive experimental validation showed that AtRTD2 and its modified version, AtRTD2-QUASI, for use in Quantification of Alternatively Spliced Isoforms, outperform other available transcriptomes in RNA-seq analysis. This strategy can be implemented in other species to build a pipeline for transcript-level expression and alternative splicing analyses.

  4. Researchers’ perceptions of ethical challenges in cluster randomized trials: a qualitative analysis

    Directory of Open Access Journals (Sweden)

    McRae Andrew D

    2013-01-01

    Full Text Available Abstract Background Cluster randomized trials (CRTs pose ethical challenges for investigators and ethics committees. This study describes the views and experiences of CRT researchers with respect to: (1 ethical challenges in CRTs; (2 the ethics review process for CRTs; and (3 the need for comprehensive ethics guidelines for CRTs. Methods Descriptive qualitative analysis of interviews conducted with a purposive sample of 20 experienced CRT researchers. Results Informants expressed concern over the potential for bias that may result from requirements to obtain informed consent from research participants in CRTs. Informants suggested that the need for informed consent ought to be related to the type of intervention under study in a CRT. Informants rarely expressed concern regarding risks to research participants in CRTs, other than risks to privacy. Important issues identified in the research ethics literature, including fair subject selection and other justice issues, were not mentioned by informants. The ethics review process has had positive and negative impacts on CRT conduct. Informants stated that variability in ethics review between jurisdictions, and increasingly stringent ethics review in recent years, have hampered their ability to conduct CRTs. Many informants said that comprehensive ethics guidelines for CRTs would be helpful to researchers and research ethics committees. Conclusions Informants identified key ethical challenges in the conduct of CRTs, specifically relating to identifying subjects, seeking informed consent, and the use of gatekeepers. These data have since been used to identify topics for in-depth ethical analysis and to guide the development of comprehensive ethics guidelines for CRTs.

  5. The analysis of animal faeces as a tool to monitor antibiotic usage.

    Science.gov (United States)

    Berendsen, Bjorn J A; Wegh, Robin S; Memelink, Joost; Zuidema, Tina; Stolker, Linda A M

    2015-01-01

    The analysis of antibiotics in animal faeces is important to obtain more insight in the possible formation of bacterial resistance in the animals׳ gut, to learn about the dissemination of antibiotics to the environment, to monitor trends in antibiotic usage and to detect the illegal and off-label use of antibiotics. To facilitate these studies a comprehensive method for the analysis of trace levels of 44 antibiotic compounds including tetracyclines, quinolones, macrolides and sulfonamides in animal faeces by liquid chromatography in combination with tandem mass spectrometric (LC-MS/MS) detection is reported. The method is fully validated according to European regulation and showed satisfactory quantitative performance according to the stringent criteria adopted, with the exception of some of the macrolide compounds, which can be analysed with somewhat high measurement uncertainty. A large survey was carried out monitoring swine and cattle faeces and the outcomes were striking. In 55% of the swines, originating from 80% of the swine farms and in 75% of the calves, originating from 95% of the cattle farms, antibiotics were detected. Oxytetracycline, doxycycline and sulfadiazine were the most detected antibiotics, followed by tetracycline, flumequine, lincomycin and tylosin. Over 34% of the faeces samples contained two or more different antibiotics with a maximum of eight. Possible explanations for these findings are given and the effects are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Analytical Kinematics and Coupled Vibrations Analysis of Mechanical System Operated by Solar Array Drive Assembly

    Science.gov (United States)

    Sattar, M.; Wei, C.; Jalali, A.; Sattar, R.

    2017-07-01

    To address the impact of solar array (SA) anomalies and vibrations on performance of precision space-based operations, it is important to complete its accurate jitter analysis. This work provides mathematical modelling scheme to approximate kinematics and coupled micro disturbance dynamics of rigid load supported and operated by solar array drive assembly (SADA). SADA employed in analysis provides a step wave excitation torque to activate the system. Analytical investigations into kinematics is accomplished by using generalized linear and Euler angle coordinates, applying multi-body dynamics concepts and transformations principles. Theoretical model is extended, to develop equations of motion (EoM), through energy method (Lagrange equation). The main emphasis is to research coupled frequency response by determining energies dissipated and observing dynamic behaviour of internal vibratory systems of SADA. The disturbance model captures discrete active harmonics of SADA, natural modes and vibration amplifications caused by interactions between active harmonics and structural modes of mechanical assembly. The proposed methodology can help to predict true micro disturbance nature of SADA operating rigid load. Moreover, performance outputs may be compared against actual mission requirements to assess precise spacecraft controller design to meet next space generation stringent accuracy goals.

