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Sample records for rasch measurement model

  1. FIM measurement properties and Rasch model details.

    Science.gov (United States)

    Wright, B D; Linacre, J M; Smith, R M; Heinemann, A W; Granger, C V

    1997-12-01

    To summarize, we take issue with the criticisms of Dickson & Köhler for two main reasons: 1. Rasch analysis provides a model from which to approach the analysis of the FIM, an ordinal scale, as an interval scale. The existence of examples of items or individuals which do not fit the model does not disprove the overall efficacy of the model; and 2. the principal components analysis of FIM motor items as presented by Dickson & Köhler tends to undermine rather than support their argument. Their own analyses produce a single major factor explaining between 58.5 and 67.1% of the variance, depending upon the sample, with secondary factors explaining much less variance. Finally, analysis of item response, or latent trait, is a powerful method for understanding the meaning of a measure. However, it presumes that item scores are accurate. Another concern is that Dickson & Köhler do not address the issue of reliability of scoring the FIM items on which they report, a critical point in comparing results. The Uniform Data System for Medical Rehabilitation (UDSMRSM) expends extensive effort in the training of clinicians of subscribing facilities to score items accurately. This is followed up with a credentialing process. Phase 1 involves the testing of individual clinicians who are submitting data to determine if they have achieved mastery over the use of the FIM instrument. Phase 2 involves examining the data for outlying values. When Dickson & Köhler investigate more carefully the application of the Rasch model to their FIM data, they will discover that the results presented in their paper support rather than contradict their application of the Rasch model! This paper is typical of supposed refutations of Rasch model applications. Dickson & Köhler will find that idiosyncrasies in their data and misunderstandings of the Rasch model are the only basis for a claim to have disproven the relevance of the model to FIM data. The Rasch model is a mathematical theorem (like

  2. Understanding Rasch Measurement: Partial Credit Model and Pivot Anchoring.

    Science.gov (United States)

    Bode, Rita K.

    2001-01-01

    Describes the Rasch measurement partial credit model, what it is, how it differs from other Rasch models, and when and how to use it. Also describes the calibration of instruments with increasingly complex items. Explains pivot anchoring and illustrates its use and describes the effect of pivot anchoring on step calibrations, item hierarchy, and…

  3. 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

  4. Measurement of change in health status with Rasch models.

    Science.gov (United States)

    Anselmi, Pasquale; Vidotto, Giulio; Bettinardi, Ornella; Bertolotti, Giorgio

    2015-02-07

    The traditional approach to the measurement of change presents important drawbacks (no information at individual level, ordinal scores, variance of the measurement instrument across time points), which Rasch models overcome. The article aims to illustrate the features of the measurement of change with Rasch models. To illustrate the measurement of change using Rasch models, the quantitative data of a longitudinal study of heart-surgery patients (N = 98) were used. The scale "Perception of Positive Change" was used as an example of measurement instrument. All patients underwent cardiac rehabilitation, individual psychological intervention, and educational intervention. Nineteen patients also attended progressive muscle relaxation group trainings. The scale was administered before and after the interventions. Three Rasch approaches were used. Two separate analyses were run on the data from the two time points to test the invariance of the instrument. An analysis was run on the stacked data from both time points to measure change in a common frame of reference. Results of the latter analysis were compared with those of an analysis that removed the influence of local dependency on patient measures. Statistics t, χ(2) and F were used for comparing the patient and item measures estimated in the Rasch analyses (a-priori α = .05). Infit, Outfit, R and item Strata were used for investigating Rasch model fit, reliability, and validity of the instrument. Data of all 98 patients were included in the analyses. The instrument was reliable, valid, and substantively unidimensional (Infit, Outfit instrument occurred across the two time, which prevented the use of the two separate analyses to unambiguously measure change. Local dependency had a negligible effect on patient measures (p ≥ .8674). Thirteen patients improved, whereas 3 worsened. The patients who attended the relaxation group trainings did not report greater improvement than those who did not (p

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

    Science.gov (United States)

    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…

  6. Graphical Rasch models

    DEFF Research Database (Denmark)

    Kreiner, Svend; Christensen, Karl Bang

    Rasch models; Partial Credit models; Rating Scale models; Item bias; Differential item functioning; Local independence; Graphical models......Rasch models; Partial Credit models; Rating Scale models; Item bias; Differential item functioning; Local independence; Graphical models...

  7. Causal Rasch models.

    Science.gov (United States)

    Stenner, A Jackson; Fisher, William P; Stone, Mark H; Burdick, Donald S

    2013-01-01

    Rasch's unidimensional models for measurement show how to connect object measures (e.g., reader abilities), measurement mechanisms (e.g., machine-generated cloze reading items), and observational outcomes (e.g., counts correct on reading instruments). Substantive theory shows what interventions or manipulations to the measurement mechanism can be traded off against a change to the object measure to hold the observed outcome constant. A Rasch model integrated with a substantive theory dictates the form and substance of permissible interventions. Rasch analysis, absent construct theory and an associated specification equation, is a black box in which understanding may be more illusory than not. Finally, the quantitative hypothesis can be tested by comparing theory-based trade-off relations with observed trade-off relations. Only quantitative variables (as measured) support such trade-offs. Note that to test the quantitative hypothesis requires more than manipulation of the algebraic equivalencies in the Rasch model or descriptively fitting data to the model. A causal Rasch model involves experimental intervention/manipulation on either reader ability or text complexity or a conjoint intervention on both simultaneously to yield a successful prediction of the resultant observed outcome (count correct). We conjecture that when this type of manipulation is introduced for individual reader text encounters and model predictions are consistent with observations, the quantitative hypothesis is sustained.

  8. Causal Rasch models

    Science.gov (United States)

    Stenner, A. Jackson; Fisher, William P.; Stone, Mark H.; Burdick, Donald S.

    2013-01-01

    Rasch's unidimensional models for measurement show how to connect object measures (e.g., reader abilities), measurement mechanisms (e.g., machine-generated cloze reading items), and observational outcomes (e.g., counts correct on reading instruments). Substantive theory shows what interventions or manipulations to the measurement mechanism can be traded off against a change to the object measure to hold the observed outcome constant. A Rasch model integrated with a substantive theory dictates the form and substance of permissible interventions. Rasch analysis, absent construct theory and an associated specification equation, is a black box in which understanding may be more illusory than not. Finally, the quantitative hypothesis can be tested by comparing theory-based trade-off relations with observed trade-off relations. Only quantitative variables (as measured) support such trade-offs. Note that to test the quantitative hypothesis requires more than manipulation of the algebraic equivalencies in the Rasch model or descriptively fitting data to the model. A causal Rasch model involves experimental intervention/manipulation on either reader ability or text complexity or a conjoint intervention on both simultaneously to yield a successful prediction of the resultant observed outcome (count correct). We conjecture that when this type of manipulation is introduced for individual reader text encounters and model predictions are consistent with observations, the quantitative hypothesis is sustained. PMID:23986726

  9. 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.

  10. Causal Rasch models

    Directory of Open Access Journals (Sweden)

    A. Jackson Stenner

    2013-08-01

    Full Text Available Rasch’s unidimensional models for measurement show how to connect object measures (e.g., reader abilities, measurement mechanisms (e.g., machine-generated cloze reading items, and observational outcomes (e.g., counts correct on reading instruments. Substantive theory shows what interventions or manipulations to the measurement mechanism can be traded off against a change to the object measure to hold the observed outcome constant. A Rasch model integrated with a substantive theory dictates the form and substance of permissible interventions. Rasch analysis, absent construct theory and an associated specification equation, is a black box in which understanding may be more illusory than not. Finally, the quantitative hypothesis can be tested by comparing theory-based trade-off relations with observed trade-off relations. Only quantitative variables (as measured support such trade-offs. Note that to test the quantitative hypothesis requires more than manipulation of the algebraic equivalencies in the Rasch model or descriptively fitting data to the model. A causal Rasch model involves experimental intervention/manipulation on either reader ability or text complexity or a conjoint intervention on both simultaneously to yield a successful prediction of the resultant observed outcome (count correct. We conjecture that when this type of manipulation is introduced for individual reader text encounters and model predictions are consistent with observations, the quantitative hypothesis is sustained.

  11. Measuring Instrument Constructs of Return Factors for Green Office Building Investments Variables Using Rasch Measurement Model

    Directory of Open Access Journals (Sweden)

    Isa Mona

    2016-01-01

    Full Text Available This paper is a preliminary study on rationalising green office building investments in Malaysia. The aim of this paper is attempt to introduce the application of Rasch measurement model analysis to determine the validity and reliability of each construct in the questionnaire. In achieving this objective, a questionnaire survey was developed consists of 6 sections and a total of 106 responses were received from various investors who own and lease office buildings in Kuala Lumpur. The Rasch Measurement analysis is used to measure the quality control of item constructs in the instrument by measuring the specific objectivity within the same dimension, to reduce ambiguous measures, and a realistic estimation of precision and implicit quality. The Rasch analysis consists of the summary statistics, item unidimensionality and item measures. A result shows the items and respondent (person reliability is at 0.91 and 0.95 respectively.

  12. 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).

  13. 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

  14. 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.

  15. Using and Developing Measurement Instruments in Science Education: A Rasch Modeling Approach. Science & Engineering Education Sources

    Science.gov (United States)

    Liu, Xiufeng

    2010-01-01

    This book meets a demand in the science education community for a comprehensive and introductory measurement book in science education. It describes measurement instruments reported in refereed science education research journals, and introduces the Rasch modeling approach to developing measurement instruments in common science assessment domains,…

  16. 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…

  17. Using the Rasch Measurement Model in Psychometric Analysis of the Family Effectiveness Measure

    Science.gov (United States)

    McCreary, Linda L.; Conrad, Karen M.; Conrad, Kendon J.; Scott, Christy K; Funk, Rodney R.; Dennis, Michael L.

    2013-01-01

    Background Valid assessment of family functioning can play a vital role in optimizing client outcomes. Because family functioning is influenced by family structure, socioeconomic context, and culture, existing measures of family functioning--primarily developed with nuclear, middle class European American families--may not be valid assessments of families in diverse populations. The Family Effectiveness Measure was developed to address this limitation. Objectives To test the Family Effectiveness Measure with data from a primarily low-income African American convenience sample, using the Rasch measurement model. Method A sample of 607 adult women completed the measure. Rasch analysis was used to assess unidimensionality, response category functioning, item fit, person reliability, differential item functioning by race and parental status, and item hierarchy. Criterion-related validity was tested using correlations with five other variables related to family functioning. Results The Family Effectiveness Measure measures two separate constructs: The effective family functioning construct was a psychometrically sound measure of the target construct that was more efficient due to the deletion of 22 items. The ineffective family functioning construct consisted of 16 of those deleted items but was not as strong psychometrically. Items in both constructs evidenced no differential item functioning by race. Criterion-related validity was supported for both. Discussion In contrast to the prevailing conceptualization that family functioning is a single construct, assessed by positively and negatively worded items, use of the Rasch analysis suggested the existence of two constructs. While the effective family functioning is a strong and efficient measure of family functioning, the ineffective family functioning will require additional item development and psychometric testing. PMID:23636342

  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. Some Improved Diagnostics for Failure of The Rasch Model.

    Science.gov (United States)

    Molenaar, Ivo W.

    1983-01-01

    Goodness of fit tests for the Rasch model are typically large-sample, global measures. This paper offers suggestions for small-sample exploratory techniques for examining the fit of item data to the Rasch model. (Author/JKS)

  20. 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.

  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. Measurement of Online Student Engagement: Utilization of Continuous Online Student Behavior Indicators as Items in a Partial Credit Rasch Model

    Science.gov (United States)

    Anderson, Elizabeth

    2017-01-01

    Student engagement has been shown to be essential to the development of research-based best practices for K-12 education. It has been defined and measured in numerous ways. The purpose of this research study was to develop a measure of online student engagement for grades 3 through 8 using a partial credit Rasch model and validate the measure…

  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 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…

  4. 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

  5. Polytomous Rasch Models in Counseling Assessment

    Science.gov (United States)

    Willse, John T.

    2017-01-01

    This article provides a brief introduction to the Rasch model. Motivation for using Rasch analyses is provided. Important Rasch model concepts and key aspects of result interpretation are introduced, with major points reinforced using a simulation demonstration. Concrete guidelines are provided regarding sample size and the evaluation of items.

  6. Guessing and the Rasch Model

    Science.gov (United States)

    Holster, Trevor A.; Lake, J.

    2016-01-01

    Stewart questioned Beglar's use of Rasch analysis of the Vocabulary Size Test (VST) and advocated the use of 3-parameter logistic item response theory (3PLIRT) on the basis that it models a non-zero lower asymptote for items, often called a "guessing" parameter. In support of this theory, Stewart presented fit statistics derived from…

  7. 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

  8. Measuring Math Anxiety (in Spanish) with the Rasch Rating Scale Model.

    Science.gov (United States)

    Prieto, Gerardo; Delgado, Ana R

    2007-01-01

    Two successive studies probed the psychometric properties of a Math Anxiety questionnaire (in Spanish) by means of the Rasch Rating Scale Model. Participants were 411 and 216 Spanish adolescents. Convergent validity was examined by correlating the scale with both the Fennema and Sherman Attitude Scale and a math achievement test. The results show that the scores are psychometrically appropriate, and replicate those reported in meta-analyses: medium-sized negative correlations with achievement and with attitudes toward mathematics, as well as moderate sex-related differences (with girls presenting higher anxiety levels than boys).

  9. 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.

  10. 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.

  11. Examining Teacher Grades Using Rasch Measurement Theory

    Science.gov (United States)

    Randall, Jennifer; Engelhard, George, Jr.

    2009-01-01

    In this study, we present an approach to questionnaire design within educational research based on Guttman's mapping sentences and Many-Facet Rasch Measurement Theory. We designed a 54-item questionnaire using Guttman's mapping sentences to examine the grading practices of teachers. Each item in the questionnaire represented a unique student…

  12. 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...

  13. 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.

  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. 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…

  16. 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.

  17. Sample Size Determination for Rasch Model Tests

    Science.gov (United States)

    Draxler, Clemens

    2010-01-01

    This paper is concerned with supplementing statistical tests for the Rasch model so that additionally to the probability of the error of the first kind (Type I probability) the probability of the error of the second kind (Type II probability) can be controlled at a predetermined level by basing the test on the appropriate number of observations.…

  18. 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...

  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. 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…

  1. Rasch Measurement of Collaborative Problem Solving in an Online Environment.

    Science.gov (United States)

    Harding, Susan-Marie E; Griffin, Patrick E

    2016-01-01

    This paper describes an approach to the assessment of human to human collaborative problem solving using a set of online interactive tasks completed by student dyads. Within the dyad, roles were nominated as either A or B and students selected their own roles. The question as to whether role selection affected individual student performance measures is addressed. Process stream data was captured from 3402 students in six countries who explored the problem space by clicking, dragging the mouse, moving the cursor and collaborating with their partner through a chat box window. Process stream data were explored to identify behavioural indicators that represented elements of a conceptual framework. These indicative behaviours were coded into a series of dichotomous items. These items represented actions and chats performed by students. The frequency of occurrence was used as a proxy measure of item difficulty. Then given a measure of item difficulty, student ability could be estimated using the difficulty estimates of the range of items demonstrated by the student. The Rasch simple logistic model was used to review the indicators to identify those that were consistent with the assumptions of the model and were invariant across national samples, language, curriculum and age of the student. The data were analysed using a one and two dimension, one parameter model. Rasch separation reliability, fit to the model, distribution of students and items on the underpinning construct, estimates for each country and the effect of role differences are reported. This study provides evidence that collaborative problem solving can be assessed in an online environment involving human to human interaction using behavioural indicators shown to have a consistent relationship between the estimate of student ability, and the probability of demonstrating the behaviour.

  2. Rasch model based analysis of the Force Concept Inventory

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    Maja Planinic

    2010-03-01

    Full Text Available The Force Concept Inventory (FCI is an important diagnostic instrument which is widely used in the field of physics education research. It is therefore very important to evaluate and monitor its functioning using different tools for statistical analysis. One of such tools is the stochastic Rasch model, which enables construction of linear measures for persons and items from raw test scores and which can provide important insight in the structure and functioning of the test (how item difficulties are distributed within the test, how well the items fit the model, and how well the items work together to define the underlying construct. The data for the Rasch analysis come from the large-scale research conducted in 2006-07, which investigated Croatian high school students’ conceptual understanding of mechanics on a representative sample of 1676 students (age 17–18 years. The instrument used in research was the FCI. The average FCI score for the whole sample was found to be (27.7±0.4%, indicating that most of the students were still non-Newtonians at the end of high school, despite the fact that physics is a compulsory subject in Croatian schools. The large set of obtained data was analyzed with the Rasch measurement computer software WINSTEPS 3.66. Since the FCI is routinely used as pretest and post-test on two very different types of population (non-Newtonian and predominantly Newtonian, an additional predominantly Newtonian sample (N=141, average FCI score of 64.5% of first year students enrolled in introductory physics course at University of Zagreb was also analyzed. The Rasch model based analysis suggests that the FCI has succeeded in defining a sufficiently unidimensional construct for each population. The analysis of fit of data to the model found no grossly misfitting items which would degrade measurement. Some items with larger misfit and items with significantly different difficulties in the two samples of students do require further

  3. %lrasch_mml: A SAS Macro for Marginal Maximum Likelihood Estimation in Longitudinal Polytomous Rasch Models

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    Maja Olsbjerg

    2015-10-01

    Full Text Available Item response theory models are often applied when a number items are used to measure a unidimensional latent variable. Originally proposed and used within educational research, they are also used when focus is on physical functioning or psychological wellbeing. Modern applications often need more general models, typically models for multidimensional latent variables or longitudinal models for repeated measurements. This paper describes a SAS macro that fits two-dimensional polytomous Rasch models using a specification of the model that is sufficiently flexible to accommodate longitudinal Rasch models. The macro estimates item parameters using marginal maximum likelihood estimation. A graphical presentation of item characteristic curves is included.

  4. Enhancing measurement in science education research through Rasch analysis: Rationale and properties

    Directory of Open Access Journals (Sweden)

    Jørgen Sjaastad

    2014-10-01

    Full Text Available This article presents the basic rationale of Rasch theory and seven core properties of Rasch modeling; analyses of test targeting, person separation, person fit, item fit, differential item functioning, functioning of response categories and tests of unidimensionality. Illustrative examples are provided consecutively, drawing on Rasch analysis of data from a survey where students in the 9th grade responded to questions regarding their mathematics competence. The relationship between Rasch theory and classical test theory is commented on. Rasch theory provides science and mathematics education researchers with valuable tools to evaluate the psychometric quality of tests and questionnaires and support the development of these.

  5. Applying the Rasch Model to Measure Mobility of Women: A Comparative Analysis of Mobility of Informal Workers in Fisheries in Kerala, India.

    Science.gov (United States)

    Menon, Nikhila

    2016-01-01

    Mobility or freedom and ability to move is gendered in many cultural contexts. In this paper I analyse mobility associated with work from the capability approach perspective of Sen. This is an empirical paper which uses the Rasch Rating Scale Model (RSM) to construct the measure of mobility of women for the first time in the development studies discourse. I construct a measure of mobility (latent trait) of women workers engaged in two types of informal work, namely, peeling work and fish vending, in fisheries in the cultural context of India. The scale measure enables first, to test the unidimensionality of my construct of mobility of women and second, to analyse the domains of mobility of women workers. The comparative analysis of the scale of permissibility of mobility constructed using the RSM for the informal women workers shows that women face constraints on mobility in social and personal spaces in the socially advanced state of Kerala in India. Work mobility does not expand the real freedoms, hence work mobility can be termed as bounded capability which is a capability limited or bounded by either the social, cultural and gender norms or a combination of all of these. Therefore at the macro level, growth in informal employment in sectors like fisheries which improve mobility of women through work mobility does not necessarily expand the capability sets by contributing to greater freedoms and transformational mobility. This paper has a significant methodological contribution in that it uses an innovative method for the measurement of mobility of women in the development studies discipline.

  6. Measuring Mindfulness: A Rasch Analysis of the Freiburg Mindfulness Inventory

    Directory of Open Access Journals (Sweden)

    Siobhan Lynch

    2011-12-01

    Full Text Available The objective of the study was to assess the psychometric properties of the Freiburg Mindfulness Inventory (FMI-14 using a Rasch model approach in a cross-sectional design. The scale was administered to N = 130 British patients with different psychosomatic conditions. The scale failed to show clear one-factoriality and item 13 did not fit the Rasch model. A two-factorial solution without item 13, however, appeared to fit well. The scale seemed to work equally well in different subgroups such as patients with or without mindfulness practice. However, some limitations of the validity of both the one-factorial and the two-factorial version of the scale were observed. Sizeable floor and ceiling effects limit the diagnostical use of the instrument. In summary, the study demonstrates that the two-factorial version of the FMI-13 shows acceptable approximation to Rasch requirements, but is in need of further improvement. The one-factorial solution did not fit well, and cannot be recommended for further use.

  7. A psychometric revision of the Asian values scale using the Rasch model

    OpenAIRE

    Kim, Bryan S. K.; Hong, Sehee

    2004-01-01

    The 36-item Asian Values Scale (B. S. K. Kim, D. R. Atkinson, & P H. Yang, 1999) was revised on the basis of G. Rasch (1960) model and data from 618 Asian Americans. The results led to the establishment of a 25-item measure named the Asian Values Scale-Revised.

  8. The Development of a Secondary-Level Solo Wind Instrument Performance Rubric Using the Multifaceted Rasch Partial Credit Measurement Model

    Science.gov (United States)

    Wesolowski, Brian C.; Amend, Ross M.; Barnstead, Thomas S.; Edwards, Andrew S.; Everhart, Matthew; Goins, Quentin R.; Grogan, Robert J., III; Herceg, Amanda M.; Jenkins, S. Ira; Johns, Paul M.; McCarver, Christopher J.; Schaps, Robin E.; Sorrell, Gary W.; Williams, Jonathan D.

    2017-01-01

    The purpose of this study was to describe the development of a valid and reliable rubric to assess secondary-level solo instrumental music performance based on principles of invariant measurement. The research questions that guided this study included (1) What is the psychometric quality (i.e., validity, reliability, and precision) of a scale…

  9. 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.

  10. Rasch model analysis of the Depression, Anxiety and Stress Scales (DASS).

    Science.gov (United States)

    Shea, Tracey L; Tennant, Alan; Pallant, Julie F

    2009-05-09

    There is a growing awareness of the need for easily administered, psychometrically sound screening tools to identify individuals with elevated levels of psychological distress. Although support has been found for the psychometric properties of the Depression, Anxiety and Stress Scales (DASS) using classical test theory approaches it has not been subjected to Rasch analysis. The aim of this study was to use Rasch analysis to assess the psychometric properties of the DASS-21 scales, using two different administration modes. The DASS-21 was administered to 420 participants with half the sample responding to a web-based version and the other half completing a traditional pencil-and-paper version. Conformity of DASS-21 scales to a Rasch partial credit model was assessed using the RUMM2020 software. To achieve adequate model fit it was necessary to remove one item from each of the DASS-21 subscales. The reduced scales showed adequate internal consistency reliability, unidimensionality and freedom from differential item functioning for sex, age and mode of administration. Analysis of all DASS-21 items combined did not support its use as a measure of general psychological distress. A scale combining the anxiety and stress items showed satisfactory fit to the Rasch model after removal of three items. The results provide support for the measurement properties, internal consistency reliability, and unidimensionality of three slightly modified DASS-21 scales, across two different administration methods. The further use of Rasch analysis on the DASS-21 in larger and broader samples is recommended to confirm the findings of the current study.

  11. Rasch model analysis of the Depression, Anxiety and Stress Scales (DASS)

    Science.gov (United States)

    Shea, Tracey L; Tennant, Alan; Pallant, Julie F

    2009-01-01

    Background There is a growing awareness of the need for easily administered, psychometrically sound screening tools to identify individuals with elevated levels of psychological distress. Although support has been found for the psychometric properties of the Depression, Anxiety and Stress Scales (DASS) using classical test theory approaches it has not been subjected to Rasch analysis. The aim of this study was to use Rasch analysis to assess the psychometric properties of the DASS-21 scales, using two different administration modes. Methods The DASS-21 was administered to 420 participants with half the sample responding to a web-based version and the other half completing a traditional pencil-and-paper version. Conformity of DASS-21 scales to a Rasch partial credit model was assessed using the RUMM2020 software. Results To achieve adequate model fit it was necessary to remove one item from each of the DASS-21 subscales. The reduced scales showed adequate internal consistency reliability, unidimensionality and freedom from differential item functioning for sex, age and mode of administration. Analysis of all DASS-21 items combined did not support its use as a measure of general psychological distress. A scale combining the anxiety and stress items showed satisfactory fit to the Rasch model after removal of three items. Conclusion The results provide support for the measurement properties, internal consistency reliability, and unidimensionality of three slightly modified DASS-21 scales, across two different administration methods. The further use of Rasch analysis on the DASS-21 in larger and broader samples is recommended to confirm the findings of the current study. PMID:19426512

  12. Rasch model analysis of the Depression, Anxiety and Stress Scales (DASS

    Directory of Open Access Journals (Sweden)

    Tennant Alan

    2009-05-01

    Full Text Available Abstract Background There is a growing awareness of the need for easily administered, psychometrically sound screening tools to identify individuals with elevated levels of psychological distress. Although support has been found for the psychometric properties of the Depression, Anxiety and Stress Scales (DASS using classical test theory approaches it has not been subjected to Rasch analysis. The aim of this study was to use Rasch analysis to assess the psychometric properties of the DASS-21 scales, using two different administration modes. Methods The DASS-21 was administered to 420 participants with half the sample responding to a web-based version and the other half completing a traditional pencil-and-paper version. Conformity of DASS-21 scales to a Rasch partial credit model was assessed using the RUMM2020 software. Results To achieve adequate model fit it was necessary to remove one item from each of the DASS-21 subscales. The reduced scales showed adequate internal consistency reliability, unidimensionality and freedom from differential item functioning for sex, age and mode of administration. Analysis of all DASS-21 items combined did not support its use as a measure of general psychological distress. A scale combining the anxiety and stress items showed satisfactory fit to the Rasch model after removal of three items. Conclusion The results provide support for the measurement properties, internal consistency reliability, and unidimensionality of three slightly modified DASS-21 scales, across two different administration methods. The further use of Rasch analysis on the DASS-21 in larger and broader samples is recommended to confirm the findings of the current study.

  13. Measuring situational avoidance in older drivers: An application of Rasch analysis.

    Science.gov (United States)

    Davis, Jessica; Conlon, Elizabeth; Ownsworth, Tamara; Morrissey, Shirley

    2016-02-01

    Situational avoidance is a form of driving self-regulation at the strategic level of driving behaviour. It has typically been defined as the purposeful avoidance of driving situations perceived as challenging or potentially hazardous. To date, assessment of the psychometric properties of existing scales that measure situational avoidance has been sparse. This study examined the contribution of Rasch analysis to the situational avoidance construct. Three hundred and ninety-nine Australian drivers (M=66.75, SD=10.14, range: 48-91 years) completed the Situational Avoidance Questionnaire (SAQ). Following removal of the item Parallel Parking, the scale conformed to a Rasch model, showing good person separation, sufficient reliability, little disordering of thresholds, and no evidence of differential item functioning by age or gender. The residuals were independent supporting the assumption of unidimensionality and in conforming to a Rasch model, SAQ items were found to be hierarchical or cumulative. Increased avoidance was associated with factors known to be related to driving self-regulation more broadly, including older age, female gender, reduced driving space and frequency, reporting a change in driving in the past five years and poorer indices of health (i.e., self-rated mood, vision and cognitive function). Overall, these results support the use of the SAQ as a psychometrically sound measure of situational avoidance. Application of Rasch analysis to this area of research advances understanding of the driving self-regulation construct and its practice by drivers in baby boomer and older adult generations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Rasch-modeling the Portuguese SOCRATES in a clinical sample.

    Science.gov (United States)

    Lopes, Paulo; Prieto, Gerardo; Delgado, Ana R; Gamito, Pedro; Trigo, Hélder

    2010-06-01

    The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES) assesses motivation for treatment in the drug-dependent population. The development of adequate measures of motivation is needed in order to properly understand the role of this construct in rehabilitation. This study probed the psychometric properties of the SOCRATES in the Portuguese population by means of the Rasch Rating Scale Model, which allows the conjoint measurement of items and persons. The participants were 166 substance abusers under treatment for their addiction. Results show that the functioning of the five response categories is not optimal; our re-analysis indicates that a three-category system is the most appropriate one. By using this response category system, both model fit and estimation accuracy are improved. The discussion takes into account other factors such as item format and content in order to make suggestions for the development of better motivation-for-treatment scales. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  15. 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.

  16. Power analysis on the time effect for the longitudinal Rasch model.

    Science.gov (United States)

    Feddag, M L; Blanchin, M; Hardouin, J B; Sebille, V

    2014-01-01

    Statistics literature in the social, behavioral, and biomedical sciences typically stress the importance of power analysis. Patient Reported Outcomes (PRO) such as quality of life and other perceived health measures (pain, fatigue, stress,...) are increasingly used as important health outcomes in clinical trials or in epidemiological studies. They cannot be directly observed nor measured as other clinical or biological data and they are often collected through questionnaires with binary or polytomous items. The Rasch model is the well known model in the item response theory (IRT) for binary data. The article proposes an approach to evaluate the statistical power of the time effect for the longitudinal Rasch model with two time points. The performance of this method is compared to the one obtained by simulation study. Finally, the proposed approach is illustrated on one subscale of the SF-36 questionnaire.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Rasch family models in e-learning: analyzing architectural sketching with a digital pen.