  7. High-resolution sampling and analysis of ambient particulate matter in the Pearl River Delta region of southern China: source apportionment and health risk implications

    Science.gov (United States)

    Zhou, Shengzhen; Davy, Perry K.; Huang, Minjuan; Duan, Jingbo; Wang, Xuemei; Fan, Qi; Chang, Ming; Liu, Yiming; Chen, Weihua; Xie, Shanju; Ancelet, Travis; Trompetter, William J.

    2018-02-01

    Hazardous air pollutants, such as trace elements in particulate matter (PM), are known or highly suspected to cause detrimental effects on human health. To understand the sources and associated risks of PM to human health, hourly time-integrated major trace elements in size-segregated coarse (PM2.5-10) and fine (PM2.5) particulate matter were collected at the industrial city of Foshan in the Pearl River Delta region, China. Receptor modeling of the data set by positive matrix factorization (PMF) was used to identify six sources contributing to PM2.5 and PM10 concentrations at the site. Dominant sources included industrial coal combustion, secondary inorganic aerosol, motor vehicles and construction dust along with two intermittent sources (biomass combustion and marine aerosol). The biomass combustion source was found to be a significant contributor to peak PM2.5 episodes along with motor vehicles and industrial coal combustion. Conditional probability function (CPF) analysis was applied to estimate the source locations using the PMF-resolved source contribution coupled with the surface wind direction data. Health exposure risk of hazardous trace elements (Pb, As, Si, Cr, Mn and Ni) and source-specific values were estimated. The total hazard quotient (HQ) of PM2.5 was 2.09, higher than the acceptable limit (HQ = 1). The total carcinogenic risk (CR) was 3.37 × 10-3 for PM2.5, which was 3 times higher than the least stringent limit (1.0 × 10-4). Among the selected trace elements, As and Pb posed the highest non-carcinogenic and carcinogenic risks to human health, respectively. In addition, our results show that the industrial coal combustion source is the dominant non-carcinogenic and carcinogenic risk contributor, highlighting the need for stringent control of this source. This study provides new insight for policy makers to prioritize sources in air quality management and health risk reduction.

  8. Fourier analysis

    CERN Document Server

    Stade, Eric

    2005-01-01

    A reader-friendly, systematic introduction to Fourier analysis Rich in both theory and application, Fourier Analysis presents a unique and thorough approach to a key topic in advanced calculus. This pioneering resource tells the full story of Fourier analysis, including its history and its impact on the development of modern mathematical analysis, and also discusses essential concepts and today's applications. Written at a rigorous level, yet in an engaging style that does not dilute the material, Fourier Analysis brings two profound aspects of the discipline to the forefront: the wealth of ap

  9. Functional analysis

    CERN Document Server

    Kantorovich, L V

    1982-01-01

    Functional Analysis examines trends in functional analysis as a mathematical discipline and the ever-increasing role played by its techniques in applications. The theory of topological vector spaces is emphasized, along with the applications of functional analysis to applied analysis. Some topics of functional analysis connected with applications to mathematical economics and control theory are also discussed. Comprised of 18 chapters, this book begins with an introduction to the elements of the theory of topological spaces, the theory of metric spaces, and the theory of abstract measure space

  10. Análise das propriedades psicométricas da versão brasileira da escala tampa de cinesiofobia Analysis of the psychometric properties of the Brazilian version the tampa scale for kinesiophobia

    Directory of Open Access Journals (Sweden)