    Science.gov (United States)

    Scalise, Kathleen; Cheng, Nancy Yen-Wen; Oskui, Nargas

    2009-01-01

    Since architecture students studying design drawing are usually assessed qualitatively on the basis of their final products, the challenges and stages of their learning have remained masked. To clarify the challenges in design drawing, we have been using the BEAR Assessment System and Rasch family models to measure levels of understanding for individuals and groups, in order to correct pedagogical assumptions and tune teaching materials. This chapter discusses the analysis of 81 drawings created by architectural students to solve a space layout problem, collected and analyzed with digital pen-and-paper technology. The approach allows us to map developmental performance criteria and perceive achievement overlaps in learning domains assumed separate, and then re-conceptualize a three-part framework to represent learning in architectural drawing. Results and measurement evidence from the assessment and Rasch modeling are discussed.

  19. 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…

  20. Revalidating the Arabic Scale for Teachers' Ratings of Basic Education Gifted Students' Characteristics Using Rasch Modeling

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    Salah Eldin Farah Atallah Bakheit

    2013-12-01

    Full Text Available The Arabic scale for teachers' ratings of basic education gifted students' characteristics is one of the most common Arabic measures used for initial identification of gifted students in some Arabic countries. One of the shortcomings of this scale is that it is based on the classical the-ory of measurement. This study sought to reval-idate the scale in the light of Rasch modeling which rests upon the modern theory of meas-urement and to develop different criteria for in-terpreting the levels of individuals' traits. The scale was administered to 830 of Basic Educa-tion students in Khartoum (ages ranged from 7 to 12 years. Two groups of students partici-pated in the study: a calibration sample (N = 250 and a standardization sample (N = 580. The statistical treatments were performed using the PSAW 18 and RUMM 2020 programs ac-cording to Rasch's unidimentional model. Six of the scale's items were deleted for not conform-ing to Rasch Modeling. This left the scale with 31 items. Besides, new criteria for the scale were developed by obtaining the t-scores and special education scores that match the various ratings of the individuals' ability.

  1. 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

  2. Detecting Aberrant Response Patterns in the Rasch Model. Rapport 87-3.

    Science.gov (United States)

    Kogut, Jan

    In this paper, the detection of response patterns aberrant from the Rasch model is considered. For this purpose, a new person fit index, recently developed by I. W. Molenaar (1987) and an iterative estimation procedure are used in a simulation study of Rasch model data mixed with aberrant data. Three kinds of aberrant response behavior are…

  3. A psychometric revision of the European American Values Scale for Asian Americans using the Rasch model

    OpenAIRE

    Hong, S; Kim, Bryan S.K.; Wolfe, M M

    2005-01-01

    The 18-item European American Values Scale for Asian Americans (M. M. Wolfe, P H. Yang, E C. Wong, & D. R. Atkinson, 2001) was revised on the basis of results from a psychometric analysis using the Rasch Model (G. Rasch,1960). The results led to the establishment of the 25-item European AmericanValues Scale for Asian Americans-Revised.

  4. 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.

  5. 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...

  6. Emotional vitality in caregivers: application of Rasch Measurement Theory with secondary data to development and test a new measure.

    Science.gov (United States)

    Barbic, Skye P; Bartlett, Susan J; Mayo, Nancy E

    2015-07-01

    To describe the practical steps in identifying items and evaluating scoring strategies for a new measure of emotional vitality in informal caregivers of individuals who have experienced a significant health event. The psychometric properties of responses to selected items from validated health-related quality of life and other psychosocial questionnaires administered four times over a one-year period were evaluated using Rasch Measurement Theory. Community. A total of 409 individuals providing informal care at home to older adults who had experienced a recent stroke. Rasch Measurement Theory was used to test the ordering of response option thresholds, fit, spread of the item locations, residual correlations, person separation index, and stability across time. Based on a theoretical framework developed in earlier work, we identified 22 candidate items from a pool of relevant psychosocial measures available. Of these, additional evaluation resulted in 19 items that could be used to assess the five core domains. The overall model fit was reasonable (χ(2) = 202.26, DF = 117, p = 0.06), stable across time, with borderline evidence of multidimensionality (10%). Items and people covered a continuum ranging from -3.7 to +2.7 logits, reflecting coverage of the measurement continuum, with a person separation index of 0.85. Mean fit of caregivers was lower than expected (-1.31 ±1.10 logits). Established methods from the Rasch Measurement Theory were applied to develop a prototype measure of emotional vitality that is acceptable, reliable, and can be used to obtain an interval level score for use in future research and clinical settings. © The Author(s) 2014.

  7. Using the Rasch model as an objective and probabilistic technique to integrate different soil properties

    Science.gov (United States)

    Rebollo, Francisco J.; Jesús Moral García, Francisco

    2016-04-01

    Soil apparent electrical conductivity (ECa) is one of the simplest, least expensive soil measurements that integrates many soil properties affecting crop productivity, including, for instance, soil texture, water content, and cation exchange capacity. The ECa measurements obtained with a 3100 Veris sensor, operating in both shallow (0-30 cm), ECs, and deep (0-90 cm), ECd, mode, can be used as an additional and essential information to be included in a probabilistic model, the Rasch model, with the aim of quantifying the overall soil fertililty potential in an agricultural field. This quantification should integrate the main soil physical and chemical properties, with different units. In this work, the formulation of the Rasch model integrates 11 soil properties (clay, silt and sand content, organic matter -OM-, pH, total nitrogen -TN-, available phosphorus -AP- and potassium -AK-, cation exchange capacity -CEC-, ECd, and ECs) measured at 70 locations in a field. The main outputs of the model include a ranking of all soil samples according to their relative fertility potential and the unexpected behaviours of some soil samples and properties. In the case study, the considered soil variables fit the model reasonably, having an important influence on soil fertility, except pH, probably due to its homogeneity in the field. Moreover, ECd, ECs are the most influential properties on soil fertility and, on the other hand, AP and AK the less influential properties. The use of the Rasch model to estimate soil fertility potential (always in a relative way, taking into account the characteristics of the studied soil) constitutes a new application of great practical importance, enabling to rationally determine locations in a field where high soil fertility potential exists and establishing those soil samples or properties which have any anomaly; this information can be necessary to conduct site-specific treatments, leading to a more cost-effective and sustainable field

  8. Historical Views of Invariance: Evidence from the Measurement Theories of Thorndike, Thurstone, and Rasch.

    Science.gov (United States)

    Engelhard, George, Jr.

    1992-01-01

    A historical perspective is provided of the concept of invariance in measurement theory, describing sample-invariant item calibration and item-invariant measurement of individuals. Invariance as a key measurement concept is illustrated through the measurement theories of E. L. Thorndike, L. L. Thurstone, and G. Rasch. (SLD)

  9. Validation of the brief version of the Recovery Self-Assessment (RSA-B) using Rasch measurement theory.

    Science.gov (United States)

    Barbic, Skye P; Kidd, Sean A; Davidson, Larry; McKenzie, Kwame; O'Connell, Maria J

    2015-12-01

    In psychiatry, the recovery paradigm is increasingly identified as the overarching framework for service provision. Currently, the Recovery Self-Assessment (RSA), a 36-item rating scale, is commonly used to assess the uptake of a recovery orientation in clinical services. However, the consumer version of the RSA has been found challenging to complete because of length and the reading level required. In response to this feedback, a brief 12-item version of the RSA was developed (RSA-B). This article describes the development of the modified instrument and the application of traditional psychometric analysis and Rasch Measurement Theory to test the psychometrics properties of the RSA-B. Data from a multisite study of adults with serious mental illnesses (n = 1256) who were followed by assertive community treatment teams were examined for reliability, clinical meaning, targeting, response categories, model fit, reliability, dependency, and raw interval-level measurement. Analyses were performed using the Rasch Unidimensional Measurement Model (RUMM 2030). Adequate fit to the Rasch model was observed (χ2 = 112.46, df = 90, p = .06) and internal consistency was good (r = .86). However, Rasch analysis revealed limitations of the 12-item version, with items covering only 39% of the targeted theoretical continuum, 2 misfitting items, and strong evidence for the 5 option response categories not working as intended. This study revealed areas for improvement in the shortened version of the 12-item RSA-B. A revisit of the conceptual model and original 36-item rating scale is encouraged to select items that will help practitioners and researchers measure the full range of recovery orientation. (c) 2015 APA, all rights reserved).

  10. 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.

  11. 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.

  12. Thorndike, Thurstone and Rasch: A Comparison of Their Approaches to Item-Invariant Measurement.

    Science.gov (United States)

    Englehard, George, Jr.

    The methods used by E. L. Thorndike, L. L. Thurstone, and G. Rasch to address issues related to item-invariant measurement and the scoring of individual performance are compared. The analyses highlight the close connection among the three methods, and suggest that progress in measurement theory reflects the movement from essentially ad hoc methods…

  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. 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.

  15. Exploring the measurement properties of the osteopathy clinical teaching questionnaire using Rasch analysis.

    Science.gov (United States)

    Vaughan, Brett

    2018-01-01

    Clinical teaching evaluations are common in health profession education programs to ensure students are receiving a quality clinical education experience. Questionnaires students use to evaluate their clinical teachers have been developed in professions such as medicine and nursing. The development of a questionnaire that is specifically for the osteopathy on-campus, student-led clinic environment is warranted. Previous work developed the 30-item Osteopathy Clinical Teaching Questionnaire. The current study utilised Rasch analysis to investigate the construct validity of the Osteopathy Clinical Teaching Questionnaire and provide evidence for the validity argument through fit to the Rasch model. Senior osteopathy students at four institutions in Australia, New Zealand and the United Kingdom rated their clinical teachers using the Osteopathy Clinical Teaching Questionnaire. Three hundred and ninety-nine valid responses were received and the data were evaluated for fit to the Rasch model. Reliability estimations (Cronbach's alpha and McDonald's omega) were also evaluated for the final model. The initial analysis demonstrated the data did not fit the Rasch model. Accordingly, modifications to the questionnaire were made including removing items, removing person responses, and rescoring one item. The final model contained 12 items and fit to the Rasch model was adequate. Support for unidimensionality was demonstrated through both the Principal Components Analysis/t-test, and the Cronbach's alpha and McDonald's omega reliability estimates. Analysis of the questionnaire using McDonald's omega hierarchical supported a general factor (quality of clinical teaching in osteopathy). The evidence for unidimensionality and the presence of a general factor support the calculation of a total score for the questionnaire as a sufficient statistic. Further work is now required to investigate the reliability of the 12-item Osteopathy Clinical Teaching Questionnaire to provide evidence

  16. 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

  17. 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…

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

    Science.gov (United States)

    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.…

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

    Science.gov (United States)

    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…

  20. Validity study of the Beck Anxiety Inventory (Portuguese version by the Rasch Rating Scale model

    Directory of Open Access Journals (Sweden)

    Sónia Quintão

    2013-01-01

    Full Text Available Our objective was to conduct a validation study of the Portuguese version of the Beck Anxiety Inventory (BAI by means of the Rasch Rating Scale Model, and then compare it with the most used scales of anxiety in Portugal. The sample consisted of 1,160 adults (427 men and 733 women, aged 18-82 years old (M=33.39; SD=11.85. Instruments were Beck Anxiety Inventory, State-Trait Anxiety Inventory and Zung Self-Rating Anxiety Scale. It was found that Beck Anxiety Inventory's system of four categories, the data-model fit, and people reliability were adequate. The measure can be considered as unidimensional. Gender and age-related differences were not a threat to the validity. BAI correlated significantly with other anxiety measures. In conclusion, BAI shows good psychometric quality.

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

    DEFF Research Database (Denmark)

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

    of the Danish language version of the PSS in a community sample of 1110 mothers of children aged 0 to 12 months employing the Rasch family of IRT models, and emphasizing the issues of unidimensionality and equal item functioning (no DIF) relative to the age and educational levels of the mothers. No adequate fit......) 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...... of the mothers. The parental satisfaction subscale fit a model adjusted only for local response dependence. The findings are in line with the original interpretation of the PSS. We recommend that the scoring of the PSS is changed to reflect the two subscales and the dichotomization of response categories...

  2. Item and response-category functioning of the Persian version of the KIDSCREEN-27: Rasch partial credit model

    Directory of Open Access Journals (Sweden)

    Jafari Peyman

    2012-10-01

    Full Text Available Abstract Background The purpose of the study was to determine whether the Persian version of the KIDSCREEN-27 has the optimal number of response category to measure health-related quality of life (HRQoL in children and adolescents. Moreover, we aimed to determine if all the items contributed adequately to their own domain. Findings The Persian version of the KIDSCREEN-27 was completed by 1083 school children and 1070 of their parents. The Rasch partial credit model (PCM was used to investigate item statistics and ordering of response categories. The PCM showed that no item was misfitting. The PCM also revealed that, successive response categories for all items were located in the expected order except for category 1 in self- and proxy-reports. Conclusions Although Rasch analysis confirms that all the items belong to their own underlying construct, response categories should be reorganized and evaluated in further studies, especially in children with chronic conditions.

  3. Protocol: validation of the INCODE barometer to measure the innovation compe-tence through the Rasch Measurement Theory

    Directory of Open Access Journals (Sweden)

    Lidia Sanchez

    2017-06-01

    Full Text Available This communication presents a protocol in order to show the different phases that must be followed in order to validate the INCODE barometer, which is used to measure the innovation competence, with Rasch Measurement Theory. Five phases are stated: dimensionality analysis, individual reliability and validity analysis of ítems and persons, global reliability and validity analysis, and cathegory analysis.

  4. Quantifying Local, Response Dependence between Two Polytomous Items Using the Rasch Model

    Science.gov (United States)

    Andrich, David; Humphry, Stephen M.; Marais, Ida

    2012-01-01

    Models of modern test theory imply statistical independence among responses, generally referred to as "local independence." 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 as a process in the dichotomous Rasch model,…

  5. 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...

  6. 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.

  7. 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

  8. Using the Mixture Rasch Model to Explore Knowledge Resources Students Invoke in Mathematic and Science Assessments

    Science.gov (United States)

    Zhang, Danhui; Orrill, Chandra; Campbell, Todd

    2015-01-01

    The purpose of this study was to investigate whether mixture Rasch models followed by qualitative item-by-item analysis of selected Programme for International Student Assessment (PISA) mathematics and science items offered insight into knowledge students invoke in mathematics and science separately and combined. The researchers administered an…

  9. 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.

  10. 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....

  11. 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.

  12. 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.

  13. Measuring health-related problem solving among African Americans with multiple chronic conditions: application of Rasch analysis.

    Science.gov (United States)

    Fitzpatrick, Stephanie L; Hill-Briggs, Felicia

    2015-10-01

    Identification of patients with poor chronic disease self-management skills can facilitate treatment planning, determine effectiveness of interventions, and reduce disease complications. This paper describes the use of a Rasch model, the Rating Scale Model, to examine psychometric properties of the 50-item Health Problem-Solving Scale (HPSS) among 320 African American patients with high risk for cardiovascular disease. Items on the positive/effective HPSS subscales targeted patients at low, moderate, and high levels of positive/effective problem solving, whereas items on the negative/ineffective problem solving subscales mostly targeted those at moderate or high levels of ineffective problem solving. Validity was examined by correlating factor scores on the measure with clinical and behavioral measures. Items on the HPSS show promise in the ability to assess health-related problem solving among high risk patients. However, further revisions of the scale are needed to increase its usability and validity with large, diverse patient populations in the future.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Multi-faceted Rasch measurement and bias patterns in EFL writing performance assessment.

    Science.gov (United States)

    He, Tung-Hsien; Gou, Wen Johnny; Chien, Ya-Chen; Chen, I-Shan Jenny; Chang, Shan-Mao

    2013-04-01

    This study applied multi-faceted Rasch measurement to examine rater bias in the assessment of essays written by college students learning English as a foreign language. Four raters who had received different academic training from four distinctive disciplines applied a six-category rating scale to analytically rate essays on an argumentative topic and on a descriptive topic. FACETS, a Rasch computer program, was utilized to pinpoint bias patterns by analyzing the rater-topic, rater-category, and topic-category interactions. Results showed: argumentative essays were rated more severely than were descriptive essays; the linguistics-major rater was the most lenient rater, while the literature-major rater was the severest one; and the category of language use received the severest ratings, whereas content was given the most lenient ratings. The severity hierarchies for raters, essay topics, and rating categories suggested that raters' academic training and their perceptions of the importance of categories were associated with their bias patterns. Implications for rater training are discussed.

  20. 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.

  1. 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…

  2. 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.

  3. 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.

  4. 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…

  5. 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.

  6. Comparison of formula and number-right scoring in undergraduate medical training: a Rasch model analysis.

    Science.gov (United States)

    Cecilio-Fernandes, Dario; Medema, Harro; Collares, Carlos Fernando; Schuwirth, Lambert; Cohen-Schotanus, Janke; Tio, René A

    2017-11-09

    Progress testing is an assessment tool used to periodically assess all students at the end-of-curriculum level. Because students cannot know everything, it is important that they recognize their lack of knowledge. For that reason, the formula-scoring method has usually been used. However, where partial knowledge needs to be taken into account, the number-right scoring method is used. Research comparing both methods has yielded conflicting results. As far as we know, in all these studies, Classical Test Theory or Generalizability Theory was used to analyze the data. In contrast to these studies, we will explore the use of the Rasch model to compare both methods. A 2 × 2 crossover design was used in a study where 298 students from four medical schools participated. A sample of 200 previously used questions from the progress tests was selected. The data were analyzed using the Rasch model, which provides fit parameters, reliability coefficients, and response option analysis. The fit parameters were in the optimal interval ranging from 0.50 to 1.50, and the means were around 1.00. The person and item reliability coefficients were higher in the number-right condition than in the formula-scoring condition. The response option analysis showed that the majority of dysfunctional items emerged in the formula-scoring condition. The findings of this study support the use of number-right scoring over formula scoring. Rasch model analyses showed that tests with number-right scoring have better psychometric properties than formula scoring. However, choosing the appropriate scoring method should depend not only on psychometric properties but also on self-directed test-taking strategies and metacognitive skills.

  7. 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

  8. Rasch measurement of self-regulated learning in an information and communication technology (ICT)-rich environment.

    Science.gov (United States)

    Njiru, Joseph N; Waugh, Russell F

    2007-01-01

    This report describes how a linear scale of self-regulated learning in an ICT-rich environment was created by analysing student data using the Rasch measurement model. A person convenience sample of (N = 409) university students in Western Australia was used. The stem-item sample was initially 41, answered in two perspectives ("I aim for this" and "I actually do this"), and reduced to 16 that fitted the measurement model to form a unidimensional scale. Items for motivation (extrinsic rewards, intrinsic rewards, and social rewards), academic goals (fear of performing poorly) (but not standards), self-learning beliefs (ability and interest), task management (strategies and time management) (but not cooperative learning), Volition (action control (but not environmental control), and self-evaluation (cognitive self-evaluation and metacognition) fitted the measurement model. The proportion of observed variance considered true was 0.90. A new instrument is proposed to handle the conceptually valid but non-fitting items. Characteristics of high self-regulated learners are measured.

  9. 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...... with Chronbach's alpha of 0.77-0.95 was evident. External construct validity was supported by expected high correlations with most of the constructs related to ingestive skills (r(s)¿=¿0.53 to r(s)¿=¿0.66). The MISA-DK discriminated significantly between known-groups. Fit to the Rasch model (x(2) (df)¿=¿12 (12...

  10. A constrained rasch model of trace redintegration in serial recall.

    Science.gov (United States)

    Roodenrys, Steven; Miller, Leonie M

    2008-04-01

    The notion that verbal short-term memory tasks, such as serial recall, make use of information in long-term as well as in short-term memory is instantiated in many models of these tasks. Such models incorporate a process in which degraded traces retrieved from a short-term store are reconstructed, or redintegrated (Schweickert, 1993), through the use of information in long-term memory. This article presents a conceptual and mathematical model of this process based on a class of item-response theory models. It is demonstrated that this model provides a better fit to three sets of data than does the multinomial processing tree model of redintegration (Schweickert, 1993) and that a number of conceptual accounts of serial recall can be related to the parameters of the model.

  11. A Multi-Marker Genetic Association Test Based on the Rasch Model Applied to Alzheimer's Disease.

    Directory of Open Access Journals (Sweden)

    Wenjia Wang

    Full Text Available Results from Genome-Wide Association Studies (GWAS have shown that the genetic basis of complex traits often include many genetic variants with small to moderate effects whose identification remains a challenging problem. In this context multi-marker analysis at the gene and pathway level can complement traditional point-wise approaches that treat the genetic markers individually. In this paper we propose a novel statistical approach for multi-marker analysis based on the Rasch model. The method summarizes the categorical genotypes of SNPs by a generalized logistic function into a genetic score that can be used for association analysis. Through different sets of simulations, the false-positive rate and power of the proposed approach are compared to a set of existing methods, and shows good performances. The application of the Rasch model on Alzheimer's Disease (AD ADNI GWAS dataset also allows a coherent interpretation of the results. Our analysis supports the idea that APOE is a major susceptibility gene for AD. In the top genes selected by proposed method, several could be functionally linked to AD. In particular, a pathway analysis of these genes also highlights the metabolism of cholesterol, that is known to play a key role in AD pathogenesis. Interestingly, many of these top genes can be integrated in a hypothetic signalling network.

  12. Analysis of the Professional Choice Self-Efficacy Scale Using the Rasch-Andrich Rating Scale Model

    Science.gov (United States)

    Ambiel, Rodolfo A. M.; Noronha, Ana Paula Porto; de Francisco Carvalho, Lucas

    2015-01-01

    The aim of this research was to analyze the psychometrics properties of the professional choice self-efficacy scale (PCSES), using the Rasch-Andrich rating scale model. The PCSES assesses four factors: self-appraisal, gathering occupational information, practical professional information search and future planning. Participants were 883 Brazilian…

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. An application of dichotomous and polytomous Rasch models for scoring energy insecurity

    International Nuclear Information System (INIS)

    Murray, Anthony G.; Mills, Bradford F.

    2012-01-01

    Household food security in the United States has been extensively researched and a number of indexes have been generated. However, household energy security has been largely ignored even though low-income households spend almost equal income shares on food and energy. This paper uses Rasch models and household responses to energy security questions in the 2005 Residential Energy Consumption Survey to generate an energy insecurity index that is consistent with those found in the food insecurity literature. The analysis yields several important findings for the generation of policy relevant household energy insecurity indexes. Questions that indicate reduction of basic expenditures, such as food, clothing, and shelter, are easiest for households to affirm implying low exposure to energy insecurity. Conversely, questions that concern households leaving the residence due to extreme temperatures consistently imply high exposure to energy insecurity. Households that score in the top decile of the energy insecurity index are more likely to be headed by single-females, be younger, and have a Black household head. Rasch models also identify flaws within survey. Particularly, the scope of the questions is quite broad and a refinement of the survey questions to focus on specific attributes of energy insecurity would likely improve future energy security indexes. - Highlights: ► A novel household energy insecurity index is generated for low-income U.S. families. ► Severely energy insecure households have unique characteristics. ► Energy insecure households are more likely to participate in LIHEAP. ► RECS survey questions should be modified for an improved energy insecurity index.

  18. 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.

  19. Validation of the malaysian versions of parents and children health survey for asthma by using rasch-model.

    Science.gov (United States)

    Hussein, Maryam Se; Akram, Waqas; Mamat, Mohd Nor; Majeed, Abu Bakar Abdul; Ismail, Nahlah Elkudssiah Binti

    2015-04-01

    In recent years, health-related quality of life (HRQOL) has become an important outcome measure in epidemiologic studies and clinical trials. For patients with asthma there are many instruments but most of them have been developed in English. With the increase in research project, researchers working in other languages have two options; either to develop a new measure or to translate an already developed measure. Children Health Survey for Asthma is developed by American Academy of Paediatrics which has two versions one for the parents (CHSA) and the other for the child (CHSA-C). However, there is no Malay version of the CHSA or the CHSA-C. The aim of this study was to translate and determine the validity and reliability of the Malaysian versions of Parent and Children Health Survey for Asthma. Questionnaires were translated to Bahasa Malayu using previously established guidelines, data from 180 respondents (asthmatic children and their parent) were analysed using Rasch-Model; as, it is an approach that has been increasingly used in health field and also it explores the performance of each item rather than total set score. The internal consistency was high for the parent questionnaire (CHSA) (reliability score for persons = 0.88 and for items was 0.97), and good for child questionnaire (CHSA-C) (reliability score for persons = 0.83 and for items was 0.94). Also, this study shows that all items measure for both questionnaires (CHSA and CHSA-C) are fitted to Rasch-Model. This study produced questionnaires that are conceptually equivalent to the original, easy to understand for the children and their parents, and good in terms of internal consistency. Because of the questionnaire has two versions one for the child and the other for the parents, they could be used in clinical practice to measure the effect of asthma on the child and their families. This current research had translated two instruments to other language (BahasaMalayu) and evaluated their reliability and

  20. Rasch-family models are more valuable than score-based approaches for analysing longitudinal patient-reported outcomes with missing data.

    Science.gov (United States)

    de Bock, Élodie; Hardouin, Jean-Benoit; Blanchin, Myriam; Le Neel, Tanguy; Kubis, Gildas; Bonnaud-Antignac, Angélique; Dantan, Étienne; Sébille, Véronique

    2016-10-01

    The objective was to compare classical test theory and Rasch-family models derived from item response theory for the analysis of longitudinal patient-reported outcomes data with possibly informative intermittent missing items. A simulation study was performed in order to assess and compare the performance of classical test theory and Rasch model in terms of bias, control of the type I error and power of the test of time effect. The type I error was controlled for classical test theory and Rasch model whether data were complete or some items were missing. Both methods were unbiased and displayed similar power with complete data. When items were missing, Rasch model remained unbiased and displayed higher power than classical test theory. Rasch model performed better than the classical test theory approach regarding the analysis of longitudinal patient-reported outcomes with possibly informative intermittent missing items mainly for power. This study highlights the interest of Rasch-based models in clinical research and epidemiology for the analysis of incomplete patient-reported outcomes data. © The Author(s) 2013.

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

    Science.gov (United States)

    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.

  2. 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.

  3. 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

    item dependency was observed between ICF categories of the same chapters. Group effects for age and sex were observed only to a small extent. CONCLUSIONS: The validity of ICF categories to develop measures of functioning in SCI for clinical practice and research is to some extent supported. Model......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...... 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...

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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

  7. 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).

  8. Using Rasch Measurement To Investigate the Cross-form Equivalence and Clinical Utility of Spanish and English Versions of a Diabetes Questionnaire: A Pilot Study.

    Science.gov (United States)

    Gerber, Ben; Smith, Everett V., Jr.; Girotti, Mariela; Pelaez, Lourdes; Lawless, Kimberly; Smolin, Louanne; Brodsky, Irwin; Eiser, Arnold

    2002-01-01

    Used Rasch measurement to study the psychometric properties of data obtained from a newly developed Diabetes Questionnaire designed to measure diabetes knowledge, attitudes, and self-care. Responses of 26 diabetes patients to the English version of the questionnaire and 24 patients to the Spanish version support the cross-form equivalence and…

  9. Latent trait standardization of the benzodiazepine dependence self-report questionnaire using the Rasch scaling model.

    NARCIS (Netherlands)

    Kan, C.C.; Ven, A.H.G.S. van der; Breteler, M.H.M.; Zitman, F.G.

    2001-01-01

    The aim of the present study was to obtain standardized scores that correspond with the raw scores on the four Rasch scales of the Benzodiazepine Dependence-Self Report Questionnaire (Bendep-SRQ). The eligible normative group for standardization of the Bendep-SRQ scales consisted of 217 general

  10. Latent Trait Standardization of the Benzodiazepine Dependence Self-Report Questionnaire using the Rasch Scaling Model

    NARCIS (Netherlands)

    Kan, C.C.; Ven, A.H.G.S. van der; Breteler, M.H.M.; Zitman, F.G.

    2001-01-01

    The aim of the present study was to obtain standardized scores that correspond with the raw scores on the four Rasch scales of the Benzodiazepine Dependence-Self Report Questionnaire (Bendep-SRQ). The eligible normative group for standardization of the Bendep-SRQ scales consisted of 217 general

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

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    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.

  12. "The Role of the Unit in Physics and Psychometrics" by Stephen Humphry--One Small Step for the Rasch Model, but Possibly One Giant Leap for Measurement in the Social Sciences

    Science.gov (United States)

    Salzberger, Thomas

    2011-01-01

    Compared to traditional test theory, where person measures are typically referenced to the distribution of a population, item response theory allows for a much more meaningful interpretation of measures as they can be directly compared to item locations. However, Stephen Humphry shows that the crucial role of the unit of measurement has been…

  13. 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…

  14. Validity of the Neuromuscular Recovery Scale: a measurement model approach.

    Science.gov (United States)

    Velozo, Craig; Moorhouse, Michael; Ardolino, Elizabeth; Lorenz, Doug; Suter, Sarah; Basso, D Michele; Behrman, Andrea L

    2015-08-01

    To determine how well the Neuromuscular Recovery Scale (NRS) items fit the Rasch, 1-parameter, partial-credit measurement model. Confirmatory factor analysis (CFA) and principal components analysis (PCA) of residuals were used to determine dimensionality. The Rasch, 1-parameter, partial-credit rating scale model was used to determine rating scale structure, person/item fit, point-measure item correlations, item discrimination, and measurement precision. Seven NeuroRecovery Network clinical sites. Outpatients (N=188) with spinal cord injury. Not applicable. NRS. While the NRS met 1 of 3 CFA criteria, the PCA revealed that the Rasch measurement dimension explained 76.9% of the variance. Ten of 11 items and 91% of the patients fit the Rasch model, with 9 of 11 items showing high discrimination. Sixty-nine percent of the ratings met criteria. The items showed a logical item-difficulty order, with Stand retraining as the easiest item and Walking as the most challenging item. The NRS showed no ceiling or floor effects and separated the sample into almost 5 statistically distinct strata; individuals with an American Spinal Injury Association Impairment Scale (AIS) D classification showed the most ability, and those with an AIS A classification showed the least ability. Items not meeting the rating scale criteria appear to be related to the low frequency counts. The NRS met many of the Rasch model criteria for construct validity. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  15. Fitting a Mixture Rasch Model to English as a Foreign Language Listening Tests: The Role of Cognitive and Background Variables in Explaining Latent Differential Item Functioning

    Science.gov (United States)

    Aryadoust, Vahid

    2015-01-01

    The present study uses a mixture Rasch model to examine latent differential item functioning in English as a foreign language listening tests. Participants (n = 250) took a listening and lexico-grammatical test and completed the metacognitive awareness listening questionnaire comprising problem solving (PS), planning and evaluation (PE), mental…

  16. 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.

  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...... population. The response rate was 68.5%, and the sample reported here contained 1101 respondents: 578 women and 519 men (four respondents did not indicate their genders). RESULTS: Each of the four domains of the WHOQOL-BREF scale fitted a two-parameter IRT model, but did not fit the Rasch model. Due...

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

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    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.Keywords: Perceived Understanding, Probability Concepts, Rasch Measurement Model DOI: dx.doi.org/10.22342/jme.61.1

  19. Rasch models suggested the satisfactory psychometric properties of the World Health Organization Quality of Life-Brief among lung cancer patients.

    Science.gov (United States)

    Lin, Chung-Ying; Yang, Szu-Chun; Lai, Wu-Wei; Su, Wu-Chou; Wang, Jung-Der

    2017-03-01

    The study examined whether the items of the World Health Organization Quality of Life-Brief questionnaire can assess its four underlying domains (Physical, Psychological, Social, and Environment) in a sample of lung cancer patients. All patients ( n = 1150) were recruited from a medical center in Tainan, and each participant completed the World Health Organization Quality of Life-Brief. Several Rasch rating scale models were used to examine the data-model fit, and Rasch analyses corroborated that each domain of the World Health Organization Quality of Life-Brief could be unidimensional. Although three items were found to have a poor fit, all the other items fit the unidimensionality with ordered thresholds.

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

    NARCIS (Netherlands)

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

    2017-01-01

    Objective: 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. Study

  1. Using Rasch Measurement for the Development and Use of Affective Assessments in Science Education Research

    Science.gov (United States)

    Sondergeld, Toni A.; Johnson, Carla C.

    2014-01-01

    With the demand for quality quantitative instruments in the field of science education rising, additional measures of currently unassessed affective variables need to be constructed. In this study, we discuss the survey creation and evaluation process of the STEM Awareness Community Survey (SACS) through an application of Liu's (Liu, X.,…

  2. 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…

  3. Rasch Measurement Analysis of a 25-Item Version of the Mueller/McCloskey Nurse Job Satisfaction Scale in a Sample of Nurses in Lebanon and Qatar

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    Michael Clinton

    2015-06-01

    Full Text Available The Mueller/McCloskey Nurse Job Satisfaction Scale (MMSS is widely used, but its psychometric characteristics have not been sufficiently validated for use in Middle Eastern countries. The objective of our methodological study was to determine the psychometric suitability of a 25-item version of the MMSS (MMSS-25 for use in middle-income and high-income Middle Eastern countries. A total of 1,322 registered nurses, 859 in Lebanon and 463 in Qatar, completed the MMSS-25 as part of a cross-sectional multinational investigation of nursing shortages in the region. We used the Rasch rating scale model to investigate the psychometric performance of the MMSS-25. We identified possible item bias among MMSS-25 items. We conducted confirmatory factor analyses (CFA to compare the fit to our data of five factor structures reported in the literature. We concluded that irrespective of administration in English or Arabic, the MMSS-25 is not sufficiently productive of measurement for use in the region. A core set of 13 items (MMSS-13, Cronbach’s α = .82 loading on five dimensions eliminates redundant MMSS items and is suitable for initial screening of nurses’ satisfaction. Of the five factor structures we examined, the MMSS-13 was the only close fit to our data (comparative fit index = 0.951; Tucker–Lewis index = 0.931; root mean square error of approximation = 0.051; p value = .401. The MMSS-13 has psychometric characteristics superior to MMSS-25, but additional items are required to meet the research-specific objectives of future studies of nurses’ job satisfaction in Middle Eastern countries.

  4. 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.

  5. A Rasch and factor analysis of the Functional Assessment of Cancer Therapy-General (FACT-G

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    Selby Peter J

    2007-04-01

    Full Text Available Abstract Background Although the Functional Assessment of Cancer Therapy – General questionnaire (FACT-G has been validated few studies have explored the factor structure of the instrument, in particular using non-sample dependent measurement techniques, such as Rasch Models. Furthermore, few studies have explored the relationship between item fit to the Rasch Model and clinical utility. The aim of this study was to investigate the dimensionality and measurement properties of the FACT-G with Rasch Models and Factor analysis. Methods A factor analysis and Rasch analysis (Partial Credit Model was carried out on the FACT-G completed by a heterogeneous sample of cancer patients (n = 465. For the Rasch analysis item fit (infit mean squares ≥ 1.30, dimensionality and item invariance were assessed. The impact of removing misfitting items on the clinical utility of the subscales and FACT-G total scale was also assessed. Results The factor analysis demonstrated a four factor structure of the FACT-G which broadly corresponded to the four subscales of the instrument. Internal consistency for these four scales was very good (Cronbach's alpha 0.72 – 0.85. The Rasch analysis demonstrated that each of the subscales and the FACT-G total scale had misfitting items (infit means square ≥ 1.30. All these scales with the exception of the Social & Family Well-being Scale (SFWB were unidimensional. When misfitting items were removed, the effect sizes and the clinical utility of the instrument were maintained for the subscales and the total FACT-G scores. Conclusion The results of the traditional factor analysis and Rasch analysis of the FACT-G broadly agreed. Caution should be exercised when utilising the Social & Family Well-being scale and further work is required to determine whether this scale is best represented by two factors. Additionally, removing misfitting items from scales should be performed alongside an assessment of the impact on clinical utility.

  6. Early career burnout among Dutch nurses : A process captured in a Rasch model

    NARCIS (Netherlands)

    de Vos, Jan Alexander; Brouwers, Andre; Schoot, Tineke; Pat-El, Ron; Verboon, Peter; Näring, Gerard

    2016-01-01

    This study investigates burnout among Dutch nursing graduates as a process by testing a sequential-developmental model. A sample of 237 respondents was recruited from a population of Dutch early career nurses. Burnout was measured with the Dutch version of the Maslach Burnout Inventory Human

  7. Early career burnout among Dutch nurses: A process captured in a Rasch model

    NARCIS (Netherlands)

    Vos, J.A. de; Brouwers, A.; Schoot, T.; Pat-El, R.; Verboon, P.; Näring, G.W.B.

    2016-01-01

    This study investigates burnout among Dutch nursing graduates as a process by testing a sequential-developmental model. A sample of 237 respondents was recruited from a population of Dutch early career nurses. Burnout was measured with the Dutch version of the Maslach Burnout Inventory Human

  8. Construct validity in Operations Management by using Rasch Measurement Theory. The case of the construct “motivation to implement continuous improvement"

    Directory of Open Access Journals (Sweden)

    Lidia Sanchez-Ruiz

    2016-12-01

    Full Text Available Construct design and validation is a common practise in the Operations Management field. In this sense, the aim of this study is to present Rasch Measurement Theory (RMT as richful and useful methodology in order to validate constructs. In order to do so, the measurement controversy in the social science is presented; then, RMT is explained as a solution for this measurement issue; after that, the different applications of RMT are described and, finally, the different stages of the validation process are presented. Thus, this work aims to serve as a guide for those researchers interested in the methodology. Therefore, a specific case is included: the validation of the construct “motivation to implement continuous improvement”.

  9. 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…

  10. 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

    quantifying the rater variation as a suitable measure of the variation of the rater odds ratios. An important example that will serve to motivate and illustrate the proposed model, is the study of Umbilical artery Doppler velocimetry used by obstetricians to assess the status of a foetus. The purpose...... of the assessment is to improve the foetus' chance of survival by choosing the optimal time of elective delivery. In the study, data related to 139 perinatal deaths were sent to 32 experts who were asked whether the use of Doppler velocimetry might have prevented each death....

  11. A Comparison between Discrimination Indices and Item-Response Theory Using the Rasch Model in a Clinical Course Written Examination of a Medical School.

    Science.gov (United States)

    Park, Jong Cook; Kim, Kwang Sig

    2012-03-01

    The reliability of test is determined by each items' characteristics. Item analysis is achieved by classical test theory and item response theory. The purpose of the study was to compare the discrimination indices with item response theory using the Rasch model. Thirty-one 4th-year medical school students participated in the clinical course written examination, which included 22 A-type items and 3 R-type items. Point biserial correlation coefficient (C(pbs)) was compared to method of extreme group (D), biserial correlation coefficient (C(bs)), item-total correlation coefficient (C(it)), and corrected item-total correlation coeffcient (C(cit)). Rasch model was applied to estimate item difficulty and examinee's ability and to calculate item fit statistics using joint maximum likelihood. Explanatory power (r2) of Cpbs is decreased in the following order: C(cit) (1.00), C(it) (0.99), C(bs) (0.94), and D (0.45). The ranges of difficulty logit and standard error and ability logit and standard error were -0.82 to 0.80 and 0.37 to 0.76, -3.69 to 3.19 and 0.45 to 1.03, respectively. Item 9 and 23 have outfit > or =1.3. Student 1, 5, 7, 18, 26, 30, and 32 have fit > or =1.3. C(pbs), C(cit), and C(it) are good discrimination parameters. Rasch model can estimate item difficulty parameter and examinee's ability parameter with standard error. The fit statistics can identify bad items and unpredictable examinee's responses.

  12. Comparison of CTT and Rasch-based approaches for the analysis of longitudinal Patient Reported Outcomes.

    Science.gov (United States)

    Blanchin, Myriam; Hardouin, Jean-Benoit; Le Neel, Tanguy; Kubis, Gildas; Blanchard, Claire; Mirallié, Eric; Sébille, Véronique

    2011-04-15

    Health sciences frequently deal with Patient Reported Outcomes (PRO) data for the evaluation of concepts, in particular health-related quality of life, which cannot be directly measured and are often called latent variables. Two approaches are commonly used for the analysis of such data: Classical Test Theory (CTT) and Item Response Theory (IRT). Longitudinal data are often collected to analyze the evolution of an outcome over time. The most adequate strategy to analyze longitudinal latent variables, which can be either based on CTT or IRT models, remains to be identified. This strategy must take into account the latent characteristic of what PROs are intended to measure as well as the specificity of longitudinal designs. A simple and widely used IRT model is the Rasch model. The purpose of our study was to compare CTT and Rasch-based approaches to analyze longitudinal PRO data regarding type I error, power, and time effect estimation bias. Four methods were compared: the Score and Mixed models (SM) method based on the CTT approach, the Rasch and Mixed models (RM), the Plausible Values (PV), and the Longitudinal Rasch model (LRM) methods all based on the Rasch model. All methods have shown comparable results in terms of type I error, all close to 5 per cent. LRM and SM methods presented comparable power and unbiased time effect estimations, whereas RM and PV methods showed low power and biased time effect estimations. This suggests that RM and PV methods should be avoided to analyze longitudinal latent variables. Copyright © 2010 John Wiley & Sons, Ltd.

  13. A Comparison of Graded Response and Rasch Partial Credit Models with Subjective Well-Being.

    Science.gov (United States)

    Baker, John G.; Rounds, James B.; Zevon, Michael A.

    2000-01-01

    Compared two multiple category item response theory models using a data set of 52 mood terms with 713 undergraduate psychology students. Comparative model fit for the Samejima (F. Samejima, 1966) logistic model for graded responses and the Masters (G. Masters, 1982) partial credit model favored the former model for this data set. (SLD)

  14. Patient self-report section of the ASES questionnaire: a Spanish validation study using classical test theory and the Rasch model.

    Science.gov (United States)

    Vrotsou, Kalliopi; Cuéllar, Ricardo; Silió, Félix; Rodriguez, Miguel Ángel; Garay, Daniel; Busto, Gorka; Trancho, Ziortza; Escobar, Antonio

    2016-10-18

    The aim of the current study was to validate the self-report section of the American Shoulder and Elbow Surgeons questionnaire (ASES-p) into Spanish. Shoulder pathology patients were recruited and followed up to 6 months post treatment. The ASES-p, Constant, SF-36 and Barthel scales were filled-in pre and post treatment. Reliability was tested with Cronbach's alpha, convergent validity with Spearman's correlations coefficients. Confirmatory factor analysis (CFA) and the Rasch model were implemented for assessing structural validity and unidimensionality of the scale. Models with and without the pain item were considered. Responsiveness to change was explored via standardised effect sizes. Results were acceptable for both tested models. Cronbach's alpha was 0.91, total scale correlations with Constant and physical SF-36 dimensions were >0.50. Factor loadings for CFA were >0.40. The Rasch model confirmed unidimensionality of the scale, even though item 10 "do usual sport" was suggested as non-informative. Finally, patients with improved post treatment shoulder function and those receiving surgery had higher standardised effect sizes. The adapted Spanish ASES-p version is a valid and reliable tool for shoulder evaluation and its unidimensionality is supported by the data.

  15. The construct validity of the Major Depression Inventory: A Rasch analysis of a self-rating scale in primary care.

    Science.gov (United States)

    Nielsen, Marie Germund; Ørnbøl, Eva; Vestergaard, Mogens; Bech, Per; Christensen, Kaj Sparle

    2017-06-01

    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. 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 and scalability. Our Rasch analysis showed misfit concerning the sleep and appetite items (items 9 and 10). The response categories were disordered for eight items. After modifying the original six-point to a four-point scoring system for all items, we achieved ordered response categories for all ten items. The person separation reliability was acceptable (0.82) for the initial model. Dimensionality testing did not support combining the ten items to create a total score. The scale appeared to be well targeted to this clinical sample. No significant differential item functioning was observed 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. Our study indicated scalability problems in the current version of the Major Depression Inventory. The conducted analysis revealed better statistical fit when items 9 and 10 were excluded. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Using classical test theory, item response theory, and Rasch measurement theory to evaluate patient-reported outcome measures: a comparison of worked examples.

    Science.gov (United States)

    Petrillo, Jennifer; Cano, Stefan J; McLeod, Lori D; Coon, Cheryl D

    2015-01-01

    To provide comparisons and a worked example of item- and scale-level evaluations based on three psychometric methods used in patient-reported outcome development-classical test theory (CTT), item response theory (IRT), and Rasch measurement theory (RMT)-in an analysis of the National Eye Institute Visual Functioning Questionnaire (VFQ-25). Baseline VFQ-25 data from 240 participants with diabetic macular edema from a randomized, double-masked, multicenter clinical trial were used to evaluate the VFQ at the total score level. CTT, RMT, and IRT evaluations were conducted, and results were assessed in a head-to-head comparison. Results were similar across the three methods, with IRT and RMT providing more detailed diagnostic information on how to improve the scale. CTT led to the identification of two problematic items that threaten the validity of the overall scale score, sets of redundant items, and skewed response categories. IRT and RMT additionally identified poor fit for one item, many locally dependent items, poor targeting, and disordering of over half the response categories. Selection of a psychometric approach depends on many factors. Researchers should justify their evaluation method and consider the intended audience. If the instrument is being developed for descriptive purposes and on a restricted budget, a cursory examination of the CTT-based psychometric properties may be all that is possible. In a high-stakes situation, such as the development of a patient-reported outcome instrument for consideration in pharmaceutical labeling, however, a thorough psychometric evaluation including IRT or RMT should be considered, with final item-level decisions made on the basis of both quantitative and qualitative results. Copyright © 2015. Published by Elsevier Inc.

  17. Assessing social isolation in motor neurone disease: a Rasch analysis of the MND Social Withdrawal Scale.

    Science.gov (United States)

    Gibbons, Chris J; Thornton, Everard W; Ealing, John; Shaw, Pamela J; Talbot, Kevin; Tennant, Alan; Young, Carolyn A

    2013-11-15

    Social withdrawal is described as the condition in which an individual experiences a desire to make social contact, but is unable to satisfy that desire. It is an important issue for patients with motor neurone disease who are likely to experience severe physical impairment. This study aims to reassess the psychometric and scaling properties of the MND Social Withdrawal Scale (MND-SWS) domains and examine the feasibility of a summary scale, by applying scale data to the Rasch model. The MND Social Withdrawal Scale was administered to 298 patients with a diagnosis of MND, alongside the Hospital Anxiety and Depression Scale. The factor structure of the MND Social Withdrawal Scale was assessed using confirmatory factor analysis. Model fit, category threshold analysis, differential item functioning (DIF), dimensionality and local dependency were evaluated. Factor analysis confirmed the suitability of the four-factor solution suggested by the original authors. Mokken scale analysis suggested the removal of item five. Rasch analysis removed a further three items; from the Community (one item) and Emotional (two items) withdrawal subscales. Following item reduction, each scale exhibited excellent fit to the Rasch model. A 14-item Summary scale was shown to fit the Rasch model after subtesting the items into three subtests corresponding to the Community, Family and Emotional subscales, indicating that items from these three subscales could be summed together to create a total measure for social withdrawal. Removal of four items from the Social Withdrawal Scale led to a four factor solution with a 14-item hierarchical Summary scale that were all unidimensional, free for DIF and well fitted to the Rasch model. The scale is reliable and allows clinicians and researchers to measure social withdrawal in MND along a unidimensional construct. © 2013. Published by Elsevier B.V. All rights reserved.

  18. 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.

  19. 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.

  20. 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…

  1. Rasch-Master's Partial Credit Model in the assessment of children's creativity in drawings.

    Science.gov (United States)

    Nakano, Tatiana de Cássia; Primi, Ricardo

    2014-01-01

    The purpose of the present study was to use the Partial Credit Model to study the factors of the Test of Creativity in Children and identify which characteristics of the creative person would be more effective to differentiate subjects according to their ability level. A sample of 1426 students from first to eighth grades answered the instrument. The Partial Credits model was used to estimate the ability of the subjects and item difficulties on a common scale for each of the four factors, indicating which items required a higher level of creativity to be scored and will differentiate the more creative individuals. The results demonstrated that the greater part of the characteristics showed good fit indices, with values between 0.80 and 1.30 both infit and outfit, indicating a response pattern consistent with the model. The characteristics of Unusual Perspective, Expression of Emotion and Originality have been identified as better predictors of creative performance because requires greater ability level (usually above two standard deviation). These results may be used in the future development of an instrument's reduced form or simplification of the current correction model.

  2. 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.

  3. Rasch Analysis of the Bruininks-Oseretsky Test of Motor Proficiency--Second Edition in Intellectual Disabilities

    Science.gov (United States)

    Wuang, Yee-Pay; Lin, Yueh-Hsien; Su, Chwen-Yng

    2009-01-01

    The Bruininks-Oseretsky Test of Motor Proficiency-Second Edition (BOT-2) is widely used to assess motor skills for both clinical and research purposes; however, its validity has not been adequately assessed in intellectual disabilities (ID). This study used partial credit Rasch model to examine the measurement properties of the BOT-2 among 446…

  4. 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.

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

    DEFF Research Database (Denmark)

    Andersen, Martin Stolpe; Nielsen, Tine

    subscales measuring Extrinsic Motivation (EM) and one scale measuring Amotivation (AM), each with 4 items. The AMS was translated into Danish and data was collected from psychology students (N = 607) at two Danish universities in 6 different study terms. The construct validity of the seven scales was first...... 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...

  6. Analyzing Process Quality of Early Childhood Education with Many Facet Rash Measurement Model

    Science.gov (United States)

    Basturk, Ramazan; Isikoglu, Nesrin

    2008-01-01

    Quality of early childhood education institutions specifically, dimensions of process quality should be evaluated. Purpose of this study is to analyze process quality of early childhood education by using many-facet Rasch measurement model (MFRM). In this study, data were collected from twelve early childhood education institutions by four…

  7. Rasch measurement analysis of the Mayo-Portland Adaptability Inventory (MPAI-4) in a community-based rehabilitation sample.

    Science.gov (United States)

    Kean, Jacob; Malec, James F; Altman, Irwin M; Swick, Shannon

    2011-05-01

    The precise measurement of patient outcomes depends upon clearly articulated constructs and refined clinical assessment instruments that work equally well for all subgroups within a population. This is a challenging task in those with acquired brain injury (ABI) because of the marked heterogeneity of the disorder and subsequent outcomes. Although essential, the iterative process of instrument refinement is often neglected. This present study was undertaken to examine validity, reliability, dimensionality and item estimate invariance of the Mayo-Portland Adaptability Inventory - 4 (MPAI-4), an outcome measure for persons with ABI. The sampled population included 603 persons with traumatic ABI participating in a home- and community-based rehabilitation program. Results indicated that the MPAI-4 is a valid, reliable measure of outcome following traumatic ABI, which measures a broad but unitary core construct of outcome after ABI. Further, the MPAI-4 is composed of items that are unbiased toward selected subgroups except where differences could be expected [e.g., more chronic traumatic brain injury (TBI) patients are better able to negotiate demands of transportation than more acute TBI patients]. We address the trade-offs between strict unidimensionality and clinical applicability in measuring outcome, and illustrate the advantages and disadvantages of applying single-parameter measurement models to broad constructs.

  8. Rasch-built Overall Disability Scale for patients with chemotherapy-induced peripheral neuropathy (CIPN-R-ODS).

    Science.gov (United States)

    Binda, D; Vanhoutte, E K; Cavaletti, G; Cornblath, D R; Postma, T J; Frigeni, B; Alberti, P; Bruna, J; Velasco, R; Argyriou, A A; Kalofonos, H P; Psimaras, D; Ricard, D; Pace, A; Galiè, E; Briani, C; Dalla Torre, C; Lalisang, R I; Boogerd, W; Brandsma, D; Koeppen, S; Hense, J; Storey, D; Kerrigan, S; Schenone, A; Fabbri, S; Rossi, E; Valsecchi, M G; Faber, C G; Merkies, I S J; Galimberti, S; Lanzani, F; Mattavelli, L; Piatti, M L; Bidoli, P; Cazzaniga, M; Cortinovis, D; Lucchetta, M; Campagnolo, M; Bakkers, M; Brouwer, B; Boogerd, W; Grant, R; Reni, L; Piras, B; Pessino, A; Padua, L; Granata, G; Leandri, M; Ghignotti, I; Plasmati, R; Pastorelli, F; Heimans, J J; Eurelings, M; Meijer, R J; Grisold, W; Lindeck Pozza, E; Mazzeo, A; Toscano, A; Russo, M; Tomasello, C; Altavilla, G; Penas Prado, M; Dominguez Gonzalez, C; Dorsey, S G

    2013-09-01

    Chemotherapy-induced peripheral neuropathy (CIPN) is a common neurological side-effect of cancer treatment and may lead to declines in patients' daily functioning and quality of life. To date, there are no modern clinimetrically well-evaluated outcome measures available to assess disability in CIPN patients. The objective of the study was to develop an interval-weighted scale to capture activity limitations and participation restrictions in CIPN patients using the Rasch methodology and to determine its validity and reliability properties. A preliminary Rasch-built Overall Disability Scale (pre-R-ODS) comprising 146 items was assessed twice (interval: 2-3 weeks; test-retest reliability) in 281 CIPN patients with a stable clinical condition. The obtained data were subjected to Rasch analyses to determine whether model expectations would be met, and if necessarily, adaptations were made to obtain proper model fit (internal validity). External validity was obtained by correlating the CIPN-R-ODS with the National Cancer Institute-Common Toxicity Criteria (NCI-CTC) neuropathy scales and the Pain-Intensity Numeric-Rating-Scale (PI-NRS). The preliminary R-ODS did not meet Rasch model's expectations. Items displaying misfit statistics, disordered thresholds, item bias or local dependency were systematically removed. The final CIPN-R-ODS consisting of 28 items fulfilled all the model's expectations with proper validity and reliability, and was unidimensional. The final CIPN-R-ODS is a Rasch-built disease-specific, interval measure suitable to detect disability in CIPN patients and bypasses the shortcomings of classical test theory ordinal-based measures. Its use is recommended in future clinical trials in CIPN. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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

  10. 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.

  11. Rasch Analysis of the Locus-of-Hope Scale. Brief Report

    Science.gov (United States)

    Gadiana, Leny G.; David, Adonis P.

    2015-01-01

    The Locus-of-Hope Scale (LHS) was developed as a measure of the locus-of-hope dimensions (Bernardo, 2010). The present study adds to the emerging literature on locus-of-hope by assessing the psychometric properties of the LHS using Rasch analysis. The results from the Rasch analyses of the four subscales of LHS provided evidence on the…

  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. 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.

  14. Rasch-built Overall Disability Scale (R-ODS) for immune-mediated peripheral neuropathies.

    Science.gov (United States)

    van Nes, S I; Vanhoutte, E K; van Doorn, P A; Hermans, M; Bakkers, M; Kuitwaard, K; Faber, C G; Merkies, I S J

    2011-01-25

    To develop a patient-based, linearly weighted scale that captures activity and social participation limitations in patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and gammopathy-related polyneuropathy (MGUSP). A preliminary Rasch-built Overall Disability Scale (R-ODS) containing 146 activity and participation items was constructed, based on the WHO International Classification of Functioning, Disability and Health, literature search, and patient interviews. The preliminary R-ODS was assessed twice (interval: 2-4 weeks; test-retest reliability studies) in 294 patients who experienced GBS in the past (n = 174) or currently have stable CIDP (n = 80) or MGUSP (n = 40). Data were analyzed using the Rasch unidimensional measurement model (RUMM2020). The preliminary R-ODS did not meet the Rasch model expectations. Based on disordered thresholds, misfit statistics, item bias, and local dependency, items were systematically removed to improve the model fit, regularly controlling the class intervals and model statistics. Finally, we succeeded in constructing a 24-item scale that fulfilled all Rasch requirements. "Reading a newspaper/book" and "eating" were the 2 easiest items; "standing for hours" and "running" were the most difficult ones. Good validity and reliability were obtained. The R-ODS is a linearly weighted scale that specifically captures activity and social participation limitations in patients with GBS, CIDP, and MGUSP. Compared to the Overall Disability Sum Score, the R-ODS represents a wider range of item difficulties, thereby better targeting patients with different ability levels. If responsive, the R-ODS will be valuable for future clinical trials and follow-up studies in these conditions.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Application of Rasch analysis to the parent adherence report questionnaire in juvenile idiopathic arthritis.

    Science.gov (United States)

    Toupin April, Karine; Higgins, Johanne; Ehrmann Feldman, Debbie

    2016-07-28

    Adherence to treatment in children with juvenile idiopathic arthritis (JIA) is associated with better outcomes. Assessing patient adherence in JIA, as well as attitudes and beliefs about prescribed treatments, is important for the clinician in order to optimize patient management. The objective of the current study was to evaluate the psychometric properties of the Parent (proxy-report) Adherence Report Questionnaires (PARQ), which assesses beliefs and behaviors related to adherence to treatments prescribed for JIA. A Rasch analysis was conducted on data collected with parents of children with JIA from two studies in which the PARQ was used as a measure of adherence. The PARQ showed preliminary evidence of multidimensionality with two factors, accounting for 38 % and 27 % of the variance respectively. The PARQ in its original version does not adhere to expectations of the Rasch model. A transformed version of the PARQ obtained by deletion of the general adherence scale and modification of visual analog scales into 5-point likert scales improved fit to the model and showed preliminary evidence of unidimensionality. The PARQ was transformed based on the results of the Rasch analysis. The transformed version of the PARQ shows preliminary evidence of unidimensionality and may allow computation of a total score, although further testing is needed to verify these findings.