    Fabiano Botelho Siqueira

    2007-01-01

    Full Text Available O objetivo deste estudo foi examinar as propriedades psicométricas da Tampa Scale for Kinesiophobia, que foi traduzida e adaptada, seguindo metodologia recomendada. A versão adaptada, Escala Tampa para Cinesiofobia (ETC, foi aplicada em 50 indivíduos com dor lombar crônica (DLC não específica. A análise de Rasch revelou um coeficiente de fidedignidade de 0,95 para os itens da ETC, indicando excelente validade de construto. Para os indivíduos, o coeficiente foi de 0,80, demonstrando um padrão estável de respostas. O índice de separação dos indivíduos foi de 2,0 e de 4,5 para os itens, demonstrando que pacientes foram divididos em dois níveis de cinesiofobia e os itens em cinco níveis. Foram detectados dois itens erráticos, cuja porcentagem foi superior aos 5% permitidos pelo modelo estatístico. Esses resultados indicam uma necessidade de modificação, substituição ou exclusão desses itens para garantir que o instrumento avalie um construto unidimensional. Por outro lado, a presença de itens muito difíceis sugere que a ECT pode ser administrada em indivíduos com níveis mais altos de cinesiofobia. Esses achados indicam que a ETC apresenta potencial de aplicabilidade clínica significativo para indivíduos com DLC, porém, é preciso ter cautela na interpretação dos resultados, principalmente nas respostas aos itens considerados erráticos.The objective of this study was to examine psychometric properties of the Tampa Scale for Kinesiophobia, which was translated and adjusted according to recommended methodology. The adjusted version, the Escala Tampa para Cinesiofobia (ETC, was applied to 50 subjects with non-specific chronic lumbar pain (CLP. The Rasch analysis disclosed a reliability coefficient of 0.95 for ETC items, suggesting excellent construct validity. For the subjects, this coefficient was 0.80, showing a steady answer pattern. Subjects separation rates were 2.0 and 4.5 for the items, showing that patients were

  11. A comparison of different regulatory approaches, analysis of the relative benefits of command and control, reflexive law and social licensing in ensuring oil industry compliance with environmentally sustainable practices and obligations

    Science.gov (United States)

    Ghanaati, Sahar

    This paper explores the relative benefits of command and control, reflexive law and social licensing in ensuring oil industry compliance with environmentally sustainable practices and obligations. Recognizing why oil sands and their development are significant, the background and development are reviewed first, and then the focus is shifted to look at its economics including the benefits, uncertainties and environmental costs of development. This paper examines how lawmakers in Canada have failed to meet their respective obligation. Drawing on environmental provisions, case law and legal scholars’ articles, books and reports, this paper examines the very problematic issue of oil sands regulation. It proposes to provide an in depth analysis of each regulatory forms and their application to the oil sands. It concludes that in order to solve the oil sands regulation challenges, a collaborative stringent enforcement of regulation from both federal and provincial governments, oil industry and public Pressure is required.

  12. Effectiveness of stringent decontamination of computer input devices in the era of electronic medical records and bedside computing: a randomized controlled trial.

    Science.gov (United States)

    Codish, Shlomi; Toledano, Ronen; Novack, Victor; Sherf, Michael; Borer, Abraham

    2015-06-01

    Bedside computing may lead to increased hospital-acquired infections mediated by computer input devices handled immediately after patient contact. We compared 2 decontamination methods in 2 types of wards. We found high baseline contamination rates, which decreased following decontamination, but the rates remained unacceptably high. Decontamination was more effective in intensive care units compared with medical wards and when using alcohol-based impregnated wipes compared with quaternary ammonium-based impregnated wipes. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  13. Impact of a More Stringent Blood Lead Level Recommendation for Children (Ages 1-5): Vulnerabilities Related to Housing, Food Security, Vitamins, and Environmental Toxicants

    Science.gov (United States)

    The adverse health effects of lead (Pb) exposure in young children are well known. Non-Hispanic black children historically have higher blood Pb levels (BLL) compared to Mexican-Americans and non- Hispanic white children (CDC-MMWR). In the past, BLL tests below 10 µg/dL m...

  14. The central dynamics of M3, M13, and M92: stringent limits on the masses of intermediate-mass black holes

    Science.gov (United States)

    Kamann, S.; Wisotzki, L.; Roth, M. M.; Gerssen, J.; Husser, T.-O.; Sandin, C.; Weilbacher, P.

    2014-06-01

    We used the PMAS integral field spectrograph to obtain large sets of radial velocities in the central regions of three northern Galactic globular clusters: M3, M13, and M92. By applying the novel technique of crowded field 3D spectroscopy, we measured radial velocities for about 80 stars within the central ~10″ of each cluster. These are by far the largest spectroscopic datasets obtained in the innermost parts of these clusters up to now. To obtain kinematical data across the whole extent of the clusters, we complement our data with measurements available in the literature. We combine our velocity measurements with surface brightness profiles to analyse the internal dynamics of each cluster using spherical Jeans models, and investigate whether our data provide evidence for an intermediate-mass black hole in any of the clusters. The surface brightness profiles reveal that all three clusters are consistent with a core profile, although shallow cusps cannot be excluded. We find that spherical Jeans models with a constant mass-to-light ratio provide a good overall representation of the kinematical data. A massive black hole is required in none of the three clusters to explain the observed kinematics. Our 1σ (3σ) upper limits are 5300 M⊙ (12 000 M⊙) for M3, 8600 M⊙ (13 000 M⊙) for M13, and 980 M⊙ (2700 M⊙) for M92. A puzzling circumstance is the existence of several potential high velocity stars in M3 and M13, as their presence can account for the majority of the discrepancies that we find in our mass limits compared to M92. Based on observations collected at the Centro Astronómico Hispano-Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).Appendices are available in electronic form at http://www.aanda.orgTables D.1 to D.6 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/566/A58

  15. Pressure broadening of the electric dipole and Raman lines of CO2 by argon: Stringent test of the classical impact theory at different temperatures on a benchmark system

    International Nuclear Information System (INIS)

    Ivanov, Sergey V.; Buzykin, Oleg G.

    2016-01-01

    A classical approach is applied to calculate pressure broadening coefficients of CO 2 vibration–rotational spectral lines perturbed by Ar. Three types of spectra are examined: electric dipole (infrared) absorption; isotropic and anisotropic Raman Q branches. Simple and explicit formulae of the classical impact theory are used along with exact 3D Hamilton equations for CO 2 –Ar molecular motion. The calculations utilize vibrationally independent most accurate ab initio potential energy surface (PES) of Hutson et al. expanded in Legendre polynomial series up to l max = 24. New improved algorithm of classical rotational frequency selection is applied. The dependences of CO 2 half-widths on rotational quantum number J up to J=100 are computed for the temperatures between 77 and 765 K and compared with available experimental data as well as with the results of fully quantum dynamical calculations performed on the same PES. To make the picture complete, the predictions of two independent variants of the semi-classical Robert-Bonamy formalism for dipole absorption lines are included. This method. however, has demonstrated poor accuracy almost for all temperatures. On the contrary, classical broadening coefficients are in excellent agreement both with measurements and with quantum results at all temperatures. The classical impact theory in its present variant is capable to produce quickly and accurately the pressure broadening coefficients of spectral lines of linear molecules for any J value (including high Js) using full-dimensional ab initio - based PES in the cases where other computational methods are either extremely time consuming (like the quantum close coupling method) or give erroneous results (like semi-classical methods). - Highlights: • Classical and semi-classical Ar-broadening coefficients for CO 2 . • Infrared absorption and Raman isotropic and anisotropic lines of CO 2 . Low and high temperatures. • Application of very accurate potential energy surface for CO 2 –Ar interactions. • High accuracy of the classical impact theory. • Low accuracy of semi-classical Robert-Bonamy method.

  16. The g-factor of the electron bound in {sup 28}Si{sup 13+}. The most stringent test of bound-state quantum electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, Sven

    2012-09-06

    This thesis describes the ultra-precise determination of the g-factor of the electron bound to hydrogenlike {sup 28}Si{sup 13+}. The experiment is based on the simultaneous determination of the cyclotron- and Larmor frequency of a single ion, which is stored in a triple Penning-trap setup. The continuous Stern-Gerlach effect is used to couple the spin of the bound electron to the motional frequencies of the ion via a magnetic bottle, which allows the non-destructive determination of the spin state. To this end, a highly sensitive, cryogenic detection system was developed, which allowed the direct, non-destructive detection of the eigenfrequencies with the required precision. The development of a novel, phase sensitive detection technique finally allowed the determination of the g-factor with a relative accuracy of 4 . 10{sup -11}, which was previously inconceivable. The comparison of the hereby determined value with the value predicted by quantumelectrodynamics (QED) allows the verification of the validity of this fundamental theory under the extreme conditions of the strong binding potential of a highly charged ion. The exact agreement of theory and experiment is an impressive demonstration of the exactness of QED. The experimental possibilities created in this work will allow in the near future not only further tests of theory, but also the determination of the mass of the electron with a precision that exceeds the current literature value by more than an order of magnitude.