  18. 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…

  19. 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

  20. The Number of Response Categories and the Reverse Directional Item Problem in Likert-Type Scales: A Study with the Rasch Model

    Directory of Open Access Journals (Sweden)

    Mustafa İLHAN

    2017-09-01

    Full Text Available This study addressed reverse directional item and the number of response categories problems in Likert-type scales. The Fear of Negative Evaluation Scale (FNES and the Oxford Happiness Questionnaire (OHQ were used as data collection tools. The data of the study were analyzed according to the Rasch model. The analysis found that the observed and expected test characteristic curves were largely overlapped, each of the three rating scales worked effectively, and the differences between response categories could be distinguished successfully by the participants in straightforward directional items. On the other hand, it was determined that there were significant differences between the observed and expected test characteristic curves in reverse directional items. It was also found that no matter which one of these three, five and seven-point rating scales was used, the participants could not distinguish the response categories of the reverse directional items on the FNES and the OHQ. Afterwards, the reverse directional items were removed from the data file, and the analysis was repeated. The analysis results revealed that item discrimination, reliability coefficients for person facet, separation ratios and Chi square values calculated for the facets of person and items were higher in five-pointed rating compared to three and seven pointed rating.

  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. Rasch Measurement Analysis of the Mayo-Portland Adaptability Inventory (MPAI-4) in a Community-Based Rehabilitation Sample

    OpenAIRE

    Kean, Jacob; Malec, James F.; Altman, Irwin M.; Swick, Shannon

    2011-01-01

    The precise measurement of patient outcomes depends upon clearly articulated constructs and refined clinical assessment instruments that work equally well for all subgroups within a population. This is a challenging task in those with acquired brain injury (ABI) because of the marked heterogeneity of the disorder and subsequent outcomes. Alhough essential, the iterative process of instrument refinement is often neglected. This present study was undertaken to examine validity, reliability, dim...

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

    Science.gov (United States)

    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…

  4. 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

  5. A generalized measurement model to quantify health: the multi-attribute preference response model.

    Science.gov (United States)

    Krabbe, Paul F M

    2013-01-01

    After 40 years of deriving metric values for health status or health-related quality of life, the effective quantification of subjective health outcomes is still a challenge. Here, two of the best measurement tools, the discrete choice and the Rasch model, are combined to create a new model for deriving health values. First, existing techniques to value health states are briefly discussed followed by a reflection on the recent revival of interest in patients' experience with regard to their possible role in health measurement. Subsequently, three basic principles for valid health measurement are reviewed, namely unidimensionality, interval level, and invariance. In the main section, the basic operation of measurement is then discussed in the framework of probabilistic discrete choice analysis (random utility model) and the psychometric Rasch model. It is then shown how combining the main features of these two models yields an integrated measurement model, called the multi-attribute preference response (MAPR) model, which is introduced here. This new model transforms subjective individual rank data into a metric scale using responses from patients who have experienced certain health states. Its measurement mechanism largely prevents biases such as adaptation and coping. Several extensions of the MAPR model are presented. The MAPR model can be applied to a wide range of research problems. If extended with the self-selection of relevant health domains for the individual patient, this model will be more valid than existing valuation techniques.

  6. Improving the Individual Work Performance Questionnaire using Rasch analysis.

    OpenAIRE

    Koopmans, L.; Bernaards, C.M.; Hildebrandt, V.H.; Buuren, S. van; Beek, A.J. van der; Vet, H.C.W. de

    2014-01-01

    Recently, the Individual Work Performance Questionnaire (IWPQ) version 0.2 was developed using Rasch analysis. The goal of the current study was to improve targeting of the IWPQ scales by including additional items. The IWPQ 0.2 (original) and 0.3 (including additional items) were examined using Rasch analysis. Additional items that showed misfit or did not improve targeting were removed from the IWPQ 0.3, resulting in a final IWPQ 1.0. Subsequently, the scales showed good model fit and relia...

  7. 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

  8. 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…

  9. 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.

  10. 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…

  11. 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.

  12. An Introduction to the Partial Credit Model for Developing Nursing Assessments.

    Science.gov (United States)

    Fox, Christine

    1999-01-01

    Demonstrates how the partial credit model, a variation of the Rasch Measurement Model, can be used to develop performance-based assessments for nursing education. Applies the model using the Practical Knowledge Inventory for Nurses. (SK)

  13. 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.

  14. A Cross-Cultural Validation of Stage Development: A Rasch Re-Analysis of Longitudinal Socio-Moral Reasoning Data

    Science.gov (United States)

    Boom, Jan; Wouters, Hans; Keller, Monika

    2007-01-01

    Kohlberg's characterization of moral development as displaying an invariant hierarchical order of structurally consistent stages is losing ground. However, by applying Rasch analysis, Dawson recently gave new interpretation and support to his characterization of stage development. Using Rasch models, we replicated and strengthened her findings in…

  15. 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.

  16. 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…

  17. Evaluation of the Edinburgh Post Natal Depression Scale using Rasch analysis

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    Tennant Alan

    2006-06-01

    Full Text Available Abstract Background The Edinburgh Postnatal Depression Scale (EPDS is a 10 item self-rating post-natal depression scale which has seen widespread use in epidemiological and clinical studies. Concern has been raised over the validity of the EPDS as a single summed scale, with suggestions that it measures two separate aspects, one of depressive feelings, the other of anxiety. Methods As part of a larger cross-sectional study conducted in Melbourne, Australia, a community sample (324 women, ranging in age from 18 to 44 years: mean = 32 yrs, SD = 4.6, was obtained by inviting primiparous women to participate voluntarily in this study. Data from the EPDS were fitted to the Rasch measurement model and tested for appropriate category ordering, for item bias through Differential Item Functioning (DIF analysis, and for unidimensionality through tests of the assumption of local independence. Results Rasch analysis of the data from the ten item scale initially demonstrated a lack of fit to the model with a significant Item-Trait Interaction total chi-square (chi Square = 82.8, df = 40; p Conclusion The results of this study suggest that EPDS, in its original 10 item form, is not a viable scale for the unidimensional measurement of depression. Rasch analysis suggests that a revised eight item version (EPDS-8 would provide a more psychometrically robust scale. The revised cut points of 7/8 and 9/10 for the EPDS-8 show high levels of agreement with the original case identification for the EPDS-10.

  18. 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.

  19. Development of an Upper Extremity Function Measurement Model.

    Science.gov (United States)

    Hong, Ickpyo; Simpson, Annie N; Li, Chih-Ying; Velozo, Craig A

    This study demonstrated the development of a measurement model for gross upper-extremity function (GUE). The dependent variable was the Rasch calibration of the 27 ICF-GUE test items. The predictors were object weight, lifting distance from floor, carrying, and lifting. Multiple regression was used to investigate the contribution that each independent variable makes to the model with 203 outpatients. Object weight and lifting distance were the only statistically and clinically significant independent variables in the model, accounting for 83% of the variance (p model indicates that, with each one pound increase in object weight, item challenge increases by 0.16 (p measurement model for the ICF-GUE can be explained by object weight and distance lifted from the floor.

  20. Rasch Analyses of Very Low Food Security among Households and Children in the Three City Study.

    Science.gov (United States)

    Moffitt, Robert A; Ribar, David C

    2016-04-01

    The longitudinal Three City Study of low-income families with children measures food hardships using fewer questions and some different questions from the standard U.S. instrument for measuring food security, the Household Food Security Survey Module (HFSSM) in the Current Population Survey (CPS). We utilize a Rasch measurement model to identify thresholds of very low food security among households and very low food security among children in the Three City Study that are comparable to thresholds from the HFSSM. We also use the Three City Study to empirically investigate the determinants of food insecurity and of these specific food insecurity outcomes, estimating a multivariate behavioral Rasch model that is adapted to address longitudinal data. The estimation results indicate that participation in the Supplemental Nutrition Assistance Program and the Temporary Assistance for Needy Families program reduce food insecurity, while poverty and disability among caregivers increase it. Besides its longitudinal structure, the Three City Study measures many more characteristics about households than the CPS. Our estimates reveal that financial assistance through social networks and a household's own financial assets reduce food insecurity, while its outstanding loans increase insecurity.

  1. Rasch Analyses of Very Low Food Security among Households and Children in the Three City Study*

    Science.gov (United States)

    Moffitt, Robert A.; Ribar, David C.

    2017-01-01

    The longitudinal Three City Study of low-income families with children measures food hardships using fewer questions and some different questions from the standard U.S. instrument for measuring food security, the Household Food Security Survey Module (HFSSM) in the Current Population Survey (CPS). We utilize a Rasch measurement model to identify thresholds of very low food security among households and very low food security among children in the Three City Study that are comparable to thresholds from the HFSSM. We also use the Three City Study to empirically investigate the determinants of food insecurity and of these specific food insecurity outcomes, estimating a multivariate behavioral Rasch model that is adapted to address longitudinal data. The estimation results indicate that participation in the Supplemental Nutrition Assistance Program and the Temporary Assistance for Needy Families program reduce food insecurity, while poverty and disability among caregivers increase it. Besides its longitudinal structure, the Three City Study measures many more characteristics about households than the CPS. Our estimates reveal that financial assistance through social networks and a household's own financial assets reduce food insecurity, while its outstanding loans increase insecurity. PMID:29187764

  2. A Mixture Rasch Model with a Covariate: A Simulation Study via Bayesian Markov Chain Monte Carlo Estimation

    Science.gov (United States)

    Dai, Yunyun

    2013-01-01

    Mixtures of item response theory (IRT) models have been proposed as a technique to explore response patterns in test data related to cognitive strategies, instructional sensitivity, and differential item functioning (DIF). Estimation proves challenging due to difficulties in identification and questions of effect size needed to recover underlying…

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Validation of VARK learning modalities questionnaire using Rasch analysis

    Science.gov (United States)

    Fitkov-Norris, E. D.; Yeghiazarian, A.

    2015-02-01

    This article discusses the application of Rasch analysis to assess the internal validity of a four sub-scale VARK (Visual, Auditory, Read/Write and Kinaesthetic) learning styles instrument. The results from the analysis show that the Rasch model fits the majority of the VARK questionnaire data and the sample data support the internal validity of the four sub-constructs at 1% level of significance for all but one item. While this suggests that the instrument could potentially be used as a predictor for a person's learning preference orientation, further analysis is necessary to confirm the invariability of the instrument across different user groups across factors such as gender, age, educational and cultural background.

  5. 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.

  6. Diagnosis of students' ability in a statistical course based on Rasch probabilistic outcome

    Science.gov (United States)

    Mahmud, Zamalia; Ramli, Wan Syahira Wan; Sapri, Shamsiah; Ahmad, Sanizah

    2017-06-01

    Measuring students' ability and performance are important in assessing how well students have learned and mastered the statistical courses. Any improvement in learning will depend on the student's approaches to learning, which are relevant to some factors of learning, namely assessment methods carrying out tasks consisting of quizzes, tests, assignment and final examination. This study has attempted an alternative approach to measure students' ability in an undergraduate statistical course based on the Rasch probabilistic model. Firstly, this study aims to explore the learning outcome patterns of students in a statistics course (Applied Probability and Statistics) based on an Entrance-Exit survey. This is followed by investigating students' perceived learning ability based on four Course Learning Outcomes (CLOs) and students' actual learning ability based on their final examination scores. Rasch analysis revealed that students perceived themselves as lacking the ability to understand about 95% of the statistics concepts at the beginning of the class but eventually they had a good understanding at the end of the 14 weeks class. In terms of students' performance in their final examination, their ability in understanding the topics varies at different probability values given the ability of the students and difficulty of the questions. Majority found the probability and counting rules topic to be the most difficult to learn.

  7. 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.

  8. Evaluation of the Edinburgh Post Natal Depression Scale using Rasch analysis

    Science.gov (United States)

    Pallant, Julie F; Miller, Renée L; Tennant, Alan

    2006-01-01

    Background The Edinburgh Postnatal Depression Scale (EPDS) is a 10 item self-rating post-natal depression scale which has seen widespread use in epidemiological and clinical studies. Concern has been raised over the validity of the EPDS as a single summed scale, with suggestions that it measures two separate aspects, one of depressive feelings, the other of anxiety. Methods As part of a larger cross-sectional study conducted in Melbourne, Australia, a community sample (324 women, ranging in age from 18 to 44 years: mean = 32 yrs, SD = 4.6), was obtained by inviting primiparous women to participate voluntarily in this study. Data from the EPDS were fitted to the Rasch measurement model and tested for appropriate category ordering, for item bias through Differential Item Functioning (DIF) analysis, and for unidimensionality through tests of the assumption of local independence. Results Rasch analysis of the data from the ten item scale initially demonstrated a lack of fit to the model with a significant Item-Trait Interaction total chi-square (chi Square = 82.8, df = 40; p < .001). Removal of two items (items 7 and 8) resulted in a non-significant Item-Trait Interaction total chi-square with a residual mean value for items of -0.467 with a standard deviation of 0.850, showing fit to the model. No DIF existed in the final 8-item scale (EPDS-8) and all items showed fit to model expectations. Principal Components Analysis of the residuals supported the local independence assumption, and unidimensionality of the revised EPDS-8 scale. Revised cut points were identified for EPDS-8 to maintain the case identification of the original scale. Conclusion The results of this study suggest that EPDS, in its original 10 item form, is not a viable scale for the unidimensional measurement of depression. Rasch analysis suggests that a revised eight item version (EPDS-8) would provide a more psychometrically robust scale. The revised cut points of 7/8 and 9/10 for the EPDS-8 show high

  9. 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

  10. 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.

  11. Rasch scaling paranormal belief and experience: structure and semantics of Thalbourne's Australian Sheep-Goat Scale.

    Science.gov (United States)

    Lange, Rense; Thalbourne, Michael A

    2002-12-01

    Research on the relation between demographic variables and paranormal belief remains controversial given the possible semantic distortions introduced by item and test level biases. We illustrate how Rasch scaling can be used to detect such biases and to quantify their effects, using the Australian Sheep-Goal Scale as a substantive example. Based on data from 1.822 respondents, this test was Rasch scalable, reliable, and unbiased at the test level. Consistent with other research in which unbiased measures of paranormal belief were used, extremely weak age and sex effects were found (partial eta2 = .005 and .012, respectively).

  12. 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

  13. 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…

  14. 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…

  15. The GAMMA® nursing measure: Its calibration for construct validity ...

    African Journals Online (AJOL)

    Purpose: To subject the GAMMA nursing measure to the Rasch Measurement Model and to report if the measure can function as an interval scale to provide metric measurements of patients' ability to perform instrumental activities of daily living. Method: A quantitative design was followed whereby GAMMA raw scores were ...

  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. The validity of a professional competence tool for physiotherapy students in simulation-based clinical education: a Rasch analysis.

    Science.gov (United States)

    Judd, Belinda K; Scanlan, Justin N; Alison, Jennifer A; Waters, Donna; Gordon, Christopher J

    2016-08-05

    Despite the recent widespread adoption of simulation in clinical education in physiotherapy, there is a lack of validated tools for assessment in this setting. The Assessment of Physiotherapy Practice (APP) is a comprehensive tool used in clinical placement settings in Australia to measure professional competence of physiotherapy students. The aim of the study was to evaluate the validity of the APP for student assessment in simulation settings. A total of 1260 APPs were collected, 971 from students in simulation and 289 from students in clinical placements. Rasch analysis was used to examine the construct validity of the APP tool in three different simulation assessment formats: longitudinal assessment over 1 week of simulation; longitudinal assessment over 2 weeks; and a short-form (25 min) assessment of a single simulation scenario. Comparison with APPs from 5 week clinical placements in hospital and clinic-based settings were also conducted. The APP demonstrated acceptable fit to the expectations of the Rasch model for the 1 and 2 week clinical simulations, exhibiting unidimensional properties that were able to distinguish different levels of student performance. For the short-form simulation, nine of the 20 items recorded greater than 25 % of scores as 'not-assessed' by clinical educators which impacted on the suitability of the APP tool in this simulation format. The APP was a valid assessment tool when used in longitudinal simulation formats. A revised APP may be required for assessment in short-form simulation scenarios.

  18. The BETA ® nursing measure: Calibrating construct validity with ...

    African Journals Online (AJOL)

    Background: The BETA nursing measure has been introduced as a tool to routinely measure and monitor the outcomes of patients' activities of daily living in a restorative nursing care context. Objectives: To investigate the BETA's construct validity using the Rasch model with specific reference to the BETA's potential to be ...

  19. Rasch Analysis of the Premature Ejaculation Diagnostic Tool (PEDT and the International Index of Erectile Function (IIEF in an Iranian Sample of Prostate Cancer Patients.

    Directory of Open Access Journals (Sweden)

    Chung-Ying Lin

    Full Text Available Male sexual dysfunction is an increasing problem across a variety of general and clinical populations, such as cancer populations; especially among prostate cancer patients who tend to receive treatments that often result in erectile dysfunction (ED and/or premature ejaculation (PE. Therefore, in order to diagnose ED and PE in these populations, adequate and efficient instruments such as the International Index of Erectile Function 5-item version (IIEF-5 and the Premature Ejaculation Diagnostic Tool (PEDT are needed. However, since this is an important topic additional evidence of psychometric properties of the IIEF-5 and the PEDT in such samples are required. Thus the aim of the present study was to use Rasch models to investigate the construct validity, local dependency, score order, and differential item functioning (DIF of both questionnaires in a sample of prostate cancer patients.Prostate cancer patients (n = 1058, mean±SD age = 64.07±6.84 years who visited urology clinics were invited to fill out the IIEF-5 and the PEDT. Construct validity was examined using infit and outfit mean square (MnSq and local dependency using correlations between each two residual Rasch scores. Score order was investigated using step and average measures of difficulty and DIF using DIF contrast.All IIEF-5 and PEDT items had acceptable infit and outfit MnSq. Step measures revealed that all but two items had disordered categories in terms of scores 1 to 3. Only one local dependency was found, and no items displayed DIF across age, educational level, and help seeking.The results showed that both the IIEF-5 and the PEDT had sound psychometric properties in the Rasch analyses, although some score disordering could be detected in both instruments. The results of no DIF items in both instruments suggest using them to compare ED and PE across age and educational level is adequate.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  2. Development of a Performance-Based Measure of Executive Functions in Patients with Schizophrenia.

    Directory of Open Access Journals (Sweden)

    En-Chi Chiu

    Full Text Available A performance-based measure for assessing executive functions (EF is useful to understand patients' real life performance of EF. This study aimed to develop a performance-based measure of executive functions (PEF based on the Lezak model and to examine psychometric properties (i.e., unidimensionality and reliability of the PEF using Rasch analysis in patients with schizophrenia. We developed the PEF in three phases: (1 designing the preliminary version of PEF; (2 consultation with experts, cognitive interviews with patients, and pilot tests on patients to revise the preliminary PEF; (3 establishment of the final version of the PEF and examination of unidimensionality and Rasch reliability. Two hundred patients were assessed using the revised PEF. After deleting items which did not satisfy the Rasch model's expectations, the final version of the PEF contained 1 practice item and 13 test items for assessing the four domains of EF (i.e., volition, planning, purposive action, and effective performance. For unidimensional and multidimensional Rasch analyses, the 4 domains showed good reliability (i.e., 0.77-0.85 and 0.87-0.90, respectively. Our results showed that the PEF had satisfactory unidimensionality and Rasch reliability. Therefore, clinicians and researchers could use the PEF to assess the four domains of EF in patients with schizophrenia.

  3. Rasch-ionale for neurologists

    NARCIS (Netherlands)

    Vanhoutte, Els K.; Hermans, Mieke C. E.; Faber, Catharina G.; Gorson, Kenneth C.; Merkies, Ingemar S. J.; Thonnard, Jean-L.; Barreira, A. A.; Bennett, D.; Hadden, R. D.; Hughes, R. A. C.; Lunn, M. P. T.; Reilly, M. M.; van den Berg, L. H.; van Doorn, P. A.; Faber, C. G.; van der Kooi, A. J.; Merkies, I. S. J.; Notermans, N. C.; Raaphorts, J.; van Schaik, I. N.; de Visser, M.; Cats, E. A.; van den Bergh, P. Y. K.; Bombelli, F.; Costa, R.; Franques, J.; Léger, J.-M.; Pouget, J.; Bril, V.; Hahn, A. F.; Katzberg, H.; Campanella, A.; Devigili, G.; Gallia, F.; Lauria, G.; Nobile-Orazio, E.; Padua, L.; Cornblath, D. R.; Gorson, K. C.; Lewis, R. A.; Illa, I.; Querol, L.; van Nes, S. I.

    2015-01-01

    Outcome measures are considered the most important tools to monitor patients' outcome in both clinical and research settings. Measuring the clinical state of patients is a fundamental part of our daily clinical practice and research that sometimes is taken for granted. In peripheral neuropathies,

  4. 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.

  5. 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

  6. 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…

  7. A measure of early physical functioning (EPF) post-stroke.

    Science.gov (United States)

    Finch, Lois E; Higgins, Johanne; Wood-Dauphinee, Sharon; Mayo, Nancy E

    2008-07-01

    To develop a comprehensive measure of Early Physical Functioning (EPF) post-stroke quantified through Rasch analysis and conceptualized using the International Classification of Functioning Disability and Health (ICF). An observational cohort study. A cohort of 262 subjects (mean age 71.6 (standard deviation 12.5) years) hospitalized post-acute stroke. Functional assessments were made within 3 days of stroke with items from valid and reliable indices commonly utilized to evaluate stroke survivors. Information on important variables was also collected. Principal component and Rasch analysis confirmed the factor structure, and dimensionality of the measure. Rasch analysis combined items across ICF components to develop the measure. Items were deleted iteratively, those retained fit the model and were related to the construct; reliability and validity were assessed. A 38-item unidimensional measure of the EPF met all Rasch model requirements. The item difficulty matched the person ability (mean person measure: -0.31; standard error 0.37 logits), reliability of the person-item-hierarchy was excellent at 0.97. Initial validity was adequate. The 38-item EPF measure was developed. It expands the range of assessment post acute stroke; it covers a broad spectrum of difficulty with good initial psychometric properties that, once revalidated, can assist in planning and evaluating early interventions.

  8. 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

    The Revised Danish Learning Styles Inventory (R-D-LSI) (Nielsen 2005), which is an adaptation of Sternberg- Wagner Thinking Styles Inventory (Sternberg, 1997), comprises 14 subscales, each measuring a separate learning style. Of these 14 subscales, 9 are eight items long and 5 are seven items long...... Inventory (D-SA-LSI) comprising 14 subscales each with an item length of seven. The systematic approach to item reduction based on results of GLLRM will be presented and exemplified by its application to the R-D-LSI....

  9. Investigating the Measurement Properties of the Social Responsiveness Scale in Preschool Children with Autism Spectrum Disorders

    Science.gov (United States)

    Duku, Eric; Vaillancourt, Tracy; Szatmari, Peter; Georgiades, Stelios; Zwaigenbaum, Lonnie; Smith, Isabel M.; Bryson, Susan; Fombonne, Eric; Mirenda, Pat; Roberts, Wendy; Volden, Joanne; Waddell, Charlotte; Thompson, Ann; Bennett, Teresa

    2013-01-01

    The purpose of this study was to examine the measurement properties of the Social Responsiveness Scale in an accelerated longitudinal sample of 4-year-old preschool children with the complementary approaches of categorical confirmatory factor analysis and Rasch analysis. Measurement models based on the literature and other hypothesized measurement…

  10. 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 Interview fails to fully operationalize a quantitative conceptualization of caregiver burden among caregivers to patients with 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.

  11. Measuring and modelling concurrency

    Science.gov (United States)

    Sawers, Larry

    2013-01-01

    This article explores three critical topics discussed in the recent debate over concurrency (overlapping sexual partnerships): measurement of the prevalence of concurrency, mathematical modelling of concurrency and HIV epidemic dynamics, and measuring the correlation between HIV and concurrency. The focus of the article is the concurrency hypothesis – the proposition that presumed high prevalence of concurrency explains sub-Saharan Africa's exceptionally high HIV prevalence. Recent surveys using improved questionnaire design show reported concurrency ranging from 0.8% to 7.6% in the region. Even after adjusting for plausible levels of reporting errors, appropriately parameterized sexual network models of HIV epidemics do not generate sustainable epidemic trajectories (avoid epidemic extinction) at levels of concurrency found in recent surveys in sub-Saharan Africa. Efforts to support the concurrency hypothesis with a statistical correlation between HIV incidence and concurrency prevalence are not yet successful. Two decades of efforts to find evidence in support of the concurrency hypothesis have failed to build a convincing case. PMID:23406964

  12. The Reliability and Validity of the Power-Load-Margin Inventory: A Rasch Analysis.

    Science.gov (United States)

    Hardigan, Patrick C; Cohen, Stanley R; Hagen, Kathleen P

    2015-01-01

    Margin is a function of the relationship of stress to strength. The greater the margin, the more likely students are able to successfully navigate academic structures. This study examined the psychometric properties of a newly created instrument designed to measure margin - the Power-Load-Margin Inventory (PLMI). The PLMI was created using eight domains: (A) Student's aptitude and ability, (B) Course structure, (C) External motivation, (D) Student health, (E) Instructor style, (F) Internal motivation, (G) Life opportunities, and (H) University support structure. A three-point response scale was used to measure the domains: (1) stress, (2) neither stress nor strength, and (3) strength. The PLMI was administered to 586 medical, dental, and pharmacy students. A Rasch rating scale model was used to examine the psychometric properties of the PLMI. The PLMI demonstrated acceptable psychometric properties for use with pharmacy, dental, and medical students. The PLMI's primary weakness was with the subscales' reliability. We attribute this to the small number of items per subscale.

  13. 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.

  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. On measurements and models

    International Nuclear Information System (INIS)

    McDonald, J. C.

    2012-01-01

    The 2011 Nobel Prize for physics was awarded to three astronomers for their measurements that were interpreted as providing evidence of an acceleration in the expansion of the universe rather than a slowing, as had been expected. The subsequent theoretical explanation, or model, of the observed phenomenon led to the postulation of 'dark matter' or 'dark energy'. The implications of this new form of energy are startling to say the least. The following quote came from an article about the Nobel Prize award in the New York Times. If the universe continues accelerating, astronomers say, rather than coasting gently into the night, distant galaxies will eventually be moving apart so quickly that they cannot communicate with one another and all the energy will be sucked out of the universe. (author)

  16. 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...

  17. 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,…

  18. Predicting the need for institutional care shortly after admission to rehabilitation: Rasch analysis and predictive validity of the BRASS Index.

    Science.gov (United States)

    Panella, L; La Porta, F; Caselli, S; Marchisio, S; Tennant, A

    2012-09-01

    Effective discharge planning is increasingly recognised as a critical component of hospital-based Rehabilitation. The BRASS index is a risk screening tool for identification, shortly after hospital admission, of patients who are at risk of post-discharge problems. To evaluate the internal construct validity and reliability of the Blaylock Risk Assessment Screening Score (BRASS) within the rehabilitation setting. Observational prospective study. Rehabilitation ward of an Italian district hospital. One hundred and four consecutively admitted patients. Using classical psychometric methods and Rasch analysis (RA), the internal construct validity and reliability of the BRASS were examined. Also, external and predictive validity of the Rasch-modified BRASS (RMB) score were determined. Reliability of the original BRASS was low (Cronbach's alpha=0.595) and factor analyses showed that it was clearly multidimensional. A RA, based on a reduced 7-BRASS item set (RMB), satisfied model's expectations. Reliability was 0.777. The RMB scores strongly correlated with the original BRASS (rho=0.952; P28 days (RR=7.6, 95%CI=1.8-31.9). This study demonstrated that the original BRASS was multidimensional and unreliable. However, the RMB holds adequate internal construct validity and is sufficiently reliable as a predictor of discharge problems for group, but not individual use. The application of tools and methods (such as the BRASS Index) developed under the biomedical paradigm in a Physical and Rehabilitation Medicine setting may have limitations. Further research is needed to develop, within the rehabilitation setting, a valid measuring tool of risk of post-discharge problems at the individual level.

  19. A Model of Trusted Measurement Model

    OpenAIRE

    Ma Zhili; Wang Zhihao; Dai Liang; Zhu Xiaoqin

    2017-01-01

    A model of Trusted Measurement supporting behavior measurement based on trusted connection architecture (TCA) with three entities and three levels is proposed, and a frame to illustrate the model is given. The model synthesizes three trusted measurement dimensions including trusted identity, trusted status and trusted behavior, satisfies the essential requirements of trusted measurement, and unified the TCA with three entities and three levels.

  20. Applying computerized adaptive testing to the Negative Acts Questionnaire-Revised: Rasch analysis of workplace bullying.

    Science.gov (United States)

    Ma, Shu-Ching; Chien, Tsair-Wei; Wang, Hsiu-Hung; Li, Yu-Chi; Yui, Mei-Shu

    2014-02-17

    Workplace bullying is a prevalent problem in contemporary work places that has adverse effects on both the victims of bullying and organizations. With the rapid development of computer technology in recent years, there is an urgent need to prove whether item response theory-based computerized adaptive testing (CAT) can be applied to measure exposure to workplace bullying. The purpose of this study was to evaluate the relative efficiency and measurement precision of a CAT-based test for hospital nurses compared to traditional nonadaptive testing (NAT). Under the preliminary conditions of a single domain derived from the scale, a CAT module bullying scale model with polytomously scored items is provided as an example for evaluation purposes. A total of 300 nurses were recruited and responded to the 22-item Negative Acts Questionnaire-Revised (NAQ-R). All NAT (or CAT-selected) items were calibrated with the Rasch rating scale model and all respondents were randomly selected for a comparison of the advantages of CAT and NAT in efficiency and precision by paired t tests and the area under the receiver operating characteristic curve (AUROC). The NAQ-R is a unidimensional construct that can be applied to measure exposure to workplace bullying through CAT-based administration. Nursing measures derived from both tests (CAT and NAT) were highly correlated (r=.97) and their measurement precisions were not statistically different (P=.49) as expected. CAT required fewer items than NAT (an efficiency gain of 32%), suggesting a reduced burden for respondents. There were significant differences in work tenure between the 2 groups (bullied and nonbullied) at a cutoff point of 6 years at 1 worksite. An AUROC of 0.75 (95% CI 0.68-0.79) with logits greater than -4.2 (or >30 in summation) was defined as being highly likely bullied in a workplace. With CAT-based administration of the NAQ-R for nurses, their burden was substantially reduced without compromising measurement precision.