  17. Mexico’s Transition to a Net-Zero Emissions Energy System: Near Term Implications of Long Term Stringent Climate Targets

    DEFF Research Database (Denmark)

    Solano-Rodríguez, Baltazar; Pizarro Alonso, Amalia Rosa; Vaillancourt, Kathleen

    2018-01-01

    the economy of this sector, as well as the use of natural gas for electricity generation in order to reduce electricity prices in the short term. In 2016, nearly 80% of Mexico’s total electricity was generated by thermal power plants. While natural gas prices stay low, there might be a limited role...... for natural gas to act as a fuel bridge in this sector if the government is to pursue deep decarbonisation targets to 2050. There is a risk that over-investing in gas infrastructure may delay a transition to lower carbon sources, potentially leading to less cost-efficient pathways towards decarbonisation...... PV and wind); also, that decarbonisation paths post-2030 are largely dependent on the investment decisions made in the 2020s. It is therefore essential that Mexico’s energy planning decision-makers avoid a natural gas “lock-in” that would either cause carbon targets to be missed or risk leaving some...

  18. The Impact on IPO Performance of More Stringent Listing Rules with a Pre-listing Earnings Requirement: Evidence from Hong Kong

    OpenAIRE

    Wai-yan Cheng; Yan-leung Cheung; Yuen-ching Tse

    2005-01-01

    This study considers the impact of a change to listing rules covering IPO performance in the Hong Kong stock market. The change, introduced in 1994, imposed a three-year pre-listing earning requirement on new issues. The objective of this research is to screen out a subset of poor IPO performers. We find there is no significant difference in performance between IPOs before and after the regulatory change. We further divide our sample of IPOs registered before the regulatory change into two su...

  19. pOp6/LhGR: a stringently regulated and highly responsive dexamethasone-inducible gene expression system for tobacco

    Czech Academy of Sciences Publication Activity Database

    Šámalová, Markéta; Brzobohatý, Břetislav; Moore, Ian

    2005-01-01

    Roč. 41, - (2005), s. 919-935 ISSN 0960-7412 R&D Projects: GA AV ČR(CZ) IAA5004001; GA AV ČR(CZ) KSK5052113 Institutional research plan: CEZ:AV0Z50040507 Keywords : chemically inducible gene expression * cytokinin-biosynthetic gene ipt * tobacco Subject RIV: BO - Biophysics Impact factor: 6.969, year: 2005

  20. Phylogenetic analysis using parsimony and likelihood methods.

    Science.gov (United States)

    Yang, Z

    1996-02-01

    The assumptions underlying the maximum-parsimony (MP) method of phylogenetic tree reconstruction were intuitively examined by studying the way the method works. Computer simulations were performed to corroborate the intuitive examination. Parsimony appears to involve very stringent assumptions concerning the process of sequence evolution, such as constancy of substitution rates between nucleotides, constancy of rates across nucleotide sites, and equal branch lengths in the tree. For practical data analysis, the requirement of equal branch lengths means similar substitution rates among lineages (the existence of an approximate molecular clock), relatively long interior branches, and also few species in the data. However, a small amount of evolution is neither a necessary nor a sufficient requirement of the method. The difficulties involved in the application of current statistical estimation theory to tree reconstruction were discussed, and it was suggested that the approach proposed by Felsenstein (1981, J. Mol. Evol. 17: 368-376) for topology estimation, as well as its many variations and extensions, differs fundamentally from the maximum likelihood estimation of a conventional statistical parameter. Evidence was presented showing that the Felsenstein approach does not share the asymptotic efficiency of the maximum likelihood estimator of a statistical parameter. Computer simulations were performed to study the probability that MP recovers the true tree under a hierarchy of models of nucleotide substitution; its performance relative to the likelihood method was especially noted. The results appeared to support the intuitive examination of the assumptions underlying MP. When a simple model of nucleotide substitution was assumed to generate data, the probability that MP recovers the true topology could be as high as, or even higher than, that for the likelihood method. When the assumed model became more complex and realistic, e.g., when substitution rates were

  1. Rasches Wachstum, frühe Reifung und kurze Generationenzeit bei afrikanischen annuellen Fischen.

    Czech Academy of Sciences Publication Activity Database

    Blažek, Radim; Polačik, Matej; Reichard, Martin

    2017-01-01

    Roč. 49, č. 3 (2017), s. 131-141 ISSN 0179-4957 R&D Projects: GA ČR(CZ) GAP506/11/0112 Institutional support: RVO:68081766 Keywords : extreme life history * annual fish * explosive growth * rapid maturation * generation time * killifish * diapause * vertebrate * reaction norm * Savanna Subject RIV: EG - Zoology

  2. School Administrators' Beliefs that School Improvements Were Due to Formal School Registration: A Rasch Measurement

    Science.gov (United States)

    Witten, Harm; Waugh, Russell; Gray, Jan

    2012-01-01

    This paper presents the results of an investigation into the attitudes of School Administrators to the relationship between formal school registration and school improvement. It concerns a mandatory inspection-type registration process for all Non-Government Schools in Western Australia. Part of the aim of this registration process was to help…

  3. Using Rasch Measurement to Validate the Instrument of Students' Understanding of Models in Science (SUMS)

    Science.gov (United States)

    Wei, Silin; Liu, Xiufeng; Jia, Yuane

    2014-01-01

    Scientific models and modeling play an important role in science, and students' understanding of scientific models is essential for their understanding of scientific concepts. The measurement instrument of "Students' Understanding of Models in Science" (SUMS), developed by Treagust, Chittleborough & Mamiala ("International…

  4. An assessment model of historical thinking skills by means of the RASCH model

    Directory of Open Access Journals (Sweden)

    Ofianto Ofianto

    2015-06-01

    Full Text Available This study was conducted to produce a model and instruments of historical thinking skills in the history subject at the senior high school (SHS and to identify SHS students’ historical thinking skills. The study was conducted in two stages, namely model development and instrument development altogether with a small-scale tryout and a large-scale tryout. The test for each tryout consisted of six and five sub-test sets. Each test set contained 20 anchor items. The sample for each tryout comprised 1573 and 2613 testees. The data was analyzed by means of Partial Credit Model (PCM using the QUEST program. The overall tryout results indicate that, based on the criteria for an INFIT MNSQ mean of 0.1 and a standard deviation of 1.0, the tests fit the PCM. The reliability coefficients of the tests for the tryouts are moderately good; the Cronbach’s alpha coefficients are, respectively, 0.65 and 0.54. The lowest score of historical thinking skills is -.352 and the highest is +1.21 in an ideal range of -4.0 to +4.0. In overall, the testees’ scores are not satisfactory. Only 5.89% of the testees are above the expected median.

  5. Mixing Interviews and Rasch Modeling: Demonstrating a Procedure Used to Develop an Instrument That Measures Trust

    Science.gov (United States)

    David, Shannon L.; Hitchcock, John H.; Ragan, Brian; Brooks, Gordon; Starkey, Chad

    2018-01-01

    Developing psychometrically sound instruments can be difficult, especially if little is known about the constructs of interest. When constructs of interest are unclear, a mixed methods approach can be useful. Qualitative inquiry can be used to explore a construct's meaning in a way that informs item writing and allows the strengths of one analysis…

  6. Development of Objective Standard Setting Using Rasch Measurement Model in Malaysian Institution of Higher Learning

    Science.gov (United States)

    Khatimin, Nuraini; Aziz, Azrilah Abdul; Zaharim, Azami; Yasin, Siti Hanani Mat

    2013-01-01

    Measurement and evaluation of students' achievement are an important aspect to make sure that students really understand the course content and monitor students' achievement level. Performance is not only reflected from the numbers of high achievers of the students, but also on quality of the grade obtained; does the grade "A" truly…

  7. Item Construction Using Reflective, Formative, or Rasch Measurement Models: Implications for Group Work

    Science.gov (United States)

    Peterson, Christina Hamme; Gischlar, Karen L.; Peterson, N. Andrew

    2017-01-01

    Measures that accurately capture the phenomenon are critical to research and practice in group work. The vast majority of group-related measures were developed using the reflective measurement model rooted in classical test theory (CTT). Depending on the construct definition and the measure's purpose, the reflective model may not always be the…

  8. Using Rasch Modeling to Investigate a Learning Progression for Energy Ideas

    Science.gov (United States)

    Herrmann-Abell, Cari F.; DeBoer, George E.