  1. 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.

  2. Examining Measurement Properties of an English Self-Efficacy Scale for English Language Learners in Korea

    Science.gov (United States)

    Wang, Chuang; Kim, Do-Hong; Bong, Mimi; Ahn, Hyun Seon

    2013-01-01

    This study provides evidence for the validity of the Questionnaire of English Self-Efficacy in a sample of 167 college students in Korea. Results show that the scale measures largely satisfy the Rasch model for unidimensionality. The rating scale appeared to function effectively. The item hierarchy was consistent with the expected item order. The…

  3. Measuring Change in Academic Self-Concept Resulting from Curricular and Instructional Innovations

    Science.gov (United States)

    Anderson, Lorin W.

    1977-01-01

    The Rasch Model was applied to the results of an academic self-concept test administered to junior high school students, and some items were eliminated. The resulting scale possessed several properties permitting its use in the measurement of school-induced change in self-concept. The questionnaire is appended. (Author/MV)

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

    Directory of Open Access Journals (Sweden)

    Velikova Galina

    2010-04-01

    Full Text Available Abstract 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.

  5. 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.

  6. Environmental Measurements and Modeling

    Science.gov (United States)

    Environmental measurement is any data collection activity involving the assessment of chemical, physical, or biological factors in the environment which affect human health. Learn more about these programs and tools that aid in environmental decisions

  7. Separating models, ideas, and data to avoid a paradox : Rejoinder to Humphry

    NARCIS (Netherlands)

    Sijtsma, K.; Emons, W.H.M.

    2013-01-01

    This article is a rejoinder to Humphry’s (2013) comment on Sijtsma (2012). Sijtsma argued that the Rasch paradox does not exist but Humphry replies that the Rasch paradox can occur provided the measurement procedure is precise enough. The rejoinder argues that the debates about the Rasch paradox

  8. Rasch analysis of the Multiple Sclerosis Impact Scale (MSIS-29

    Directory of Open Access Journals (Sweden)

    Misajon Rose

    2009-06-01

    Full Text Available Abstract Background Multiple Sclerosis (MS is a degenerative neurological disease that causes impairments, including spasticity, pain, fatigue, and bladder dysfunction, which negatively impact on quality of life. The Multiple Sclerosis Impact Scale (MSIS-29 is a disease-specific health-related quality of life (HRQoL instrument, developed using the patient's perspective on disease impact. It consists of two subscales assessing the physical (MSIS-29-PHYS and psychological (MSIS-29-PSYCH impact of MS. Although previous studies have found support for the psychometric properties of the MSIS-29 using traditional methods of scale evaluation, the scale has not been subjected to a detailed Rasch analysis. Therefore, the objective of this study was to use Rasch analysis to assess the internal validity of the scale, and its response format, item fit, targeting, internal consistency and dimensionality. Methods Ninety-two persons with definite MS residing in the community were recruited from a tertiary hospital database. Patients completed the MSIS-29 as part of a larger study. Rasch analysis was undertaken to assess the psychometric properties of the MSIS-29. Results Rasch analysis showed overall support for the psychometric properties of the two MSIS-29 subscales, however it was necessary to reduce the response format of the MSIS-29-PHYS to a 3-point response scale. Both subscales were unidimensional, had good internal consistency, and were free from item bias for sex and age. Dimensionality testing indicated it was not appropriate to combine the two subscales to form a total MSIS score. Conclusion In this first study to use Rasch analysis to fully assess the psychometric properties of the MSIS-29 support was found for the two subscales but not for the use of the total scale. Further use of Rasch analysis on the MSIS-29 in larger and broader samples is recommended to confirm these findings.

  9. Rasch analysis of the Multiple Sclerosis Impact Scale (MSIS-29)

    Science.gov (United States)

    Ramp, Melina; Khan, Fary; Misajon, Rose Anne; Pallant, Julie F

    2009-01-01

    Background Multiple Sclerosis (MS) is a degenerative neurological disease that causes impairments, including spasticity, pain, fatigue, and bladder dysfunction, which negatively impact on quality of life. The Multiple Sclerosis Impact Scale (MSIS-29) is a disease-specific health-related quality of life (HRQoL) instrument, developed using the patient's perspective on disease impact. It consists of two subscales assessing the physical (MSIS-29-PHYS) and psychological (MSIS-29-PSYCH) impact of MS. Although previous studies have found support for the psychometric properties of the MSIS-29 using traditional methods of scale evaluation, the scale has not been subjected to a detailed Rasch analysis. Therefore, the objective of this study was to use Rasch analysis to assess the internal validity of the scale, and its response format, item fit, targeting, internal consistency and dimensionality. Methods Ninety-two persons with definite MS residing in the community were recruited from a tertiary hospital database. Patients completed the MSIS-29 as part of a larger study. Rasch analysis was undertaken to assess the psychometric properties of the MSIS-29. Results Rasch analysis showed overall support for the psychometric properties of the two MSIS-29 subscales, however it was necessary to reduce the response format of the MSIS-29-PHYS to a 3-point response scale. Both subscales were unidimensional, had good internal consistency, and were free from item bias for sex and age. Dimensionality testing indicated it was not appropriate to combine the two subscales to form a total MSIS score. Conclusion In this first study to use Rasch analysis to fully assess the psychometric properties of the MSIS-29 support was found for the two subscales but not for the use of the total scale. Further use of Rasch analysis on the MSIS-29 in larger and broader samples is recommended to confirm these findings. PMID:19545445

  10. Model plant Key Measurement Points

    International Nuclear Information System (INIS)

    Schneider, R.A.

    1984-01-01

    For IAEA safeguards a Key Measurement Point is defined as the location where nuclear material appears in such a form that it may be measured to determine material flow or inventory. This presentation describes in an introductory manner the key measurement points and associated measurements for the model plant used in this training course

  11. Factor and Rasch analysis of the Fonseca anamnestic index for the diagnosis of myogenous temporomandibular disorder.

    Science.gov (United States)

    Rodrigues-Bigaton, Delaine; de Castro, Ester M; Pires, Paulo F

    Rasch analysis has been used in recent studies to test the psychometric properties of a questionnaire. The conditions for use of the Rasch model are one-dimensionality (assessed via prior factor analysis) and local independence (the probability of getting a particular item right or wrong should not be conditioned upon success or failure in another). To evaluate the dimensionality and the psychometric properties of the Fonseca anamnestic index (FAI), such as the fit of the data to the model, the degree of difficulty of the items, and the ability to respond in patients with myogenous temporomandibular disorder (TMD). The sample consisted of 94 women with myogenous TMD, diagnosed by the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), who answered the FAI. For the factor analysis, we applied the Kaiser-Meyer-Olkin test, Bartlett's sphericity, Spearman's correlation, and the determinant of the correlation matrix. For extraction of the factors/dimensions, an eigenvalue >1.0 was used, followed by oblique oblimin rotation. The Rasch analysis was conducted on the dimension that showed the highest proportion of variance explained. Adequate sample "n" and FAI multidimensionality were observed. Dimension 1 (primary) consisted of items 1, 2, 3, 6, and 7. All items of dimension 1 showed adequate fit to the model, being observed according to the degree of difficulty (from most difficult to easiest), respectively, items 2, 1, 3, 6, and 7. The FAI presented multidimensionality with its main dimension consisting of five reliable items with adequate fit to the composition of its structure. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  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. A comparison of Rasch item-fit and Cronbach's alpha item reduction analysis for the development of a Quality of Life scale for children and adolescents.

    Science.gov (United States)

    Erhart, M; Hagquist, C; Auquier, P; Rajmil, L; Power, M; Ravens-Sieberer, U

    2010-07-01

    This study compares item reduction analysis based on classical test theory (maximizing Cronbach's alpha - approach A), with analysis based on the Rasch Partial Credit Model item-fit (approach B), as applied to children and adolescents' health-related quality of life (HRQoL) items. The reliability and structural, cross-cultural and known-group validity of the measures were examined. Within the European KIDSCREEN project, 3019 children and adolescents (8-18 years) from seven European countries answered 19 HRQoL items of the Physical Well-being dimension of a preliminary KIDSCREEN instrument. The Cronbach's alpha and corrected item total correlation (approach A) were compared with infit mean squares and the Q-index item-fit derived according to a partial credit model (approach B). Cross-cultural differential item functioning (DIF ordinal logistic regression approach), structural validity (confirmatory factor analysis and residual correlation) and relative validity (RV) for socio-demographic and health-related factors were calculated for approaches (A) and (B). Approach (A) led to the retention of 13 items, compared with 11 items with approach (B). The item overlap was 69% for (A) and 78% for (B). The correlation coefficient of the summated ratings was 0.93. The Cronbach's alpha was similar for both versions [0.86 (A); 0.85 (B)]. Both approaches selected some items that are not strictly unidimensional and items displaying DIF. RV ratios favoured (A) with regard to socio-demographic aspects. Approach (B) was superior in RV with regard to health-related aspects. Both types of item reduction analysis should be accompanied by additional analyses. Neither of the two approaches was universally superior with regard to cultural, structural and known-group validity. However, the results support the usability of the Rasch method for developing new HRQoL measures for children and adolescents.

  14. Improving the Individual Work Performance Questionnaire using Rasch analysis.

    NARCIS (Netherlands)

    Koopmans, L.; Bernaards, C.M.; Hildebrandt, V.H.; Buuren, S. van; Beek, A.J. van der; Vet, H.C.W. de

    2014-01-01

    Recently, the Individual Work Performance Questionnaire (IWPQ) version 0.2 was developed using Rasch analysis. The goal of the current study was to improve targeting of the IWPQ scales by including additional items. The IWPQ 0.2 (original) and 0.3 (including additional items) were examined using

  15. 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...

  16. Local Equating Using the Rasch Model, the OPLM, and the 2PL IRT Model--or--What Is It Anyway if the Model Captures Everything There Is to Know about the Test Takers?

    Science.gov (United States)

    von Davier, Matthias; González B., Jorge; von Davier, Alina A.

    2013-01-01

    Local equating (LE) is based on Lord's criterion of equity. It defines a family of true transformations that aim at the ideal of equitable equating. van der Linden (this issue) offers a detailed discussion of common issues in observed-score equating relative to this local approach. By assuming an underlying item response theory model, one of…

  17. Rasch validation of the Chinese parent-child interaction scale (CPCIS).

    Science.gov (United States)

    Ip, Patrick; Tso, Winnie; Rao, Nirmala; Ho, Frederick Ka Wing; Chan, Ko Ling; Fu, King Wa; Li, Sophia Ling; Goh, Winnie; Wong, Wilfred Hing-Sang; Chow, Chun Bong

    2018-03-15

    Proper parent-child interaction is crucial for child development, but an assessment tool in Chinese is currently lacking. This study aimed to develop and validate a parent-reported parent-child interaction scale for Chinese preschool children. The Chinese parent-child interaction scale (CPCIS) was designed by an expert panel based on the literature and clinical observations in the Chinese context. The initial CPCIS had 14 parent-child interactive activity items. Psychometric properties of the CPCIS were examined using the Rasch model and confirmatory factor analysis (CFA). Convergent validity was investigated by the associations between CPCIS and family income, maternal education level, and children's school readiness. The study recruited 567 Chinese parent-child pairs from diverse socioeconomic backgrounds, who completed the CPCIS. Six out of the 14 items in the initial CPCIS were dropped due to suboptimal fit values. The refined 8-item CPCIS was shown to be valid and reliable by Rasch models and CFA. The person separation reliability and Cronbach's α of the CPCIS were 0.81 and 0.82, respectively. The CPCIS scores were positively associated with family's socioeconomic status (η 2  = 0.05, P parent-child interactions in Chinese families.

  18. A longitudinal evaluation of the Center for Epidemiologic Studies-Depression scale (CES-D) in a Rheumatoid Arthritis Population using Rasch Analysis

    Science.gov (United States)

    Covic, Tanya; Pallant, Julie F; Conaghan, Philip G; Tennant, Alan

    2007-01-01

    Background The aim of this study was to test the internal validity of the total Center for Epidemiologic Studies-Depression (CES-D) scale using Rasch analysis in a rheumatoid arthritis (RA) population. Methods CES-D was administered to 157 patients with RA over three time points within a 12 month period. Rasch analysis was applied using RUMM2020 software to assess the overall fit of the model, the response scale used, individual item fit, differential item functioning (DIF) and person separation. Results Pooled data across three time points was shown to fit the Rasch model with removal of seven items from the original 20-item CES-D scale. It was necessary to rescore the response format from four to three categories in order to improve the scale's fit. Two items demonstrated some DIF for age and gender but were retained within the 13-item CES-D scale. A new cut point for depression score of 9 was found to correspond to the original cut point score of 16 in the full CES-D scale. Conclusion This Rasch analysis of the CES-D in a longstanding RA cohort resulted in the construction of a modified 13-item scale with good internal validity. Further validation of the modified scale is recommended particularly in relation to the new cut point for depression. PMID:17629902

  19. A longitudinal evaluation of the Center for Epidemiologic Studies-Depression scale (CES-D in a Rheumatoid Arthritis Population using Rasch Analysis

    Directory of Open Access Journals (Sweden)

    Tennant Alan

    2007-07-01

    Full Text Available Abstract Background The aim of this study was to test the internal validity of the total Center for Epidemiologic Studies-Depression (CES-D scale using Rasch analysis in a rheumatoid arthritis (RA population. Methods CES-D was administered to 157 patients with RA over three time points within a 12 month period. Rasch analysis was applied using RUMM2020 software to assess the overall fit of the model, the response scale used, individual item fit, differential item functioning (DIF and person separation. Results Pooled data across three time points was shown to fit the Rasch model with removal of seven items from the original 20-item CES-D scale. It was necessary to rescore the response format from four to three categories in order to improve the scale's fit. Two items demonstrated some DIF for age and gender but were retained within the 13-item CES-D scale. A new cut point for depression score of 9 was found to correspond to the original cut point score of 16 in the full CES-D scale. Conclusion This Rasch analysis of the CES-D in a longstanding RA cohort resulted in the construction of a modified 13-item scale with good internal validity. Further validation of the modified scale is recommended particularly in relation to the new cut point for depression.

  20. Assessing Validity of Measurement in Learning Disabilities Using Hierarchical Generalized Linear Modeling: The Roles of Anxiety and Motivation

    Science.gov (United States)

    Sideridis, Georgios D.

    2016-01-01

    The purpose of the present studies was to test the hypothesis that the psychometric characteristics of ability scales may be significantly distorted if one accounts for emotional factors during test taking. Specifically, the present studies evaluate the effects of anxiety and motivation on the item difficulties of the Rasch model. In Study 1, the…

  1. A Comparison of the One-and Three-Parameter Logistic Models on Measures of Test Efficiency.

    Science.gov (United States)

    Benson, Jeri

    Two methods of item selection were used to select sets of 40 items from a 50-item verbal analogies test, and the resulting item sets were compared for relative efficiency. The BICAL program was used to select the 40 items having the best mean square fit to the one parameter logistic (Rasch) model. The LOGIST program was used to select the 40 items…

  2. 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).

  3. The ProQOL-21: A revised version of the Professional Quality of Life (ProQOL) scale based on Rasch analysis

    Science.gov (United States)

    Rees, Clare S.; Hegney, Desley G.

    2018-01-01

    The Professional Quality of Life scale is a measure intended to provide practitioners and researchers with an indication of a caring professional’s compassion satisfaction, burnout, and secondary traumatic stress. While this measure has been used extensively in nursing research, owing to the relevancy of patient-care associated satisfaction and fatigue within this profession, information regarding the construct validity of this measure is less well represented in the literature. We examined the construct validity of the Professional Quality of Life scale using a Rasch analysis procedure on each of its three scales, as a means of substantiating their measurement adequacy. Responses on the Professional Quality of Life scale from 1615 registered nurses (age x̅ = 46.48 years, SD = 11.78) were analysed. While support for the measurement adequacy (invariance, person/item fit, and unidimensionality) of the compassion satisfaction scale was found, the burnout and secondary traumatic stress scales did not demonstrate adequate measurement properties. We instead present an alternative measurement model of these subscales, involving items from each, to form a robust measure of compassion fatigue, and provide recoding, scoring, and normed scores for both measures. Our findings indicate that use of the Professional Quality of Life scale’s burnout and secondary traumatic stress scales may require caution, while our revised compassion satisfaction and fatigue scales provide robust measurement options for practitioners and researchers. PMID:29489875

  4. The ProQOL-21: A revised version of the Professional Quality of Life (ProQOL scale based on Rasch analysis.

    Directory of Open Access Journals (Sweden)

    Brody Heritage

    Full Text Available The Professional Quality of Life scale is a measure intended to provide practitioners and researchers with an indication of a caring professional's compassion satisfaction, burnout, and secondary traumatic stress. While this measure has been used extensively in nursing research, owing to the relevancy of patient-care associated satisfaction and fatigue within this profession, information regarding the construct validity of this measure is less well represented in the literature. We examined the construct validity of the Professional Quality of Life scale using a Rasch analysis procedure on each of its three scales, as a means of substantiating their measurement adequacy. Responses on the Professional Quality of Life scale from 1615 registered nurses (age x̅ = 46.48 years, SD = 11.78 were analysed. While support for the measurement adequacy (invariance, person/item fit, and unidimensionality of the compassion satisfaction scale was found, the burnout and secondary traumatic stress scales did not demonstrate adequate measurement properties. We instead present an alternative measurement model of these subscales, involving items from each, to form a robust measure of compassion fatigue, and provide recoding, scoring, and normed scores for both measures. Our findings indicate that use of the Professional Quality of Life scale's burnout and secondary traumatic stress scales may require caution, while our revised compassion satisfaction and fatigue scales provide robust measurement options for practitioners and researchers.

  5. Models of Credit Risk Measurement

    OpenAIRE

    Hagiu Alina

    2011-01-01

    Credit risk is defined as that risk of financial loss caused by failure by the counterparty. According to statistics, for financial institutions, credit risk is much important than market risk, reduced diversification of the credit risk is the main cause of bank failures. Just recently, the banking industry began to measure credit risk in the context of a portfolio along with the development of risk management started with models value at risk (VAR). Once measured, credit risk can be diversif...

  6. Internet advertising effectiveness measurement model

    OpenAIRE

    Marcinkevičiūtė, Milda

    2007-01-01

    The research object of the master thesis is internet advertising effectiveness measurement. The goal of the work is after making theoretical studies of internet advertising effectiveness measurement (theoretical articles, practical researches and cetera), formulate the conceptual IAEM model and examine it empirically. The main tasks of the work are: to analyze internet advertising, it’s features, purposes, spread formats, functions, advantages and disadvantages; present the effectiveness of i...

  7. 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.

  8. Division Quilts: A Measurement Model

    Science.gov (United States)

    Pratt, Sarah S.; Lupton, Tina M.; Richardson, Kerri

    2015-01-01

    As teachers seek activities to assist students in understanding division as more than just the algorithm, they find many examples of division as fair sharing. However, teachers have few activities to engage students in a quotative (measurement) model of division. Efraim Fischbein and his colleagues (1985) defined two types of whole-number…

  9. The integration of bioclimatic indices in an objective probabilistic model for establishing and mapping viticulture suitability in a region

    Science.gov (United States)

    Moral García, Francisco J.; Rebollo, Francisco J.; Paniagua, Luis L.; García, Abelardo

    2014-05-01

    Different bioclimatic indices have been proposed to determine the wine suitability in a region. Some of them are related to the air temperature, but the hydric component of climate should also be considered which, in turn, is influenced by the precipitation during the different stages of the grapevine growing and ripening periods. In this work we propose using the information obtained from 10 bioclimatic indices and variables (heliothermal index, HI, cool night index, CI, dryness index, DI, growing season temperature, GST, the Winkler index, WI, September mean thermal amplitude, MTA, annual precipitation, AP, precipitation during flowering, PDF, precipitation before flowering, PBF, and summer precipitation, SP) as inputs in an objective and probabilistic model, the Rasch model, with the aim of integrating the individual effects of them, obtaining the climate data that summarize all main bioclimatic indices which could influence on wine suitability, and utilize the Rasch measures to generate homogeneous climatic zones. The use of the Rasch model to estimate viticultural suitability constitutes a new application of great practical importance, enabling to rationally determine locations in a region where high viticultural potential exists and establishing a ranking of the bioclimatic indices or variables which exerts an important influence on wine suitability in a region. Furthermore, from the measures of viticultural suitability at some locations, estimates can be computed using a geostatistical algorithm, and these estimates can be utilized to map viticultural suitability potential in a region. To illustrate the process, an application to Extremadura, southewestern Spain, is shown. Keywords: Rasch model, bioclimatic indices, GIS.

  10. Factors associated with knowledge of diabetes in patients with type 2 diabetes using the Diabetes Knowledge Test validated with Rasch analysis.

    Directory of Open Access Journals (Sweden)

    Eva K Fenwick

    Full Text Available OBJECTIVE: In patients with Type 2 diabetes, to determine the factors associated with diabetes knowledge, derived from Rasch analysis, and compare results with a traditional raw scoring method. RESEARCH DESIGN & METHODS: Participants in this cross-sectional study underwent a comprehensive clinical and biochemical assessment. Diabetes knowledge (main outcome was assessed using the Diabetes Knowledge Test (DKT which was psychometrically validated using Rasch analysis. The relationship between diabetes knowledge and risk factors identified during univariate analyses was examined using multivariable linear regression. The results using raw and Rasch-transformed methods were descriptively compared. RESULTS: 181 patients (mean age±standard deviation = 66.97±9.17 years; 113 (62% male were included. Using Rasch-derived DKT scores, those with greater education (β = 1.14; CI: 0.25,2.04, p = 0.013; had seen an ophthalmologist (β = 1.65; CI: 0.63,2.66, p = 0.002, and spoke English at home (β = 1.37; CI: 0.43,2.31, p = 0.005 had significantly better diabetes knowledge than those with less education, had not seen an ophthalmologist and spoke a language other than English, respectively. Patients who were members of the National Diabetes Service Scheme (NDSS and had seen a diabetes educator also had better diabetes knowledge than their counterparts. Higher HbA1c level was independently associated with worse diabetes knowledge. Using raw measures, access to an ophthalmologist and NDSS membership were not independently associated with diabetes knowledge. CONCLUSIONS: Sociodemographic, clinical and service use factors were independently associated with diabetes knowledge based on both raw scores and Rasch-derived scores, which supports the implementation of targeted interventions to improve patients' knowledge. Choice of psychometric analytical method can affect study outcomes and should be considered during intervention

  11. Factors Associated with Knowledge of Diabetes in Patients with Type 2 Diabetes Using the Diabetes Knowledge Test Validated with Rasch Analysis

    Science.gov (United States)

    Fenwick, Eva K.; Xie, Jing; Rees, Gwyn; Finger, Robert P.; Lamoureux, Ecosse L.

    2013-01-01

    Objective In patients with Type 2 diabetes, to determine the factors associated with diabetes knowledge, derived from Rasch analysis, and compare results with a traditional raw scoring method. Research Design & Methods Participants in this cross-sectional study underwent a comprehensive clinical and biochemical assessment. Diabetes knowledge (main outcome) was assessed using the Diabetes Knowledge Test (DKT) which was psychometrically validated using Rasch analysis. The relationship between diabetes knowledge and risk factors identified during univariate analyses was examined using multivariable linear regression. The results using raw and Rasch-transformed methods were descriptively compared. Results 181 patients (mean age±standard deviation = 66.97±9.17 years; 113 (62%) male) were included. Using Rasch-derived DKT scores, those with greater education (β = 1.14; CI: 0.25,2.04, p = 0.013); had seen an ophthalmologist (β = 1.65; CI: 0.63,2.66, p = 0.002), and spoke English at home (β = 1.37; CI: 0.43,2.31, p = 0.005) had significantly better diabetes knowledge than those with less education, had not seen an ophthalmologist and spoke a language other than English, respectively. Patients who were members of the National Diabetes Service Scheme (NDSS) and had seen a diabetes educator also had better diabetes knowledge than their counterparts. Higher HbA1c level was independently associated with worse diabetes knowledge. Using raw measures, access to an ophthalmologist and NDSS membership were not independently associated with diabetes knowledge. Conclusions Sociodemographic, clinical and service use factors were independently associated with diabetes knowledge based on both raw scores and Rasch-derived scores, which supports the implementation of targeted interventions to improve patients' knowledge. Choice of psychometric analytical method can affect study outcomes and should be considered during intervention development. PMID:24312484

  12. Linear Logistic Test Modeling with R

    Science.gov (United States)

    Baghaei, Purya; Kubinger, Klaus D.

    2015-01-01

    The present paper gives a general introduction to the linear logistic test model (Fischer, 1973), an extension of the Rasch model with linear constraints on item parameters, along with eRm (an R package to estimate different types of Rasch models; Mair, Hatzinger, & Mair, 2014) functions to estimate the model and interpret its parameters. The…

  13. 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

    2016-01-01

    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…

  14. Examination of a Social-Networking Site Activities Scale (SNSAS) Using Rasch Analysis

    Science.gov (United States)

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

    2017-01-01

    This study examined the psychometric properties of a social-networking site (SNS) activities scale (SNSAS) 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 the United States [US] and Europe; N =…

  15. Solar Measurement and Modeling | Grid Modernization | NREL

    Science.gov (United States)

    Measurement and Modeling Solar Measurement and Modeling NREL supports grid integration studies , industry, government, and academia by disseminating solar resource measurements, models, and best practices have continuously gathered basic solar radiation information, and they now gather high-resolution data

  16. 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.

  17. Measurement error models with interactions

    Science.gov (United States)

    Midthune, Douglas; Carroll, Raymond J.; Freedman, Laurence S.; Kipnis, Victor

    2016-01-01

    An important use of measurement error models is to correct regression models for bias due to covariate measurement error. Most measurement error models assume that the observed error-prone covariate (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$W$\\end{document}) is a linear function of the unobserved true covariate (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$X$\\end{document}) plus other covariates (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$Z$\\end{document}) in the regression model. In this paper, we consider models for \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$W$\\end{document} that include interactions between \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$X$\\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$Z$\\end{document}. We derive the conditional distribution of

  18. Physics Metacognition Inventory Part II: Confirmatory factor analysis and Rasch analysis

    Science.gov (United States)

    Taasoobshirazi, Gita; Bailey, MarLynn; Farley, John

    2015-11-01

    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, planning, monitoring, evaluation, debugging, and information management. The college students' scores on the inventory were found to be reliable and related to students' physics motivation and physics grade. However, the results of the exploratory factor analysis indicated that the questionnaire could be revised to improve its construct validity. The goal of this study was to revise the questionnaire and establish its construct validity through a confirmatory factor analysis. In addition, a Rasch analysis was applied to the data to better understand the psychometric properties of the inventory and to further evaluate the construct validity. Results indicated that the final, revised inventory is a valid, reliable, and efficient tool for assessing student metacognition for physics problem solving.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Aerial Measuring System Sensor Modeling

    International Nuclear Information System (INIS)

    Detwiler, R.S.

    2002-01-01

    This project deals with the modeling the Aerial Measuring System (AMS) fixed-wing and rotary-wing sensor systems, which are critical U.S. Department of Energy's National Nuclear Security Administration (NNSA) Consequence Management assets. The fixed-wing system is critical in detecting lost or stolen radiography or medical sources, or mixed fission products as from a commercial power plant release at high flying altitudes. The helicopter is typically used at lower altitudes to determine ground contamination, such as in measuring americium from a plutonium ground dispersal during a cleanup. Since the sensitivity of these instruments as a function of altitude is crucial in estimating detection limits of various ground contaminations and necessary count times, a characterization of their sensitivity as a function of altitude and energy is needed. Experimental data at altitude as well as laboratory benchmarks is important to insure that the strong effects of air attenuation are modeled correctly. The modeling presented here is the first attempt at such a characterization of the equipment for flying altitudes. The sodium iodide (NaI) sensors utilized with these systems were characterized using the Monte Carlo N-Particle code (MCNP) developed at Los Alamos National Laboratory. For the fixed wing system, calculations modeled the spectral response for the 3-element NaI detector pod and High-Purity Germanium (HPGe) detector, in the relevant energy range of 50 keV to 3 MeV. NaI detector responses were simulated for both point and distributed surface sources as a function of gamma energy and flying altitude. For point sources, photopeak efficiencies were calculated for a zero radial distance and an offset equal to the altitude. For distributed sources approximating an infinite plane, gross count efficiencies were calculated and normalized to a uniform surface deposition of 1 microCi/m 2 . The helicopter calculations modeled the transport of americium-241 ( 241 Am) as this is

  1. Conceptualising computerized adaptive testing for measurement of latent variables associated with physical objects

    International Nuclear Information System (INIS)

    Camargo, F R; Henson, B

    2015-01-01

    The notion of that more or less of a physical feature affects in different degrees the users' impression with regard to an underlying attribute of a product has frequently been applied in affective engineering. However, those attributes exist only as a premise that cannot directly be measured and, therefore, inferences based on their assessment are error-prone. To establish and improve measurement of latent attributes it is presented in this paper the concept of a stochastic framework using the Rasch model for a wide range of independent variables referred to as an item bank. Based on an item bank, computerized adaptive testing (CAT) can be developed. A CAT system can converge into a sequence of items bracketing to convey information at a user's particular endorsement level. It is through item banking and CAT that the financial benefits of using the Rasch model in affective engineering can be realised

  2. 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

  3. 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.

    Science.gov (United States)

    Zucca, Alison; Lambert, Sylvie D; Boyes, Allison W; Pallant, Julie F

    2012-05-20

    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. 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. 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. 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 adaptive and maladaptive coping, extensive modifications were

  4. A Practitioner's Instrument for Measuring Secondary Mathematics Teachers' Beliefs Surrounding Learner-Centered Classroom Practice.

    Science.gov (United States)

    Lischka, Alyson E; Garner, Mary

    In this paper we present the development and validation of a Mathematics Teaching Pedagogical and Discourse Beliefs Instrument (MTPDBI), a 20 item partial-credit survey designed and analyzed using Rasch measurement theory. Items on the MTPDBI address beliefs about the nature of mathematics, teaching and learning mathematics, and classroom discourse practices. A Rasch partial credit model (Masters, 1982) was estimated from the pilot study data. Results show that item separation reliability is .96 and person separation reliability is .71. Other analyses indicate the instrument is a viable measure of secondary teachers' beliefs about reform-oriented mathematics teaching and learning. This instrument is proposed as a useful measure of teacher beliefs for those working with pre-service and in-service teacher development.

  5. The development of a short measure of physical function for hip OA HOOS-Physical Function Shortform (HOOS-PS)

    DEFF Research Database (Denmark)

    Davis, A M; Perruccio, A V; Canizares, M

    2008-01-01

    : The daily activity and sports and recreational items of the HOOS were reduced to five items achieving a feasible, short measure of physical function with interval level properties. This tool has potential for use as the function component of an OA severity scoring system. Further testing of this measure......OBJECTIVE: To derive a cross-culturally valid, short measure of physical function using function subscales (daily living and sports and recreation) of the Hip disability and Osteoarthritis Outcome Score (HOOS). METHODS: Rasch analysis was conducted on data from individuals from multiple countries...... who had hip osteoarthritis (OA). Fit of the data to the Rasch model was evaluated by model chi(2) and item fit statistics (chi(2), size of residual, and F-test). Differential item functioning was evaluated by gender, age and country. Unidimensionality was evaluated by factor analysis of residuals...

  6. Application of Rasch Measurement to Item Banking in Language Testing

    OpenAIRE

    中村, 優治

    2010-01-01

    ラッシュモデルの具体的応用例として考えられるのが,アイテムバンキングへの活用である.アイテムバンクは項目反応理論の分析手法を用いて統計処理を行った項目(アイテム)を蓄積したもので大規模な言語テストの開発のみならず,クラスルームにおける身近なテスト作成・テスト結果の考察にも威力を発揮するものである.本稿では理論的側面を概観したのち,50項目のテストデータを用いて,アイテムバンクの構築手順ならびにその長所,短所をのべ,さらに,実際の読解力テスト項目構築時の問題点などを指摘し今後の研究への示唆を行う....

  7. Aerial measuring system sensor modeling

    International Nuclear Information System (INIS)

    Detwiler, Rebecca

    2002-01-01

    The AMS fixed-wing and rotary-wing systems are critical National Nuclear Security Administration (NNSA) Emergency Response assets. This project is principally focused on the characterization of the sensors utilized with these systems via radiation transport calculations. The Monte Carlo N-Particle code (MCNP) which has been developed at Los Alamos National Laboratory was used to model the detector response of the AMS fixed wing and helicopter systems. To validate the calculations, benchmark measurements were made for simple source-detector configurations. The fixed-wing system is an important tool in response to incidents involving the release of mixed fission products (a commercial power reactor release), the threat or actual explosion of a Radiological Dispersal Device, and the loss or theft of a large industrial source (a radiography source). Calculations modeled the spectral response for the sensors contained, a 3-element NaI detector pod and HpGe detector, in the relevant energy range of 50 keV to 3 MeV. NaI detector responses were simulated for both point and distributed surface sources as a function of gamma energy and flying altitude. For point sources, photo-peak efficiencies were calculated for a zero radial distance and an offset equal to the altitude. For distributed sources approximating infinite plane, gross count efficiencies were calculated and normalized to a uniform surface deposition of 1 C i/m2

  8. Measuring Collective Efficacy: A Multilevel Measurement Model for Nested Data

    Science.gov (United States)

    Matsueda, Ross L.; Drakulich, Kevin M.

    2016-01-01

    This article specifies a multilevel measurement model for survey response when data are nested. The model includes a test-retest model of reliability, a confirmatory factor model of inter-item reliability with item-specific bias effects, an individual-level model of the biasing effects due to respondent characteristics, and a neighborhood-level…

  9. 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.

  10. Markov Decision Process Measurement Model.

    Science.gov (United States)

    LaMar, Michelle M

    2018-03-01

    Within-task actions can provide additional information on student competencies but are challenging to model. This paper explores the potential of using a cognitive model for decision making, the Markov decision process, to provide a mapping between within-task actions and latent traits of interest. Psychometric properties of the model are explored, and simulation studies report on parameter recovery within the context of a simple strategy game. The model is then applied to empirical data from an educational game. Estimates from the model are found to correlate more strongly with posttest results than a partial-credit IRT model based on outcome data alone.

  11. Dimensionality of the UWES-17: An item response modelling analysis

    OpenAIRE

    Deon P. de Bruin; Carin Hill; Carolina M. Henn; Klaus-Peter Muller

    2013-01-01

    Orientation: Questionnaires, particularly the Utrecht Work Engagement Scale (UWES-17), are an almost standard method by which to measure work engagement. Conflicting evidence regarding the dimensionality of the UWES-17 has led to confusion regarding the interpretation of scores. 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...

  12. Psychometric properties of the Spanish version of the UPPS-P Impulsive Behavior Scale: A Rasch rating scale analysis and confirmatory factor analysis.

    Science.gov (United States)

    Pilatti, Angelina; Lozano, Oscar M; Cyders, Melissa A

    2015-12-01

    The present study was aimed at determining the psychometric properties of the Spanish version of the UPPS-P Impulsive Behavior Scale in a sample of college students. Participants were 318 college students (36.2% men; mean age = 20.9 years, SD = 6.4 years). The psychometric properties of this Spanish version were analyzed using the Rasch model, and the factor structure was examined using confirmatory factor analysis. The verification of the global fit of the data showed adequate indexes for persons and items. The reliability estimates were high for both items and persons. Differential item functioning across gender was found for 23 items, which likely reflects known differences in impulsivity levels between men and women. The factor structure of the Spanish version of the UPPS-P replicates previous work with the original UPPS-P Scale. Overall, results suggest that test scores from the Spanish version of the UPPS-P show adequate psychometric properties to accurately assess the multidimensional model of impulsivity, which represents the most exhaustive measure of this construct. (c) 2015 APA, all rights reserved).

  13. The development of a short measure of physical function for knee OA KOOS-Physical Function Shortform (KOOS-PS) - an OARSI/OMERACT initiative

    DEFF Research Database (Denmark)

    Perruccio, A V; Stefan Lohmander, L; Canizares, M

    2008-01-01

    OBJECTIVE: To develop a short measure of physical function for knee osteoarthritis (OA) using multi-national data from individuals with varying degrees of severity of knee OA. METHODS: Rasch analysis, based on the partial credit model, was conducted on Knee injury and Osteoarthritis Outcome Score...... and Western Ontario McMaster Universities' Osteoarthritis Index data from individuals with knee OA, ranging from community to pre-total knee replacement samples from five countries. Fit of the data to the Rasch model was evaluated by overall model fit and item-level fit statistics (chi(2), size of residual, F....... RESULTS: Thirteen data sets were included (n=2145), with an age range of 26-95 years, and a male/female ratio of 1:1.4. The final model included seven of the original 22 items. From easiest to most difficult, the items (logit) were as follows: rising from bed (1.366), putting on socks/stockings (1...

  14. Directional wave measurements and modelling

    Digital Repository Service at National Institute of Oceanography (India)

    Anand, N.M.; Nayak, B.U.; Bhat, S.S.; SanilKumar, V.

    Some of the results obtained from analysis of the monsoon directional wave data measured over 4 years in shallow waters off the west coast of India are presented. The directional spectrum computed from the time series data seems to indicate...

  15. Classical test theory and Rasch analysis validation of the Upper Limb Functional Index in subjects with upper limb musculoskeletal disorders.

    Science.gov (United States)

    Bravini, Elisabetta; Franchignoni, Franco; Giordano, Andrea; Sartorio, Francesco; Ferriero, Giorgio; Vercelli, Stefano; Foti, Calogero

    2015-01-01

    To perform a comprehensive analysis of the psychometric properties and dimensionality of the Upper Limb Functional Index (ULFI) using both classical test theory and Rasch analysis (RA). Prospective, single-group observational design. Freestanding rehabilitation center. Convenience sample of Italian-speaking subjects with upper limb musculoskeletal disorders (N=174). Not applicable. The Italian version of the ULFI. Data were analyzed using parallel analysis, exploratory factor analysis, and RA for evaluating dimensionality, functioning of rating scale categories, item fit, hierarchy of item difficulties, and reliability indices. Parallel analysis revealed 2 factors explaining 32.5% and 10.7% of the response variance. RA confirmed the failure of the unidimensionality assumption, and 6 items out of the 25 misfitted the Rasch model. When the analysis was rerun excluding the misfitting items, the scale showed acceptable fit values, loading meaningfully to a single factor. Item separation reliability and person separation reliability were .98 and .89, respectively. Cronbach alpha was .92. RA revealed weakness of the scale concerning dimensionality and internal construct validity. However, a set of 19 ULFI items defined through the statistical process demonstrated a unidimensional structure, good psychometric properties, and clinical meaningfulness. These findings represent a useful starting point for further analyses of the tool (based on modern psychometric approaches and confirmatory factor analysis) in larger samples, including different patient populations and nationalities. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  16. Rolling Resistance Measurement and Model Development

    DEFF Research Database (Denmark)

    Andersen, Lasse Grinderslev; Larsen, Jesper; Fraser, Elsje Sophia

    2015-01-01

    There is an increased focus worldwide on understanding and modeling rolling resistance because reducing the rolling resistance by just a few percent will lead to substantial energy savings. This paper reviews the state of the art of rolling resistance research, focusing on measuring techniques, s......, surface and texture modeling, contact models, tire models, and macro-modeling of rolling resistance...

  17. Measuring Life Satisfaction in Parkinson's Disease and Healthy Controls Using the Satisfaction With Life Scale.

    Science.gov (United States)

    Løvereide, Lise; Hagell, Peter

    2016-01-01

    The 5-item Satisfaction With Life Scale (SWLS) was designed to measure general life satisfaction (LS). Here we examined the psychometric properties of the SWLS in a cohort of persons with Parkinson`s disease (PwPD) and age and gender matched individuals without PD. The SWLS was administered to PwPD and controls from the Norwegian ParkWest study at 5 and 7 years after the time of diagnosis. Data were analysed according to classical test theory (CTT) and Rasch measurement theory. CTT scaling assumptions for computation of a SWLS total score were met (corrected item-total correlations >0.58). The SWLS was reasonably well targeted to the sample and had good reliability (ordinal alpha, 0.92). The scale exhibited good fit to the Rasch model and successfully separated between 5 statistically distinct strata of people (levels of SWLS). The seven response categories did not work as intended and the scale may benefit from reduction to five response categories. There was no clinically significant differential item functioning. Separate analyses in PwPD and controls yielded very similar results to those from the pooled analysis. This study supports the SWLS as a valid instrument for measuring LS in PD and controls. However, Rasch analyses provided new insights into the performance and validity of the SWLS and identified areas for future revisions in order to further improve the scale.

  18. Aerosol behaviour modeling and measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gieseke, J A; Reed, L D [Batelle Memorial Institute, Columbus, OH (United States)

    1977-01-01

    Aerosol behavior within Liquid Metal Fast Breeder Reactor (LMFBR) containments is of critical importance since most of the radioactive species are expected to be associated with particulate forms and the mass of radiologically significant material leaked to the ambient atmosphere is directly related to the aerosol concentration airborne within the containment. Mathematical models describing the behavior of aerosols in closed environments, besides providing a direct means of assessing the importance of specific assumptions regarding accident sequences, will also serve as the basic tool with which to predict the consequences of various postulated accident situations. Consequently, considerable efforts have been recently directed toward the development of accurate and physically realistic theoretical aerosol behavior models. These models have accounted for various mechanisms affecting agglomeration rates of airborne particulate matter as well as particle removal rates from closed systems. In all cases, spatial variations within containments have been neglected and a well-mixed control volume has been assumed. Examples of existing computer codes formulated from the mathematical aerosol behavior models are the Brookhaven National Laboratory TRAP code, the PARDISEKO-II and PARDISEKO-III codes developed at Karlsruhe Nuclear Research Center, and the HAA-2, HAA-3, and HAA-3B codes developed by Atomics International. Because of their attractive short computation times, the HAA-3 and HAA-3B codes have been used extensively for safety analyses and are attractive candidates with which to demonstrate order of magnitude estimates of the effects of various physical assumptions. Therefore, the HAA-3B code was used as the nucleus upon which changes have been made to account for various physical mechanisms which are expected to be present in postulated accident situations and the latest of the resulting codes has been termed the HAARM-2 code. It is the primary purpose of the HAARM

  19. Measuring practical knowledge about balanced meals: development and validation of the brief PKB-7 scale.

    Science.gov (United States)

    Mötteli, S; Barbey, J; Keller, C; Bucher, T; Siegrist, M

    2016-04-01

    As a high-quality diet is associated with a lower risk for several diseases and all-cause mortality, current nutrition education tools provide people with information regarding how to build a healthy and a balanced meal. To assess this basic nutrition knowledge, the research aim was to develop and validate a brief scale to measure the Practical Knowledge about Balanced meals (PKB-7). A pool of 25 items was pretested with experts and laypeople before being tested on a random sample in Switzerland (n=517). For item selection, a Rasch model analysis was applied. The validity and reliability of the new scale were assessed by three additional studies including laypeople (n=597; n=145) and nutrition experts (n=59). The final scale consists of seven multiple-choice items, which met the assumptions of the Rasch model. The validity of the new scale was shown by several aspects: the Rasch model was replicated in a second study, and nutrition experts achieved significantly higher scores than laypeople (t(148)=20.27, Pbalanced meals based on current dietary guidelines. This brief and easy-to-use scale is intended for application in both research and practice.

  20. TE Wave Measurement and Modeling

    CERN Document Server

    Sikora, John P; Sonnad, Kiran G; Alesini, David; De Santis, Stefano

    2013-01-01

    In the TE wave method, microwaves are coupled into the beam-pipe and the effect of the electron cloud on these microwaves is measured. An electron cloud (EC) density can then be calculated from this measurement. There are two analysis methods currently in use. The first treats the microwaves as being transmitted from one point to another in the accelerator. The second more recent method, treats the beam-pipe as a resonant cavity. This paper will summarize the reasons for adopting the resonant TE wave analysis as well as give examples from CESRTA and DA{\\Phi}NE of resonant beam-pipe. The results of bead-pull bench measurements will show some possible standing wave patterns, including a cutoff mode (evanescent) where the field decreases exponentially with distance from the drive point. We will outline other recent developments in the TE wave method including VORPAL simulations of microwave resonances, as well as the simulation of transmission in the presence of both an electron cloud and magnetic fields.

  1. Assuring measurement quality in person-centred healthcare

    Science.gov (United States)

    Pendrill, L. R.

    2018-03-01

    Is it realistic to aspire to the same kind of quality-assurance of measurement in person-centred care, currently being implemented in healthcare globally, as is established in the physical sciences and engineering? Ensuring metrological comparability (‘traceability’) and reliably declaring measurement uncertainty when assessing patient ability or increased social capital are however challenging for subjective measurements often characterised by large dispersion. Drawing simple analogies between ‘instruments’ in the social sciences—questionnaires, ability tests, etc—and engineering instruments such as thermometers does not go far enough. A possible way forward, apparently equally applicable to both physical and social measurement, seems to be to model inferences in terms of performance metrics of a measurement system. Person-centred care needs person-centred measurement and a full picture of the measurement process when man acts as a measurement instrument is given in the present paper. This complements previous work by presenting the process, step by step, from the observed indication (e.g. probability of success, P success, of achieving a task), through restitution with Rasch measurement theory, to the measurand (e.g. task difficulty). Rasch invariant measure theory can yield quantities—‘latent’ (or ‘explanatory’) variables such as task challenge or person ability—with characteristics akin to those of physical quantities. Metrological references for comparability via traceability and reliable estimates of uncertainty and decision risks are then in reach even for perceptive measurements (and other qualitative properties). As a case study, the person-centred measurement of cognitive ability is examined, as part of the EU project EMPIR 15HLT04 NeuroMet, for Alzheimer’s, where better analysis of correlations with brain atrophy is enabled thanks to the Rasch metrological approach.

  2. Laser shaft alignment measurement model

    Science.gov (United States)

    Mo, Chang-tao; Chen, Changzheng; Hou, Xiang-lin; Zhang, Guoyu

    2007-12-01

    Laser beam's track which is on photosensitive surface of the a receiver will be closed curve, when driving shaft and the driven shaft rotate with same angular velocity and rotation direction. The coordinate of arbitrary point which is on the curve is decided by the relative position of two shafts. Basing on the viewpoint, a mathematic model of laser alignment is set up. By using a data acquisition system and a data processing model of laser alignment meter with single laser beam and a detector, and basing on the installation parameter of computer, the state parameter between two shafts can be obtained by more complicated calculation and correction. The correcting data of the four under chassis of the adjusted apparatus moving on the level and the vertical plane can be calculated. This will instruct us to move the apparatus to align the shafts.

  3. Towards an ICF-based clinical measure of functioning in people with ankylosing spondylitis: a methodological exploration.

    Science.gov (United States)

    Cieza, A; Hilfiker, R; Boonen, A; van der Heijde, D; Braun, J; Stucki, G

    2009-01-01

    To explore whether it is possible to construct clinical measures of functioning for patients with ankylosing spondylitis (AS) by integrating information obtained across categories of the International Classification of Functioning, Disability and Health (ICF). Sixty-eight ICF categories that were identified as relevant by patients with AS and that covered body functions, structures, and activity and participation were analysed based on the Rasch model for ordered response options. The following properties were studied: unidimensionality, reliability, fit of the ICF categories to the Rasch model, the appropriateness of the order of the response options of the ICF qualifier, and the targeting between the ICF categories and the person's abilities. After accounting for disordered thresholds and misfitting ICF categories, a clinical measure of functioning for AS was proposed that contained 64 ICF categories. On the basis of a transformation table, the raw scores obtained by adding the answers to the 64 ICF categories can be transformed to the Rasch logit scale and to a meaningful interval scale ranging from zero to 100. For the first time, it has been shown that clinical measures of functioning, in principle, can be constructed based on the comprehensive ICF framework covering body functions and structures and activities and participation domains. The results of this investigation are preliminary and must be validated, but they are promising and can contribute to the acceptance and usefulness of the ICF in clinical practice.

  4. Business Process Modelling for Measuring Quality

    NARCIS (Netherlands)

    Heidari, F.; Loucopoulos, P.; Brazier, F.M.

    2013-01-01

    Business process modelling languages facilitate presentation, communication and analysis of business processes with different stakeholders. This paper proposes an approach that drives specification and measurement of quality requirements and in doing so relies on business process models as

  5. Indoor MIMO Channel Measurement and Modeling

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Andersen, Jørgen Bach

    2005-01-01

    Forming accurate models of the multiple input multiple output (MIMO) channel is essential both for simulation as well as understanding of the basic properties of the channel. This paper investigates different known models using measurements obtained with a 16x32 MIMO channel sounder for the 5.8GHz...... band. The measurements were carried out in various indoor scenarios including both temporal and spatial aspects of channel changes. The models considered include the so-called Kronecker model, a model proposed by Weichselberger et. al., and a model involving the full covariance matrix, the most...

  6. Measurement properties of the CLOX Executive Clock Drawing Task in an inpatient stroke rehabilitation setting.

    Science.gov (United States)

    Zuverza-Chavarria, Virginia; Tsanadis, John

    2011-05-01

    The goal of this study was to explore the psychometric properties of the CLOX Executive Clock Drawing Task (Royall, Cordes, & Polk, 1998) in persons who had sustained a stroke and were receiving inpatient rehabilitation. Rasch modeling was utilized to examine the psychometric properties of the CLOX. Separate analyses were conducted for the free draw (CLOX 1) and copy (CLOX 2) portions of the measure to investigate each presentation mode independently. The sample consisted of 66 inpatient adults who had sustained a stroke. CLOX 1 met most Rasch model expectations for item fit, unidimensionality, test reliability, and sample targeting. CLOX 2 was less psychometrically sound and contained two items with significant misfit. CLOX 2 demonstrated a significant ceiling effect that resulted in poor sample targeting. CLOX 1 is a psychometrically sound screening instrument for assessing persons with stroke receiving inpatient rehabilitation. In addition to the psychometric weaknesses of CLOX 2, its interpretive yield is minimal and clinicians may consider omitting it. Recommendations are made for using the Rasch item-person maps in clinical practice.

  7. Measurement control program at model facility

    International Nuclear Information System (INIS)

    Schneider, R.A.

    1984-01-01

    A measurement control program for the model plant is described. The discussion includes the technical basis for such a program, the application of measurement control principles to each measurement, and the use of special experiments to estimate measurement error parameters for difficult-to-measure materials. The discussion also describes the statistical aspects of the program, and the documentation procedures used to record, maintain, and process the basic data

  8. Formal Definition of Measures for BPMN Models

    Science.gov (United States)

    Reynoso, Luis; Rolón, Elvira; Genero, Marcela; García, Félix; Ruiz, Francisco; Piattini, Mario

    Business process models are currently attaining more relevance, and more attention is therefore being paid to their quality. This situation led us to define a set of measures for the understandability of BPMN models, which is shown in a previous work. We focus on understandability since a model must be well understood before any changes are made to it. These measures were originally informally defined in natural language. As is well known, natural language is ambiguous and may lead to misunderstandings and a misinterpretation of the concepts captured by a measure and the way in which the measure value is obtained. This has motivated us to provide the formal definition of the proposed measures using OCL (Object Constraint Language) upon the BPMN (Business Process Modeling Notation) metamodel presented in this paper. The main advantages and lessons learned (which were obtained both from the current work and from previous works carried out in relation to the formal definition of other measures) are also summarized.

  9. Metrology of human-based and other qualitative measurements

    Science.gov (United States)

    Pendrill, Leslie; Petersson, Niclas

    2016-09-01

    The metrology of human-based and other qualitative measurements is in its infancy—concepts such as traceability and uncertainty are as yet poorly developed. This paper reviews how a measurement system analysis approach, particularly invoking as performance metric the ability of a probe (such as a human being) acting as a measurement instrument to make a successful decision, can enable a more general metrological treatment of qualitative observations. Measures based on human observations are typically qualitative, not only in sectors, such as health care, services and safety, where the human factor is obvious, but also in customer perception of traditional products of all kinds. A principal challenge is that the usual tools of statistics normally employed for expressing measurement accuracy and uncertainty will probably not work reliably if relations between distances on different portions of scales are not fully known, as is typical of ordinal or other qualitative measurements. A key enabling insight is to connect the treatment of decision risks associated with measurement uncertainty to generalized linear modelling (GLM). Handling qualitative observations in this way unites information theory, the perceptive identification and choice paradigms of psychophysics. The Rasch invariant measure psychometric GLM approach in particular enables a proper treatment of ordinal data; a clear separation of probe and item attribute estimates; simple expressions for instrument sensitivity; etc. Examples include two aspects of the care of breast cancer patients, from diagnosis to rehabilitation. The Rasch approach leads in turn to opportunities of establishing metrological references for quality assurance of qualitative measurements. In psychometrics, one could imagine a certified reference for knowledge challenge, for example, a particular concept in understanding physics or for product quality of a certain health care service. Multivariate methods, such as Principal Component

  10. Metrology of human-based and other qualitative measurements

    International Nuclear Information System (INIS)

    Pendrill, Leslie; Petersson, Niclas

    2016-01-01

    The metrology of human-based and other qualitative measurements is in its infancy—concepts such as traceability and uncertainty are as yet poorly developed. This paper reviews how a measurement system analysis approach, particularly invoking as performance metric the ability of a probe (such as a human being) acting as a measurement instrument to make a successful decision, can enable a more general metrological treatment of qualitative observations. Measures based on human observations are typically qualitative, not only in sectors, such as health care, services and safety, where the human factor is obvious, but also in customer perception of traditional products of all kinds. A principal challenge is that the usual tools of statistics normally employed for expressing measurement accuracy and uncertainty will probably not work reliably if relations between distances on different portions of scales are not fully known, as is typical of ordinal or other qualitative measurements. A key enabling insight is to connect the treatment of decision risks associated with measurement uncertainty to generalized linear modelling (GLM). Handling qualitative observations in this way unites information theory, the perceptive identification and choice paradigms of psychophysics. The Rasch invariant measure psychometric GLM approach in particular enables a proper treatment of ordinal data; a clear separation of probe and item attribute estimates; simple expressions for instrument sensitivity; etc. Examples include two aspects of the care of breast cancer patients, from diagnosis to rehabilitation. The Rasch approach leads in turn to opportunities of establishing metrological references for quality assurance of qualitative measurements. In psychometrics, one could imagine a certified reference for knowledge challenge, for example, a particular concept in understanding physics or for product quality of a certain health care service. Multivariate methods, such as Principal Component

  11. Analysis of Rater Agreement by Rasch and IRT Models

    DEFF Research Database (Denmark)

    Petersen, Jørgen Holm

    2013-01-01

    by obstetricians to asses the status of a fetus. Meta analyses of the randomized clinical trials have shown a 49% reduction in perinatal mortality on using the technique on high-risk pregnancies. It is clear from these considerations that the variations in effects of using the ultrasound technique may in part...

  12. Standard Model measurements with the ATLAS detector

    Directory of Open Access Journals (Sweden)

    Hassani Samira

    2015-01-01

    Full Text Available Various Standard Model measurements have been performed in proton-proton collisions at a centre-of-mass energy of √s = 7 and 8 TeV using the ATLAS detector at the Large Hadron Collider. A review of a selection of the latest results of electroweak measurements, W/Z production in association with jets, jet physics and soft QCD is given. Measurements are in general found to be well described by the Standard Model predictions.

  13. Measurement Model Specification Error in LISREL Structural Equation Models.

    Science.gov (United States)

    Baldwin, Beatrice; Lomax, Richard

    This LISREL study examines the robustness of the maximum likelihood estimates under varying degrees of measurement model misspecification. A true model containing five latent variables (two endogenous and three exogenous) and two indicator variables per latent variable was used. Measurement model misspecification considered included errors of…

  14. 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

  15. Radio propagation measurement and channel modelling

    CERN Document Server

    Salous, Sana

    2013-01-01

    While there are numerous books describing modern wireless communication systems that contain overviews of radio propagation and radio channel modelling, there are none that contain detailed information on the design, implementation and calibration of radio channel measurement equipment, the planning of experiments and the in depth analysis of measured data. The book would begin with an explanation of the fundamentals of radio wave propagation and progress through a series of topics, including the measurement of radio channel characteristics, radio channel sounders, measurement strategies

  16. Biases and power for groups comparison on subjective health measurements.

    Science.gov (United States)

    Hamel, Jean-François; Hardouin, Jean-Benoit; Le Neel, Tanguy; Kubis, Gildas; Roquelaure, Yves; Sébille, Véronique

    2012-01-01

    Subjective health measurements are increasingly used in clinical research, particularly for patient groups comparisons. Two main types of analytical strategies can be used for such data: so-called classical test theory (CTT), relying on observed scores and models coming from Item Response Theory (IRT) relying on a response model relating the items responses to a latent parameter, often called latent trait. Whether IRT or CTT would be the most appropriate method to compare two independent groups of patients on a patient reported outcomes measurement remains unknown and was investigated using simulations. For CTT-based analyses, groups comparison was performed using t-test on the scores. For IRT-based analyses, several methods were compared, according to whether the Rasch model was considered with random effects or with fixed effects, and the group effect was included as a covariate or not. Individual latent traits values were estimated using either a deterministic method or by stochastic approaches. Latent traits were then compared with a t-test. Finally, a two-steps method was performed to compare the latent trait distributions, and a Wald test was performed to test the group effect in the Rasch model including group covariates. The only unbiased IRT-based method was the group covariate Wald's test, performed on the random effects Rasch model. This model displayed the highest observed power, which was similar to the power using the score t-test. These results need to be extended to the case frequently encountered in practice where data are missing and possibly informative.