    2016-01-01

    Energy is a core concept in the teaching of science. Therefore, it is important to know how students' thinking about energy develops so that elementary, middle, and high school students can be appropriately supported in their understanding of energy. This study tests the validity of a proposed theoretical model of students' growth of understanding…

  9. Implications of Rasch Calibrated Item Banks for Measurement of the Locally Planned Curriculum.

    Science.gov (United States)

    Hunt, Barbara

    Many problems are encountered by school districts regardless of size. State and federal involvement in education provides certain financial resources, but also makes demands for accountability. This creates conflicts between local program development and the requirements of state and federal regulations, and particularly complicates the…

  10. International Assessment: A Rasch Model and Teachers' Evaluation of TIMSS Science Achievement Items

    Science.gov (United States)

    Glynn, Shawn M.

    2012-01-01

    The Trends in International Mathematics and Science Study (TIMSS) is a comparative assessment of the achievement of students in many countries. In the present study, a rigorous independent evaluation was conducted of a representative sample of TIMSS science test items because item quality influences the validity of the scores used to inform…

  11. Modeling Local Item Dependence Due to Common Test Format with a Multidimensional Rasch Model

    Science.gov (United States)

    Baghaei, Purya; Aryadoust, Vahid

    2015-01-01

    Research shows that test method can exert a significant impact on test takers' performance and thereby contaminate test scores. We argue that common test method can exert the same effect as common stimuli and violate the conditional independence assumption of item response theory models because, in general, subsets of items which have a shared…

  12. Modeling Repeated Count Data : Some Extensions of the Rasch Poisson Counts Model

    NARCIS (Netherlands)

    van Duijn, M.A.J.; Jansen, Margo

    1995-01-01

    We consider data that can be summarized as an N X K table of counts-for example, test data obtained by administering K tests to N subjects. The cell entries y(ij) are assumed to be conditionally independent Poisson-distributed random variables, given the NK Poisson intensity parameters mu(ij). The

  13. Quality Control of an OSCE Using Generalizability Theory and Many-Faceted Rasch Measurement

    Science.gov (United States)

    Iramaneerat, Cherdsak; Yudkowsky, Rachel; Myford, Carol M.; Downing, Steven M.

    2008-01-01

    An Objective Structured Clinical Examination (OSCE) is an effective method for evaluating competencies. However, scores obtained from an OSCE are vulnerable to many potential measurement errors that cases, items, or standardized patients (SPs) can introduce. Monitoring these sources of errors is an important quality control mechanism to ensure…

  14. Adaptive mastery testing using the Rasch model and Bayesian sequential decision theory

    NARCIS (Netherlands)

    Glas, Cornelis A.W.; Vos, Hendrik J.

    1998-01-01

    A version of sequential mastery testing is studied in which response behavior is modeled by an item response theory (IRT) model. First, a general theoretical framework is sketched that is based on a combination of Bayesian sequential decision theory and item response theory. A discussion follows on

  15. Development and Psychometric Evaluation of the School Bullying Scales: A Rasch Measurement Approach

    Science.gov (United States)

    Cheng, Ying-Yao; Chen, Li-Ming; Liu, Kun-Shia; Chen, Yi-Ling

    2011-01-01

    The study aims to develop three school bullying scales--the Bully Scale, the Victim Scale, and the Witness Scale--to assess secondary school students' bullying behaviors, including physical bullying, verbal bullying, relational bullying, and cyber bullying. The items of the three scales were developed from viewpoints of bullies, victims, and…

  16. Using Rasch Modeling and Option Probability Curves to Diagnose Students' Misconceptions

    Science.gov (United States)

    Herrmann-Abell, Cari F.; DeBoer, George E.

    2016-01-01

    Understanding students' misconceptions and how they change is an essential part of supporting students in their science learning. This paper presents results from distractor-driven multiple-choice assessments that target students' misconceptions about energy. Over 20,000 elementary, middle and high school students from across the U.S. participated…

  17. The Variance of Rasch Ability Estimates from Partially-Known Item Parameters

    Science.gov (United States)

    1992-01-01

    8217!; Avail and/or Noet Speoial Partially Known Item Parameters Introduction It is common practice in applications of item response theory (IRT) to...Beckeley. CA 94720 Dr. Eugene Winograd Department of Pschology Emory Unwereemy Atlanta. GA 30322 Dr. Martin F. Wmkoft PERSEREC 99 Pacific, St., Suite 4356