  17. Biases and power for groups comparison on subjective health measurements.

    Directory of Open Access Journals (Sweden)

    Jean-François Hamel

    Full Text Available Subjective health measurements are increasingly used in clinical research, particularly for patient groups comparisons. Two main types of analytical strategies can be used for such data: so-called classical test theory (CTT, relying on observed scores and models coming from Item Response Theory (IRT relying on a response model relating the items responses to a latent parameter, often called latent trait. Whether IRT or CTT would be the most appropriate method to compare two independent groups of patients on a patient reported outcomes measurement remains unknown and was investigated using simulations. For CTT-based analyses, groups comparison was performed using t-test on the scores. For IRT-based analyses, several methods were compared, according to whether the Rasch model was considered with random effects or with fixed effects, and the group effect was included as a covariate or not. Individual latent traits values were estimated using either a deterministic method or by stochastic approaches. Latent traits were then compared with a t-test. Finally, a two-steps method was performed to compare the latent trait distributions, and a Wald test was performed to test the group effect in the Rasch model including group covariates. The only unbiased IRT-based method was the group covariate Wald's test, performed on the random effects Rasch model. This model displayed the highest observed power, which was similar to the power using the score t-test. These results need to be extended to the case frequently encountered in practice where data are missing and possibly informative.

  18. Biases and Power for Groups Comparison on Subjective Health Measurements

    Science.gov (United States)

    Hamel, Jean-François; Hardouin, Jean-Benoit; Le Neel, Tanguy; Kubis, Gildas; Roquelaure, Yves; Sébille, Véronique

    2012-01-01

    Subjective health measurements are increasingly used in clinical research, particularly for patient groups comparisons. Two main types of analytical strategies can be used for such data: so-called classical test theory (CTT), relying on observed scores and models coming from Item Response Theory (IRT) relying on a response model relating the items responses to a latent parameter, often called latent trait. Whether IRT or CTT would be the most appropriate method to compare two independent groups of patients on a patient reported outcomes measurement remains unknown and was investigated using simulations. For CTT-based analyses, groups comparison was performed using t-test on the scores. For IRT-based analyses, several methods were compared, according to whether the Rasch model was considered with random effects or with fixed effects, and the group effect was included as a covariate or not. Individual latent traits values were estimated using either a deterministic method or by stochastic approaches. Latent traits were then compared with a t-test. Finally, a two-steps method was performed to compare the latent trait distributions, and a Wald test was performed to test the group effect in the Rasch model including group covariates. The only unbiased IRT-based method was the group covariate Wald’s test, performed on the random effects Rasch model. This model displayed the highest observed power, which was similar to the power using the score t-test. These results need to be extended to the case frequently encountered in practice where data are missing and possibly informative. PMID:23115620

  19. Measurement-based reliability/performability models

    Science.gov (United States)

    Hsueh, Mei-Chen

    1987-01-01

    Measurement-based models based on real error-data collected on a multiprocessor system are described. Model development from the raw error-data to the estimation of cumulative reward is also described. A workload/reliability model is developed based on low-level error and resource usage data collected on an IBM 3081 system during its normal operation in order to evaluate the resource usage/error/recovery process in a large mainframe system. Thus, both normal and erroneous behavior of the system are modeled. The results provide an understanding of the different types of errors and recovery processes. The measured data show that the holding times in key operational and error states are not simple exponentials and that a semi-Markov process is necessary to model the system behavior. A sensitivity analysis is performed to investigate the significance of using a semi-Markov process, as opposed to a Markov process, to model the measured system.

  20. Nonlinear Growth Models as Measurement Models: A Second-Order Growth Curve Model for Measuring Potential.

    Science.gov (United States)

    McNeish, Daniel; Dumas, Denis

    2017-01-01

    Recent methodological work has highlighted the promise of nonlinear growth models for addressing substantive questions in the behavioral sciences. In this article, we outline a second-order nonlinear growth model in order to measure a critical notion in development and education: potential. Here, potential is conceptualized as having three components-ability, capacity, and availability-where ability is the amount of skill a student is estimated to have at a given timepoint, capacity is the maximum amount of ability a student is predicted to be able to develop asymptotically, and availability is the difference between capacity and ability at any particular timepoint. We argue that single timepoint measures are typically insufficient for discerning information about potential, and we therefore describe a general framework that incorporates a growth model into the measurement model to capture these three components. Then, we provide an illustrative example using the public-use Early Childhood Longitudinal Study-Kindergarten data set using a Michaelis-Menten growth function (reparameterized from its common application in biochemistry) to demonstrate our proposed model as applied to measuring potential within an educational context. The advantage of this approach compared to currently utilized methods is discussed as are future directions and limitations.

  1. The patient satisfaction questionnaire of EUprimecare project: measurement properties.

    Science.gov (United States)

    Cimas, Marta; Ayala, Alba; García-Pérez, Sonia; Sarria-Santamera, Antonio; Forjaz, Maria João

    2016-06-01

    The measurement of patient satisfaction is considered an essential outcome indicator to evaluate health care quality. Patient satisfaction is considered a multi-dimensional construct, which would include a variety of domains. Although a large number of studies have proposed scales to measure patient satisfaction, there is a lack of psychometric information on them. This study aims to describe the psychometric properties of the Primary Care Satisfaction Scale (PCSS) of the EUprimecare project. A cross-sectional survey of patient satisfaction with primary care was carried out by telephone interview. Primary care services of Estonia, Finland, Germany, Hungary, Lithuania, Italy and Spain. A total of 3020 adult patients aged 18-65 years old attending primary care services. Classic psychometric properties were analysed and Rasch analysis was used to assess the following measurement properties: fit to the Rasch model; uni-dimensionality; reliability; differential item functioning (DIF) by gender, age, civil status, area of residency and country; local independency; adequacy of response scale; and scale targeting. To achieve good fit to the Rasch model, the original response scales of three items (1, 2 and 6) were rescored and Item 3 (waiting time in the room) was removed. The scale was uni-dimensional and Person Separation Index was 0.79, indicating a good reliability. All items were free from bias. PCSS linear measure displayed satisfactory convergent validity with overall satisfaction with primary care. PCSS, as a reliable and valid scale, could be used to measure patient satisfaction in primary care in Europe. © The Author 2016. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

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

    DEFF Research Database (Denmark)

    Lauridsen, Henrik Hein; Hartvigsen, Jan

    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...

  3. Model SH intelligent instrument for thickness measuring

    International Nuclear Information System (INIS)

    Liu Juntao; Jia Weizhuang; Zhao Yunlong

    1995-01-01

    The authors introduce Model SH Intelligent Instrument for thickness measuring by using principle of beta back-scattering and its application range, features, principle of operation, system design, calibration and specifications

  4. Smart Kinesthetic Measurement Model in Dance Composision

    OpenAIRE

    Triana, Dinny Devi

    2017-01-01

    This research aimed to discover a model of assessment that could measure kinesthetic intelligence in arranging a dance from several related variable, both direct variable and indirect variable. The research method used was a qualitative method using path analysis to determine the direct and indirect variable; therefore, the dominant variable that supported the measurement model of kinesthetic intelligence in arranging dance could be discovered. The population used was the students of the art ...

  5. Automated statistical modeling of analytical measurement systems

    International Nuclear Information System (INIS)

    Jacobson, J.J.

    1992-01-01

    The statistical modeling of analytical measurement systems at the Idaho Chemical Processing Plant (ICPP) has been completely automated through computer software. The statistical modeling of analytical measurement systems is one part of a complete quality control program used by the Remote Analytical Laboratory (RAL) at the ICPP. The quality control program is an integration of automated data input, measurement system calibration, database management, and statistical process control. The quality control program and statistical modeling program meet the guidelines set forth by the American Society for Testing Materials and American National Standards Institute. A statistical model is a set of mathematical equations describing any systematic bias inherent in a measurement system and the precision of a measurement system. A statistical model is developed from data generated from the analysis of control standards. Control standards are samples which are made up at precise known levels by an independent laboratory and submitted to the RAL. The RAL analysts who process control standards do not know the values of those control standards. The object behind statistical modeling is to describe real process samples in terms of their bias and precision and, to verify that a measurement system is operating satisfactorily. The processing of control standards gives us this ability

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

    Directory of Open Access Journals (Sweden)

    Lucas Primo de Carvalho Alves

    Full Text Available 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; p<0.00001. For the HAM-D6 model fit, mean (±SD of item residuals = 0.5 (±0.86; mean (±SD of person residuals = 0.15 (±0.91; χ2 = 56.13; p = 0.196. MFD ordered by crescent severity were depressed 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.

  7. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  8. Settings in Social Networks : a Measurement Model

    NARCIS (Netherlands)

    Schweinberger, Michael; Snijders, Tom A.B.

    2003-01-01

    A class of statistical models is proposed that aims to recover latent settings structures in social networks. Settings may be regarded as clusters of vertices. The measurement model is based on two assumptions. (1) The observed network is generated by hierarchically nested latent transitive

  9. Models Used for Measuring Customer Engagement

    Directory of Open Access Journals (Sweden)

    Mihai TICHINDELEAN

    2013-12-01

    Full Text Available The purpose of the paper is to define and measure the customer engagement as a forming element of the relationship marketing theory. In the first part of the paper, the authors review the marketing literature regarding the concept of customer engagement and summarize the main models for measuring it. One probability model (Pareto/NBD model and one parametric model (RFM model specific for the customer acquisition phase are theoretically detailed. The second part of the paper is an application of the RFM model; the authors demonstrate that there is no statistical significant variation within the clusters formed on two different data sets (training and test set if the cluster centroids of the training set are used as initial cluster centroids for the second test set.

  10. Theory-Based Parameterization of Semiotics for Measuring Pre-literacy Development

    Science.gov (United States)

    Bezruczko, N.

    2013-09-01

    A probabilistic model was applied to problem of measuring pre-literacy in young children. First, semiotic philosophy and contemporary cognition research were conceptually integrated to establish theoretical foundations for rating 14 characteristics of children's drawings and narratives (N = 120). Then ratings were transformed with a Rasch model, which estimated linear item parameter values that accounted for 79 percent of rater variance. Principle Components Analysis of item residual matrix confirmed variance remaining after item calibration was largely unsystematic. Validation analyses found positive correlations between semiotic measures and preschool literacy outcomes. Practical implications of a semiotics dimension for preschool practice were discussed.

  11. Theory-Based Parameterization of Semiotics for Measuring Pre-literacy Development

    International Nuclear Information System (INIS)

    Bezruczko, N

    2013-01-01

    A probabilistic model was applied to problem of measuring pre-literacy in young children. First, semiotic philosophy and contemporary cognition research were conceptually integrated to establish theoretical foundations for rating 14 characteristics of children's drawings and narratives (N = 120). Then ratings were transformed with a Rasch model, which estimated linear item parameter values that accounted for 79 percent of rater variance. Principle Components Analysis of item residual matrix confirmed variance remaining after item calibration was largely unsystematic. Validation analyses found positive correlations between semiotic measures and preschool literacy outcomes. Practical implications of a semiotics dimension for preschool practice were discussed

  12. Markowitz portfolio optimization model employing fuzzy measure

    Science.gov (United States)

    Ramli, Suhailywati; Jaaman, Saiful Hafizah

    2017-04-01

    Markowitz in 1952 introduced the mean-variance methodology for the portfolio selection problems. His pioneering research has shaped the portfolio risk-return model and become one of the most important research fields in modern finance. This paper extends the classical Markowitz's mean-variance portfolio selection model applying the fuzzy measure to determine the risk and return. In this paper, we apply the original mean-variance model as a benchmark, fuzzy mean-variance model with fuzzy return and the model with return are modeled by specific types of fuzzy number for comparison. The model with fuzzy approach gives better performance as compared to the mean-variance approach. The numerical examples are included to illustrate these models by employing Malaysian share market data.

  13. From Concrete to Abstract in the Measurement of Length

    International Nuclear Information System (INIS)

    Stephanou, Andreas; Fisher, William P Jr

    2013-01-01

    The concatenation of units of length is widely viewed as the paradigmatic expression of fundamental measurement. Survey, assessment, and test scores in educational and psychological measurement are often interpreted in ways that assume a concatenation of units to have been established, even though these assumptions are rarely stated or tested. A concatenation model for measurement is shown to be equivalent to a Rasch model: any two units of measurement placed end to end must together be of the same length as either one of them added to itself. This additive principle and a concatenation model of measurement together serve as a heuristic guide for organizing two experimental approaches to calibrating instruments for measuring length. The capacity to reproduce the unit of measurement from theory with no need for repeated empirical calibration experiments, as in the geometrical bisection of the line and the resultant halving of the length measure, is highlighted as essential to demonstrating a thorough understanding of the construct

  14. 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

  15. Integration of climatic indices in an objective probabilistic model for establishing and mapping viticultural climatic zones in a region

    Science.gov (United States)

    Moral, Francisco J.; Rebollo, Francisco J.; Paniagua, Luis L.; García, Abelardo; Honorio, Fulgencio

    2016-05-01

    Different climatic indices have been proposed to determine the wine suitability in a region. Some of them are related to the air temperature, but the hydric component of climate should also be considered which, in turn, is influenced by the precipitation during the different stages of the grapevine growing and ripening periods. In this study, we propose using the information obtained from ten climatic indices [heliothermal index (HI), cool night index (CI), dryness index (DI), growing season temperature (GST), the Winkler index (WI), September mean thermal amplitude (MTA), annual precipitation (AP), precipitation during flowering (PDF), precipitation before flowering (PBF), and summer precipitation (SP)] as inputs in an objective and probabilistic model, the Rasch model, with the aim of integrating the individual effects of them, obtaining the climate data that summarize all main climatic indices, which could influence on wine suitability from a climate viewpoint, and utilizing the Rasch measures to generate homogeneous climatic zones. The use of the Rasch model to estimate viticultural climatic suitability constitutes a new application of great practical importance, enabling to rationally determine locations in a region where high viticultural potential exists and establishing a ranking of the climatic indices which exerts an important influence on wine suitability in a region. Furthermore, from the measures of viticultural climatic suitability at some locations, estimates can be computed using a geostatistical algorithm, and these estimates can be utilized to map viticultural climatic zones in a region. To illustrate the process, an application to Extremadura, southwestern Spain, is shown.

  16. Testing substellar models with dynamical mass measurements

    Directory of Open Access Journals (Sweden)

    Liu M.C.

    2011-07-01

    Full Text Available We have been using Keck laser guide star adaptive optics to monitor the orbits of ultracool binaries, providing dynamical masses at lower luminosities and temperatures than previously available and enabling strong tests of theoretical models. We have identified three specific problems with theory: (1 We find that model color–magnitude diagrams cannot be reliably used to infer masses as they do not accurately reproduce the colors of ultracool dwarfs of known mass. (2 Effective temperatures inferred from evolutionary model radii are typically inconsistent with temperatures derived from fitting atmospheric models to observed spectra by 100–300 K. (3 For the only known pair of field brown dwarfs with a precise mass (3% and age determination (≈25%, the measured luminosities are ~2–3× higher than predicted by model cooling rates (i.e., masses inferred from Lbol and age are 20–30% larger than measured. To make progress in understanding the observed discrepancies, more mass measurements spanning a wide range of luminosity, temperature, and age are needed, along with more accurate age determinations (e.g., via asteroseismology for primary stars with brown dwarf binary companions. Also, resolved optical and infrared spectroscopy are needed to measure lithium depletion and to characterize the atmospheres of binary components in order to better assess model deficiencies.

  17. Measures of Quality in Business Process Modelling

    Directory of Open Access Journals (Sweden)

    Radek Hronza

    2015-06-01

    Full Text Available Business process modelling and analysing is undoubtedly one of the most important parts of Applied (Business Informatics. Quality of business process models (diagrams is crucial for any purpose in this area. The goal of a process analyst’s work is to create generally understandable, explicit and error free models. If a process is properly described, created models can be used as an input into deep analysis and optimization. It can be assumed that properly designed business process models (similarly as in the case of correctly written algorithms contain characteristics that can be mathematically described. Besides it will be possible to create a tool that will help process analysts to design proper models. As part of this review will be conducted systematic literature review in order to find and analyse business process model’s design and business process model’s quality measures. It was found that mentioned area had already been the subject of research investigation in the past. Thirty-three suitable scietific publications and twenty-two quality measures were found. Analysed scientific publications and existing quality measures do not reflect all important attributes of business process model’s clarity, simplicity and completeness. Therefore it would be appropriate to add new measures of quality.

  18. A stochastic model for quantum measurement

    International Nuclear Information System (INIS)

    Budiyono, Agung

    2013-01-01

    We develop a statistical model of microscopic stochastic deviation from classical mechanics based on a stochastic process with a transition probability that is assumed to be given by an exponential distribution of infinitesimal stationary action. We apply the statistical model to stochastically modify a classical mechanical model for the measurement of physical quantities reproducing the prediction of quantum mechanics. The system+apparatus always has a definite configuration at all times, as in classical mechanics, fluctuating randomly following a continuous trajectory. On the other hand, the wavefunction and quantum mechanical Hermitian operator corresponding to the physical quantity arise formally as artificial mathematical constructs. During a single measurement, the wavefunction of the whole system+apparatus evolves according to a Schrödinger equation and the configuration of the apparatus acts as the pointer of the measurement so that there is no wavefunction collapse. We will also show that while the outcome of each single measurement event does not reveal the actual value of the physical quantity prior to measurement, its average in an ensemble of identical measurements is equal to the average of the actual value of the physical quantity prior to measurement over the distribution of the configuration of the system. (paper)

  19. Measuring and modeling water imbibition into tuff

    International Nuclear Information System (INIS)

    Peters, R.R.; Klavetter, E.A.; George, J.T.; Gauthier, J.H.

    1986-01-01

    Yucca Mountain (Nevada) is being investigated as a potential site for a high-level-radioactive-waste repository. The site combines a partially saturated hydrologic system and a stratigraphy of fractured, welded and nonwelded tuffs. The long time scale for site hydrologic phenomena makes their direct measurement prohibitive. Also, modeling is difficult because the tuffs exhibit widely varying, and often highly nonlinear hydrologic properties. To increase a basic understanding of both the hydrologic properties of tuffs and the modeling of flow in partially saturated regimes, the following tasks were performed, and the results are reported: (1) Laboratory Experiment: Water imbibition into a cylinder of tuff (taken from Yucca Mountain drill core) was measured by immersing one end of a dry sample in water and noting its weight at various times. The flow of water was approximately one-dimensional, filling the sample from bottom to top. (2) Computer Simulation: The experiment was modeled using TOSPAC (a one-dimensional, finite-difference computer program for simulating water flow in partially saturated, fractured, layered media) with data currently considered for use in site-scale modeling of a repository in Yucca Mountain. The measurements and the results of the modeling are compared. Conclusions are drawn with respect to the accuracy of modeling transient flow in a partially saturated, porous medium using a one-dimensional model and currently available hydrologic-property data

  20. Using Rasch Analysis to Evaluate the Reliability and Validity of the Swallowing Quality of Life Questionnaire: An Item Response Theory Approach.

    Science.gov (United States)

    Cordier, Reinie; Speyer, Renée; Schindler, Antonio; Michou, Emilia; Heijnen, Bas Joris; Baijens, Laura; Karaduman, Ayşe; Swan, Katina; Clavé, Pere; Joosten, Annette Veronica

    2018-02-01

    The Swallowing Quality of Life questionnaire (SWAL-QOL) is widely used clinically and in research to evaluate quality of life related to swallowing difficulties. It has been described as a valid and reliable tool, but was developed and tested using classic test theory. This study describes the reliability and validity of the SWAL-QOL using item response theory (IRT; Rasch analysis). SWAL-QOL data were gathered from 507 participants at risk of oropharyngeal dysphagia (OD) across four European countries. OD was confirmed in 75.7% of participants via videofluoroscopy and/or fiberoptic endoscopic evaluation, or a clinical diagnosis based on meeting selected criteria. Patients with esophageal dysphagia were excluded. Data were analysed using Rasch analysis. Item and person reliability was good for all the items combined. However, person reliability was poor for 8 subscales and item reliability was poor for one subscale. Eight subscales exhibited poor person separation and two exhibited poor item separation. Overall item and person fit statistics were acceptable. However, at an individual item fit level results indicated unpredictable item responses for 28 items, and item redundancy for 10 items. The item-person dimensionality map confirmed these findings. Results from the overall Rasch model fit and Principal Component Analysis were suggestive of a second dimension. For all the items combined, none of the item categories were 'category', 'threshold' or 'step' disordered; however, all subscales demonstrated category disordered functioning. Findings suggest an urgent need to further investigate the underlying structure of the SWAL-QOL and its psychometric characteristics using IRT.

  1. 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)

    Pey Tee, Oon; Subramaniam, R.

    2018-02-01

    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 journal literature. The Rasch model was used to analyse the data, and the findings have shed some useful light on not only how the Western and Asian students responded on a comparative basis in the various scales related to attitudes but also on the validity, reliability, and unidimensionality of the attitudes instrument used in TIMSS 2011. There may be a need for TIMSS test developers to consider doing away with negatively phrased items in the attitudes instrument and phrasing these positively as the Rasch framework shows that response bias is associated with these statements.

  2. THE BUSINESS MODEL AND FINANCIAL ASSETS MEASUREMENT

    OpenAIRE

    NICULA Ileana

    2012-01-01

    The paper work analyses some aspects regarding the implementation of IFRS 9, the relationship between the business model approach and the assets classification and measurement. It does not discuss the cash flows characteristics, another important aspect of assets classification, or the reclassifications. The business model is related to some characteristics of the banks (opaqueness, leverage ratio, compliance to capital, sound liquidity requirements and risk management) and to Special Purpose...

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Measuring the impact of health problems among adults with limited mobility in Thailand: further validation of the Perceived Impact of Problem Profile

    Directory of Open Access Journals (Sweden)

    Manderson Lenore

    2008-01-01

    Full Text Available Abstract Background The Perceived Impact of Problem Profile (PIPP was developed to provide a tool for measuring the impact of a health condition from the individual's perspective, using the ICF model as a framework. One of the aims of the ICF is to enable the comparison of data across countries, however, relatively little is known about the subjective experience of disability in middle and low-income countries. The aim of this study was to assess the validity of the Perceived Impact of Problem Profile (PIPP for use among adults with a disability in Thailand using Rasch analysis. Methods A total of 210 adults with mobility impairment from the urban, rural and remote areas of northeast Thailand completed the PIPP, which contains 23 items assessing both impact and distress across five key domains (Self-care, Mobility, Participation, Relationships, and Psychological Well-being. Rasch analysis, using RUMM2020, was conducted to assess the internal validity and psychometric properties of the PIPP Impact subscales. Validation of the PIPP Impact scales was conducted by comparing scores across the different response levels of the EQ5D items. Results Rasch analysis indicated that participants did not clearly differentiate between 'impact' and 'distress,' the two aspects assessed by the PIPP. Further analyses were therefore limited to the PIPP Impact subscales. These showed adequate psychometric properties, demonstrating fit to the Rasch model and good person separation reliability. Preliminary validity testing using the EQ5D items provided support for the PIPP Impact subscales. Conclusion The results provide further support for the psychometric properties of the PIPP Impact scales and indicate that it is a suitable tool for use among adults with a locomotor disability in Thailand. Further research is needed to validate the PIPP across different cultural contexts and health conditions and to assess the usefulness of separate Impact and Distress subscales.

  5. Measuring the impact of health problems among adults with limited mobility in Thailand: further validation of the Perceived Impact of Problem Profile

    Science.gov (United States)

    Misajon, RoseAnne; Pallant, Julie F; Manderson, Lenore; Chirawatkul, Siriporn

    2008-01-01

    Background The Perceived Impact of Problem Profile (PIPP) was developed to provide a tool for measuring the impact of a health condition from the individual's perspective, using the ICF model as a framework. One of the aims of the ICF is to enable the comparison of data across countries, however, relatively little is known about the subjective experience of disability in middle and low-income countries. The aim of this study was to assess the validity of the Perceived Impact of Problem Profile (PIPP) for use among adults with a disability in Thailand using Rasch analysis. Methods A total of 210 adults with mobility impairment from the urban, rural and remote areas of northeast Thailand completed the PIPP, which contains 23 items assessing both impact and distress across five key domains (Self-care, Mobility, Participation, Relationships, and Psychological Well-being). Rasch analysis, using RUMM2020, was conducted to assess the internal validity and psychometric properties of the PIPP Impact subscales. Validation of the PIPP Impact scales was conducted by comparing scores across the different response levels of the EQ5D items. Results Rasch analysis indicated that participants did not clearly differentiate between 'impact' and 'distress,' the two aspects assessed by the PIPP. Further analyses were therefore limited to the PIPP Impact subscales. These showed adequate psychometric properties, demonstrating fit to the Rasch model and good person separation reliability. Preliminary validity testing using the EQ5D items provided support for the PIPP Impact subscales. Conclusion The results provide further support for the psychometric properties of the PIPP Impact scales and indicate that it is a suitable tool for use among adults with a locomotor disability in Thailand. Further research is needed to validate the PIPP across different cultural contexts and health conditions and to assess the usefulness of separate Impact and Distress subscales. PMID:18208616

  6. Causal Measurement Models: Can Criticism Stimulate Clarification?

    Science.gov (United States)

    Markus, Keith A.

    2016-01-01

    In their 2016 work, Aguirre-Urreta et al. provided a contribution to the literature on causal measurement models that enhances clarity and stimulates further thinking. Aguirre-Urreta et al. presented a form of statistical identity involving mapping onto the portion of the parameter space involving the nomological net, relationships between the…

  7. Model measurements for new accelerating techniques

    International Nuclear Information System (INIS)

    Aronson, S.; Haseroth, H.; Knott, J.; Willis, W.

    1988-06-01

    We summarize the work carried out for the past two years, concerning some different ways for achieving high-field gradients, particularly in view of future linear lepton colliders. These studies and measurements on low power models concern the switched power principle and multifrequency excitation of resonant cavities. 15 refs., 12 figs

  8. Interpreting, measuring, and modeling soil respiration

    Science.gov (United States)

    Michael G. Ryan; Beverly E. Law

    2005-01-01

    This paper reviews the role of soil respiration in determining ecosystem carbon balance, and the conceptual basis for measuring and modeling soil respiration. We developed it to provide background and context for this special issue on soil respiration and to synthesize the presentations and discussions at the workshop. Soil respiration is the largest component of...

  9. Using DORIS measurements for ionosphere modeling

    Science.gov (United States)

    Dettmering, Denise; Schmidt, Michael; Limberger, Marco

    2013-04-01

    Nowadays, most of the ionosphere models used in geodesy are based on terrestrial GNSS measurements and describe the Vertical Total Electron Content (VTEC) depending on longitude, latitude, and time. Since modeling the height distribution of the electrons is difficult due to the measurement geometry, the VTEC maps are based on the the assumption of a single-layer ionosphere. Moreover, the accuracy of the VTEC maps is different for different regions of the Earth, because the GNSS stations are unevenly distributed over the globe and some regions (especially the ocean areas) are not very well covered by observations. To overcome the unsatisfying measurement geometry of the terrestrial GNSS measurements and to take advantage of the different sensitivities of other space-geodetic observation techniques, we work on the development of multi-dimensional models of the ionosphere from the combination of modern space-geodetic satellite techniques. Our approach consists of a given background model and an unknown correction part expanded in terms of B-spline functions. Different space-geodetic measurements are used to estimate the unknown model coefficients. In order to take into account the different accuracy levels of the observations, a Variance Component Estimation (VCE) is applied. We already have proven the usefulness of radio occultation data from space-borne GPS receivers and of two-frequency altimetry data. Currently, we test the capability of DORIS observations to derive ionospheric parameters such as VTEC. Although DORIS was primarily designed for precise orbit computation of satellites, it can be used as a tool to study the Earth's ionosphere. The DORIS ground beacons are almost globally distributed and the system is on board of various Low Earth Orbiters (LEO) with different orbit heights, such as Jason-2, Cryosat-2, and HY-2. The last generation of DORIS receivers directly provides phase measurements on two frequencies. In this contribution, we test the DORIS

  10. ATLAS MDT neutron sensitivity measurement and modeling

    International Nuclear Information System (INIS)

    Ahlen, S.; Hu, G.; Osborne, D.; Schulz, A.; Shank, J.; Xu, Q.; Zhou, B.

    2003-01-01

    The sensitivity of the ATLAS precision muon detector element, the Monitored Drift Tube (MDT), to fast neutrons has been measured using a 5.5 MeV Van de Graaff accelerator. The major mechanism of neutron-induced signals in the drift tubes is the elastic collisions between the neutrons and the gas nuclei. The recoil nuclei lose kinetic energy in the gas and produce the signals. By measuring the ATLAS drift tube neutron-induced signal rate and the total neutron flux, the MDT neutron signal sensitivities were determined for different drift gas mixtures and for different neutron beam energies. We also developed a sophisticated simulation model to calculate the neutron-induced signal rate and signal spectrum for ATLAS MDT operation configurations. The calculations agree with the measurements very well. This model can be used to calculate the neutron sensitivities for different gaseous detectors and for neutron energies above those available to this experiment

  11. Nonclassical measurements errors in nonlinear models

    DEFF Research Database (Denmark)

    Madsen, Edith; Mulalic, Ismir

    Discrete choice models and in particular logit type models play an important role in understanding and quantifying individual or household behavior in relation to transport demand. An example is the choice of travel mode for a given trip under the budget and time restrictions that the individuals...... estimates of the income effect it is of interest to investigate the magnitude of the estimation bias and if possible use estimation techniques that take the measurement error problem into account. We use data from the Danish National Travel Survey (NTS) and merge it with administrative register data...... that contains very detailed information about incomes. This gives a unique opportunity to learn about the magnitude and nature of the measurement error in income reported by the respondents in the Danish NTS compared to income from the administrative register (correct measure). We find that the classical...