  18. Developing a fluid intelligence scale through a combination of Rasch modeling and cognitive psychology.

    Science.gov (United States)

    Primi, Ricardo

    2014-09-01

    Ability testing has been criticized because understanding of the construct being assessed is incomplete and because the testing has not yet been satisfactorily improved in accordance with new knowledge from cognitive psychology. This article contributes to the solution of this problem through the application of item response theory and Susan Embretson's cognitive design system for test development in the development of a fluid intelligence scale. This study is based on findings from cognitive psychology; instead of focusing on the development of a test, it focuses on the definition of a variable for the creation of a criterion-referenced measure for fluid intelligence. A geometric matrix item bank with 26 items was analyzed with data from 2,797 undergraduate students. The main result was a criterion-referenced scale that was based on information from item features that were linked to cognitive components, such as storage capacity, goal management, and abstraction; this information was used to create the descriptions of selected levels of a fluid intelligence scale. The scale proposed that the levels of fluid intelligence range from the ability to solve problems containing a limited number of bits of information with obvious relationships through the ability to solve problems that involve abstract relationships under conditions that are confounded with an information overload and distraction by mixed noise. This scale can be employed in future research to provide interpretations for the measurements of the cognitive processes mastered and the types of difficulty experienced by examinees. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  19. Measuring Student Teachers' Practices and Beliefs about Teaching Mathematics Using the Rasch Model

    Science.gov (United States)

    Kaspersen, Eivind; Pepin, Birgit; Sikko, Svein Arne

    2017-01-01

    Several attempts have been made to measure and categorize beliefs and practices of mathematics teachers [Swan, M. 2006. "Designing and Using Research Instruments to Describe the Beliefs and Practices of Mathematics Teachers." "Research in Education" 75 (1): 58-70]. One of the reasons for measuring both beliefs and practices is…

  20. Penskalaan Butir Format Respons Pilihan dan Respons Bebas Berdasarkan Model Rasch dan Partial Credit

    Directory of Open Access Journals (Sweden)

    Eko Hariadi

    2007-06-01

    Full Text Available Penelitian melihat pengaruh jumlah parameter butir, kategori respons bebas (RB, pengaruh sampel terhadap akurasi estimasi parameter kemampuan untuk menghasilkan estimasi yang stabil dan pengaruh pembobotan butir RP dan butir RB terhadap kesalahan baku. Penelitian dalam dua tahap, simulasi menggunakan 30 kondisi dengan replikasi 50 dengan variabel panjang tes, jumlah kategori, dan jumlah parameter butir, dan analisis deskriptif, dilanjutkan penerapan penskalaan gabungan butir tipe respons pilihan (rp dan butir respons bebas (rb pada konstruksi tes elektronika yang terdiri 40 butir pilihan ganda dan 4 butir jawaban tersusun, 3 butir memiliki lima kategori jawaban dan 1 butir dengan 4 kategori jawaban, melibatkan 355 siswa. Hasil penelitian menunjukkan: ukuran sampel kurang berpengaruh pada root mean square error atau (RSME> dan korelasi antara 9 dengan 0, namun berpengaruh terhadap akurasi estimasi parameter butir pilihan ganda (/>/y,dan parameter butir respons tersusun (3^- Jumlah parameter butir berpengaruh terhadap parameter kemampuan, tetapi tidak berpengaruh terhadap akurasi dari b^, dan S„,. Estimasi dari parameter tingkat kesulitan butir jawaban tersusun tiga kategori lebih akurat daripada butir jawaban tersusun lima kategori. Estimasi tahan {robust untuk parameter kesulitan butir jawaban tersusun 5 kategori memerlukan sampel minimal 250 responden, sedangkan untuk butir respons tersusun 3 kategori memerlukan sampel minimal 100 responden. Estimasi parameter kemampuan dari skor total (0^^ tidak sama dengan rata-rata jumlah tbeta dari masing-masing subtes (0^ + 0CR. Theta dari tes yang dikalibrasi bersama-sama berbeda dengan theta dari total subtes yang dikalibrasi secara terpisah. Korelasi kemampuan yang mengunakan pembobotan dan kemampuan tanpa pembobotan mempunyai suatu rentang dari 0,988 sampai 0,948. Kata kunci: penyekaiaan, model rash dan partial credit.