  12. 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

  13. Varying coefficients model with measurement error.

    Science.gov (United States)

    Li, Liang; Greene, Tom

    2008-06-01

    We propose a semiparametric partially varying coefficient model to study the relationship between serum creatinine concentration and the glomerular filtration rate (GFR) among kidney donors and patients with chronic kidney disease. A regression model is used to relate serum creatinine to GFR and demographic factors in which coefficient of GFR is expressed as a function of age to allow its effect to be age dependent. GFR measurements obtained from the clearance of a radioactively labeled isotope are assumed to be a surrogate for the true GFR, with the relationship between measured and true GFR expressed using an additive error model. We use locally corrected score equations to estimate parameters and coefficient functions, and propose an expected generalized cross-validation (EGCV) method to select the kernel bandwidth. The performance of the proposed methods, which avoid distributional assumptions on the true GFR and residuals, is investigated by simulation. Accounting for measurement error using the proposed model reduced apparent inconsistencies in the relationship between serum creatinine and GFR among different clinical data sets derived from kidney donor and chronic kidney disease source populations.

  14. Mathematical model of radon activity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Paschuk, Sergei A.; Correa, Janine N.; Kappke, Jaqueline; Zambianchi, Pedro, E-mail: sergei@utfpr.edu.br, E-mail: janine_nicolosi@hotmail.com [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Denyak, Valeriy, E-mail: denyak@gmail.com [Instituto de Pesquisa Pele Pequeno Principe, Curitiba, PR (Brazil)

    2015-07-01

    Present work describes a mathematical model that quantifies the time dependent amount of {sup 222}Rn and {sup 220}Rn altogether and their activities within an ionization chamber as, for example, AlphaGUARD, which is used to measure activity concentration of Rn in soil gas. The differential equations take into account tree main processes, namely: the injection of Rn into the cavity of detector by the air pump including the effect of the traveling time Rn takes to reach the chamber; Rn release by the air exiting the chamber; and radioactive decay of Rn within the chamber. Developed code quantifies the activity of {sup 222}Rn and {sup 220}Rn isotopes separately. Following the standard methodology to measure Rn activity in soil gas, the air pump usually is turned off over a period of time in order to avoid the influx of Rn into the chamber. Since {sup 220}Rn has a short half-life time, approximately 56s, the model shows that after 7 minutes the activity concentration of this isotope is null. Consequently, the measured activity refers to {sup 222}Rn, only. Furthermore, the model also addresses the activity of {sup 220}Rn and {sup 222}Rn progeny, which being metals represent potential risk of ionization chamber contamination that could increase the background of further measurements. Some preliminary comparison of experimental data and theoretical calculations is presented. Obtained transient and steady-state solutions could be used for planning of Rn in soil gas measurements as well as for accuracy assessment of obtained results together with efficiency evaluation of chosen measurements procedure. (author)

  15. Radiation budget measurement/model interface

    Science.gov (United States)

    Vonderhaar, T. H.; Ciesielski, P.; Randel, D.; Stevens, D.

    1983-01-01

    This final report includes research results from the period February, 1981 through November, 1982. Two new results combine to form the final portion of this work. They are the work by Hanna (1982) and Stevens to successfully test and demonstrate a low-order spectral climate model and the work by Ciesielski et al. (1983) to combine and test the new radiation budget results from NIMBUS-7 with earlier satellite measurements. Together, the two related activities set the stage for future research on radiation budget measurement/model interfacing. Such combination of results will lead to new applications of satellite data to climate problems. The objectives of this research under the present contract are therefore satisfied. Additional research reported herein includes the compilation and documentation of the radiation budget data set a Colorado State University and the definition of climate-related experiments suggested after lengthy analysis of the satellite radiation budget experiments.

  16. Measuring Visual Closeness of 3-D Models

    KAUST Repository

    Gollaz Morales, Jose Alejandro

    2012-09-01

    Measuring visual closeness of 3-D models is an important issue for different problems and there is still no standardized metric or algorithm to do it. The normal of a surface plays a vital role in the shading of a 3-D object. Motivated by this, we developed two applications to measure visualcloseness, introducing normal difference as a parameter in a weighted metric in Metro’s sampling approach to obtain the maximum and mean distance between 3-D models using 3-D and 6-D correspondence search structures. A visual closeness metric should provide accurate information on what the human observers would perceive as visually close objects. We performed a validation study with a group of people to evaluate the correlation of our metrics with subjective perception. The results were positive since the metrics predicted the subjective rankings more accurately than the Hausdorff distance.

  17. Estimators for longitudinal latent exposure models: examining measurement model assumptions.

    Science.gov (United States)

    Sánchez, Brisa N; Kim, Sehee; Sammel, Mary D

    2017-06-15

    Latent variable (LV) models are increasingly being used in environmental epidemiology as a way to summarize multiple environmental exposures and thus minimize statistical concerns that arise in multiple regression. LV models may be especially useful when multivariate exposures are collected repeatedly over time. LV models can accommodate a variety of assumptions but, at the same time, present the user with many choices for model specification particularly in the case of exposure data collected repeatedly over time. For instance, the user could assume conditional independence of observed exposure biomarkers given the latent exposure and, in the case of longitudinal latent exposure variables, time invariance of the measurement model. Choosing which assumptions to relax is not always straightforward. We were motivated by a study of prenatal lead exposure and mental development, where assumptions of the measurement model for the time-changing longitudinal exposure have appreciable impact on (maximum-likelihood) inferences about the health effects of lead exposure. Although we were not particularly interested in characterizing the change of the LV itself, imposing a longitudinal LV structure on the repeated multivariate exposure measures could result in high efficiency gains for the exposure-disease association. We examine the biases of maximum likelihood estimators when assumptions about the measurement model for the longitudinal latent exposure variable are violated. We adapt existing instrumental variable estimators to the case of longitudinal exposures and propose them as an alternative to estimate the health effects of a time-changing latent predictor. We show that instrumental variable estimators remain unbiased for a wide range of data generating models and have advantages in terms of mean squared error. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Measured, modeled, and causal conceptions of fitness

    Science.gov (United States)

    Abrams, Marshall

    2012-01-01

    This paper proposes partial answers to the following questions: in what senses can fitness differences plausibly be considered causes of evolution?What relationships are there between fitness concepts used in empirical research, modeling, and abstract theoretical proposals? How does the relevance of different fitness concepts depend on research questions and methodological constraints? The paper develops a novel taxonomy of fitness concepts, beginning with type fitness (a property of a genotype or phenotype), token fitness (a property of a particular individual), and purely mathematical fitness. Type fitness includes statistical type fitness, which can be measured from population data, and parametric type fitness, which is an underlying property estimated by statistical type fitnesses. Token fitness includes measurable token fitness, which can be measured on an individual, and tendential token fitness, which is assumed to be an underlying property of the individual in its environmental circumstances. Some of the paper's conclusions can be outlined as follows: claims that fitness differences do not cause evolution are reasonable when fitness is treated as statistical type fitness, measurable token fitness, or purely mathematical fitness. Some of the ways in which statistical methods are used in population genetics suggest that what natural selection involves are differences in parametric type fitnesses. Further, it's reasonable to think that differences in parametric type fitness can cause evolution. Tendential token fitnesses, however, are not themselves sufficient for natural selection. Though parametric type fitnesses are typically not directly measurable, they can be modeled with purely mathematical fitnesses and estimated by statistical type fitnesses, which in turn are defined in terms of measurable token fitnesses. The paper clarifies the ways in which fitnesses depend on pragmatic choices made by researchers. PMID:23112804

  19. Thermal effects in shales: measurements and modeling

    International Nuclear Information System (INIS)

    McKinstry, H.A.

    1977-01-01

    Research is reported concerning thermal and physical measurements and theoretical modeling relevant to the storage of radioactive wastes in a shale. Reference thermal conductivity measurements are made at atmospheric pressure in a commercial apparatus; and equipment for permeability measurements has been developed, and is being extended with respect to measurement ranges. Thermal properties of shales are being determined as a function of temperature and pressures. Apparatus was developed to measure shales in two different experimental configurations. In the first, a disk 15 mm in diameter of the material is measured by a steady state technique using a reference material to measure the heat flow within the system. The sample is sandwiched between two disks of a reference material (single crystal quartz is being used initially as reference material). The heat flow is determined twice in order to determine that steady state conditions prevail; the temperature drop over the two references is measured. When these indicate an equal heat flow, the thermal conductivity of the sample can be calculated from the temperature difference of the two faces. The second technique is for determining effect of temperature in a water saturated shale on a larger scale. Cylindrical shale (or siltstone) specimens that are being studied (large for a laboratory sample) are to be heated electrically at the center, contained in a pressure vessel that will maintain a fixed water pressure around it. The temperature is monitored at many points within the shale sample. The sample dimensions are 25 cm diameter, 20 cm long. A micro computer system has been constructed to monitor 16 thermocouples to record variation of temperature distribution with time

  20. Self-report measure of financial exploitation of older adults.

    Science.gov (United States)

    Conrad, Kendon J; Iris, Madelyn; Ridings, John W; Langley, Kate; Wilber, Kathleen H

    2010-12-01

    this study was designed to improve the measurement of financial exploitation (FE) by testing psychometric properties of the older adult financial exploitation measure (OAFEM), a client self-report instrument. rasch item response theory and traditional validation approaches were used. Questionnaires were administered by 22 adult protective services investigators from 7 agencies in Illinois to 227 substantiated abuse clients. Analyses included tests for dimensionality, model fit, and additional construct validation. Results from the OAFEM were also compared with the substantiation decision of abuse and with investigators' assessments of FE using a staff report version. Hypotheses were generated to test hypothesized relationships. the OAFEM, including the original 79-, 54-, and 30-item measures, met stringent Rasch analysis fit and unidimensionality criteria and had high internal consistency and item reliability. The validation results were supportive, while leading to reconsideration of aspects of the hypothesized theoretical hierarchy. Thresholds were suggested to demonstrate levels of severity. the measure is now available to aid in the assessment of FE of older adults by both clinicians and researchers. Theoretical refinements developed using the empirically generated item hierarchy may help to improve assessment and intervention.

  1. Advances in fluid modeling and turbulence measurements

    International Nuclear Information System (INIS)

    Wada, Akira; Ninokata, Hisashi; Tanaka, Nobukazu

    2002-01-01

    The context of this book consists of four fields: Environmental Fluid Mechanics; Industrial Fluid Mechanics; Fundamentals of Fluid Mechanics; and Turbulence Measurements. Environmental Fluid Mechanics includes free surface flows in channels, rivers, seas, and estuaries. It also discusses wind engineering issues, ocean circulation model and dispersion problems in atmospheric, water and ground water environments. In Industrial Fluid Mechanics, fluid phenomena in energy exchanges, modeling of turbulent two- or multi-phase flows, swirling flows, flows in combustors, variable density flows and reacting flows, flows in turbo-machines, pumps and piping systems, and fluid-structure interaction are discussed. In Fundamentals of Fluid Mechanics, progress in modeling turbulent flows and heat/mass transfers, computational fluid dynamics/numerical techniques, parallel computing algorithms, applications of chaos/fractal theory in turbulence are reported. In Turbulence Measurements, experimental studies of turbulent flows, experimental and post-processing techniques, quantitative and qualitative flow visualization techniques are discussed. Separate abstracts were presented for 15 of the papers in this issue. The remaining 89 were considered outside the subject scope of INIS. (J.P.N.)

  2. Beta measurements and modeling the Tevatron

    International Nuclear Information System (INIS)

    Gelfand, N.M.

    1993-06-01

    The Tevatron collider is now able with two low-β (β*=0.25--0.5m) interaction regions denoted as B0 and D0. This lattice allows independent operation of the interaction regions which required that the previous collider lattice, used in 1988--89, had to be modified. In order to see how well the lattice conforms to the design, measurements of the β function have been carried out at 15 locations in the new Tevatron collider lattice. Agreement can be obtained between the measurements and a computer model for the Tevatron, based on the design, only if the strengths of the gradients in the quadrupoles in the low-β triplet are allowed to differ from their design values. It is also observed that the lattice is very sensitive to the precise values of the gradients in these magnets

  3. Electrostatic sensor modeling for torque measurements

    Directory of Open Access Journals (Sweden)

    M. Mika

    2017-09-01

    Full Text Available Torque load measurements play an important part in various engineering applications, as for automotive industry, in which the drive torque of a motor has to be determined. A widely used measuring method are strain gauges. A thin flexible foil, which supports a metallic pattern, is glued to the surface of the object the torque is being applied to. In case of a deformation due to the torque load, the change in the electrical resistance is measured. With the combination of constitutive equations the applied torque load is determined by the change of electrical resistance. The creep of the glue and the foil material, together with the temperature and humidity dependence, may become an obstacle for some applications Kapralov and Fesenko(1984. Thus, there have been optical and magnetical, as well as capacitive sensors introduced . This paper discusses the general idea behind an electrostatic capacitive sensor based on a simple draft of an exemplary measurement setup. For better understanding an own electrostatical, geometrical and mechanical model of this setup has been developed.

  4. Electrostatic sensor modeling for torque measurements

    Science.gov (United States)

    Mika, Michał; Dannert, Mirjam; Mett, Felix; Weber, Harry; Mathis, Wolfgang; Nackenhorst, Udo

    2017-09-01

    Torque load measurements play an important part in various engineering applications, as for automotive industry, in which the drive torque of a motor has to be determined. A widely used measuring method are strain gauges. A thin flexible foil, which supports a metallic pattern, is glued to the surface of the object the torque is being applied to. In case of a deformation due to the torque load, the change in the electrical resistance is measured. With the combination of constitutive equations the applied torque load is determined by the change of electrical resistance. The creep of the glue and the foil material, together with the temperature and humidity dependence, may become an obstacle for some applications Kapralov and Fesenko (1984). Thus, there have been optical and magnetical, as well as capacitive sensors introduced). This paper discusses the general idea behind an electrostatic capacitive sensor based on a simple draft of an exemplary measurement setup. For better understanding an own electrostatical, geometrical and mechanical model of this setup has been developed.

  5. Model measurements for the switched power linac

    International Nuclear Information System (INIS)

    Aronson, S.; Caspers, F.; Haseroth, H.; Knott, J.; Willis, W.

    1987-01-01

    To study some aspects of the structure of the switched power linac (or wakefield transformer), a scaled-up model with 2.4 m diameter has been built. Measurements were performed with real-time and synthetic pulses with spectral components up to 5 GHz. Results are obtained for the achievable transformer ratio as a function of the spectral composition of the pulses and for the influence of discrete feeding at the circumference of the transformer disk. The effects of asymmetric feeding in space and time were also investigated experimentally as well as the influence of the central geometry

  6. Information as a Measure of Model Skill

    Science.gov (United States)

    Roulston, M. S.; Smith, L. A.

    2002-12-01

    Physicist Paul Davies has suggested that rather than the quest for laws that approximate ever more closely to "truth", science should be regarded as the quest for compressibility. The goodness of a model can be judged by the degree to which it allows us to compress data describing the real world. The "logarithmic scoring rule" is a method for evaluating probabilistic predictions of reality that turns this philosophical position into a practical means of model evaluation. This scoring rule measures the information deficit or "ignorance" of someone in possession of the prediction. A more applied viewpoint is that the goodness of a model is determined by its value to a user who must make decisions based upon its predictions. Any form of decision making under uncertainty can be reduced to a gambling scenario. Kelly showed that the value of a probabilistic prediction to a gambler pursuing the maximum return on their bets depends on their "ignorance", as determined from the logarithmic scoring rule, thus demonstrating a one-to-one correspondence between data compression and gambling returns. Thus information theory provides a way to think about model evaluation, that is both philosophically satisfying and practically oriented. P.C.W. Davies, in "Complexity, Entropy and the Physics of Information", Proceedings of the Santa Fe Institute, Addison-Wesley 1990 J. Kelly, Bell Sys. Tech. Journal, 35, 916-926, 1956.

  7. Flavor release measurement from gum model system.

    Science.gov (United States)

    Ovejero-López, Isabel; Haahr, Anne-Mette; van den Berg, Frans; Bredie, Wender L P

    2004-12-29

    Flavor release from a mint-flavored chewing gum model system was measured by atmospheric pressure chemical ionization mass spectroscopy (APCI-MS) and sensory time-intensity (TI). A data analysis method for handling the individual curves from both methods is presented. The APCI-MS data are ratio-scaled using the signal from acetone in the breath of subjects. Next, APCI-MS and sensory TI curves are smoothed by low-pass filtering. Principal component analysis of the individual curves is used to display graphically the product differentiation by APCI-MS or TI signals. It is shown that differences in gum composition can be measured by both instrumental and sensory techniques, providing comparable information. The peppermint oil level (0.5-2% w/w) in the gum influenced both the retronasal concentration and the perceived peppermint flavor. The sweeteners' (sorbitol or xylitol) effect is less apparent. Sensory adaptation and sensitivity differences of human perception versus APCI-MS detection might explain the divergence between the two dynamic measurement methods.

  8. RhinAsthma patient perspective: A Rasch validation study.

    Science.gov (United States)

    Molinengo, Giorgia; Baiardini, Ilaria; Braido, Fulvio; Loera, Barbara

    2018-02-01

    In daily practice, Health-Related Quality of Life (HRQoL) tools are useful for supplementing clinical data with the patient's perspective. To encourage their use by clinicians, the availability of tools that can quickly provide valid results is crucial. A new HRQoL tool has been proposed for patients with asthma and rhinitis: the RhinAsthma Patient Perspective-RAPP. The aim of this study was to evaluate the psychometric robustness of the RAPP using the Item Response Theory (IRT) approach, to evaluate the scalability of items and test whether or not patients use the items response scale correctly. 155 patients (53.5% women, mean age 39.1, range 16-76) were recruited during a multicenter study. RAPP metric properties were investigated using IRT models. Differential item functioning (DIF) was used for gender, age, and asthma control test (ACT). The RAPP adequately fitted the Rating Scale model, demonstrating the equality of the rating scale structure for all items. All statistics on items were satisfactory. The RAPP had adequate internal reliability and showed good ability to discriminate among different groups of participants. DIF analysis indicated that there were no differential item functioning issues for gender. One item showed a DIF by age and four items by ACT. The psychometric evaluation performed using IRT models demonstrated that the RAPP met all the criteria to be considered a reliable and valid method of measurement. From a clinical perspective, this will allow physicians to confidently interpret scores as good indicators of Quality of Life of patients with asthma.

  9. 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

  10. Development and preliminary validation of the EASE: a tool to measure perceived singing voice function.

    Science.gov (United States)

    Phyland, Debra J; Pallant, Julie F; Benninger, Michael S; Thibeault, Susan L; Greenwood, Ken M; Smith, Julian A; Vallance, Neil

    2013-07-01

    Most voice self-rating tools are disease-specific measures and are not suitable for use with healthy voice users. There is a need for a tool that is sensitive to the subtleties of a singer's voice and to perceived physical changes in the singing voice mechanism as a function of load. The aim of this study was to devise and validate a scale to assess singer's perceptions of the current status of their singing voice. Ninety-five vocal health descriptors were collected from focus group interviews of singers. These were reviewed by 25 currently performing music theater (MT) singers. Based on a consensus technique, the number of descriptors was decreased to 42 items. These were administered to a sample of 284 professional MT singers using an online survey to evaluate their perception of current singing voice status. Principal component analysis identified two subsets of items. Rasch analysis was used to evaluate and refine these sets of items to form two 10-item subscales. Both subscales demonstrated good overall fit to the Rasch model, no differential item functioning by sex or age, and good internal consistency reliability. The two subscales were strongly correlated and subsequent Rasch analysis supported their combination to form a single 20-item scale with good psychometric properties. The Evaluation of the Ability to Sing Easily (EASE) is a concise clinical tool to assess singer's perceptions of the current status of their singing voice with good measurement properties. EASE may prove a useful tool to measure changes in the singing voice as indicators of the effect of vocal load. Furthermore, it may offer a valuable means for the prediction or screening of singers "at risk" of developing voice disorders. Copyright © 2013 The Voice Foundation. All rights reserved.

  11. Psychometric evaluation of Persian Nomophobia Questionnaire: Differential item functioning and measurement invariance across gender.

    Science.gov (United States)

    Lin, Chung-Ying; Griffiths, Mark D; Pakpour, Amir H

    2018-03-01

    Background and aims Research examining problematic mobile phone use has increased markedly over the past 5 years and has been related to "no mobile phone phobia" (so-called nomophobia). The 20-item Nomophobia Questionnaire (NMP-Q) is the only instrument that assesses nomophobia with an underlying theoretical structure and robust psychometric testing. This study aimed to confirm the construct validity of the Persian NMP-Q using Rasch and confirmatory factor analysis (CFA) models. Methods After ensuring the linguistic validity, Rasch models were used to examine the unidimensionality of each Persian NMP-Q factor among 3,216 Iranian adolescents and CFAs were used to confirm its four-factor structure. Differential item functioning (DIF) and multigroup CFA were used to examine whether males and females interpreted the NMP-Q similarly, including item content and NMP-Q structure. Results Each factor was unidimensional according to the Rach findings, and the four-factor structure was supported by CFA. Two items did not quite fit the Rasch models (Item 14: "I would be nervous because I could not know if someone had tried to get a hold of me;" Item 9: "If I could not check my smartphone for a while, I would feel a desire to check it"). No DIF items were found across gender and measurement invariance was supported in multigroup CFA across gender. Conclusions Due to the satisfactory psychometric properties, it is concluded that the Persian NMP-Q can be used to assess nomophobia among adolescents. Moreover, NMP-Q users may compare its scores between genders in the knowledge that there are no score differences contributed by different understandings of NMP-Q items.

  12. 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.

  13. Measurement and modelling in anthropo-radiometry

    International Nuclear Information System (INIS)

    Carlan, Loic de

    2011-01-01

    In this HDR (Accreditation to supervise researches) report, the author gives an overview of his research activities, gives a summary of his research thesis (feasibility study of an actinide measurement system in the case of lungs), and proposes a research report on the different aspects of anthropo-radiometric measurement: context (principles, significance, sampling phantoms), development of digital phantoms (software presentation and validation), interface development and validation, application to actinide measurement in lung, taking biokinetic data into account for anthropo-radiometric measurement

  14. Psychometric assessment of the patient activation measure short form (PAM-13) in rural settings.

    Science.gov (United States)

    Hung, Man; Carter, Marjorie; Hayden, Candace; Dzierzon, Rhonda; Morales, Jose; Snow, Laverne; Butler, Jorie; Bateman, Kim; Samore, Matthew

    2013-04-01

    The patient activation measure short form (PAM-13) assesses patients' self-reported health management skills, knowledge, confidence, and motivation. We used item response theory to evaluate the psychometric properties of the PAM-13 utilized in rural settings. A Rasch partial credit model analysis was conducted on the PAM-13 instrument using a sample of 812 rural patients recruited by providers and our research staff. Specially, we examined dimensionality, item fit, and quality of measures, category response curves, and item differential functioning. Convergent and divergent validities were also examined. The PAM-13 instrument has excellent convergent and divergent validities. It is fairly unidimensional, and all items fit the Rasch model well. It has relatively high person and item reliability indices. Majority of the items were free of item differential functioning. There were, however, some issues with ceiling effects. Additionally, there was a lack of responses for category one across all items. Patient activation measure short form (PAM-13) performs well in some areas, but not all. In general, more items need to be added to cover the upper end of the trait. The four response categories of PAM-13 should be collapsed into three.

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

    Science.gov (United States)

    Hwang, Ai-Wen; Chou, Yeh-Tai; Hsieh, Ching-Lin; Hsieh, Wu-Shiun; Liao, Hua-Fang; Wong, Alice May-Kuen

    2015-01-01

    Using multidomain developmental screening tools is a feasible method for pediatric health care professionals to identify children at risk of developmental problems in multiple domains simultaneously. The purpose of this study was to develop a Rasch-based tool for Multidimensional Screening in Child Development (MuSiC) for children aged 0-3 years. The MuSic was developed by constructing items bank based on three commonly used screening tools, validating with developmental status (at risk for delay or not) on five developmental domains. Parents of a convenient sample of 632 children (aged 3-35.5 months) with and without developmental delays responded to items from the three screening tools funded by health authorities in Taiwan. Item bank was determined by item fit of Rasch analysis for each of the five developmental domains (cognitive skills, language skills, gross motor skills, fine motor skills, and socioadaptive skills). Children's performance scores in logits derived in Rasch analysis were validated with developmental status for each domain using the area under receiver operating characteristic curves. MuSiC, a 75-item developmental screening tool for five domains, was derived. The diagnostic validity of all five domains was acceptable for all stages of development, except for the infant stage (≤11 months and 15 days). 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. Copyright © 2014. Published by Elsevier B.V.

  16. Combining GPS measurements and IRI model predictions

    International Nuclear Information System (INIS)

    Hernandez-Pajares, M.; Juan, J.M.; Sanz, J.; Bilitza, D.

    2002-01-01

    The free electrons distributed in the ionosphere (between one hundred and thousands of km in height) produce a frequency-dependent effect on Global Positioning System (GPS) signals: a delay in the pseudo-orange and an advance in the carrier phase. These effects are proportional to the columnar electron density between the satellite and receiver, i.e. the integrated electron density along the ray path. Global ionospheric TEC (total electron content) maps can be obtained with GPS data from a network of ground IGS (international GPS service) reference stations with an accuracy of few TEC units. The comparison with the TOPEX TEC, mainly measured over the oceans far from the IGS stations, shows a mean bias and standard deviation of about 2 and 5 TECUs respectively. The discrepancies between the STEC predictions and the observed values show an RMS typically below 5 TECUs (which also includes the alignment code noise). he existence of a growing database 2-hourly global TEC maps and with resolution of 5x2.5 degrees in longitude and latitude can be used to improve the IRI prediction capability of the TEC. When the IRI predictions and the GPS estimations are compared for a three month period around the Solar Maximum, they are in good agreement for middle latitudes. An over-determination of IRI TEC has been found at the extreme latitudes, the IRI predictions being, typically two times higher than the GPS estimations. Finally, local fits of the IRI model can be done by tuning the SSN from STEC GPS observations

  17. Generally objective measurement of human temperature and reading ability: some corollaries.

    Science.gov (United States)

    Stenner, A Jackson; Stone, Mark

    2010-01-01

    We argue that a goal of measurement is general objectivity: point estimates of a person's measure (height, temperature, and reader ability) should be independent of the instrument and independent of the sample in which the person happens to find herself. In contrast, Rasch's concept of specific objectivity requires only differences (i.e., comparisons) between person measures to be independent of the instrument. We present a canonical case in which there is no overlap between instruments and persons: each person is measured by a unique instrument. We then show what is required to estimate measures in this degenerate case. The canonical case encourages a simplification and reconceptualization of validity and reliability. Not surprisingly, this reconceptualization looks a lot like the way physicists and chemometricians think about validity and measurement error. We animate this presentation with a technology that blurs the distinction between instruction, assessment, and generally objective measurement of reader ability. We encourage adaptation of this model to health outcomes measurement.

  18. 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

    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...... clinical characteristics (such as age, gender, pain intensity, pain duration and care setting), depending on the country. CONCLUSION: As similar results have been found for the RMDQ-24, we believe it is timely to reconsider whether: (i) the RMDQ should be reconstructed using an item-response theory...

  19. Measuring similarity between business process models

    NARCIS (Netherlands)

    Dongen, van B.F.; Dijkman, R.M.; Mendling, J.

    2007-01-01

    Quality aspects become increasingly important when business process modeling is used in a large-scale enterprise setting. In order to facilitate a storage without redundancy and an efficient retrieval of relevant process models in model databases it is required to develop a theoretical understanding

  20. The emperor’s new measurement model

    NARCIS (Netherlands)

    Zand Scholten, A.; Maris, G.; Borsboom, D.

    2011-01-01

    In this article the author discusses professor Stephen M. Humphry's critical attitude with respect to psychometric modeling. The author criticizes Humphry's model stating that the model is theoretically interesting but cannot be tested as it is not identified. The author also states that Humphry's

  1. Compressor Part I: Measurement and Design Modeling

    Directory of Open Access Journals (Sweden)

    Thomas W. Bein

    1999-01-01

    method used to design the 125-ton compressor is first reviewed and some related performance curves are predicted based on a quasi-3D method. In addition to an overall performance measurement, a series of instruments were installed on the compressor to identify where the measured performance differs from the predicted performance. The measurement techniques for providing the diagnostic flow parameters are also described briefly. Part II of this paper provides predictions of flow details in the areas of the compressor where there were differences between the measured and predicted performance.

  2. Radiation budget measurement/model interface research

    Science.gov (United States)

    Vonderhaar, T. H.

    1981-01-01

    The NIMBUS 6 data were analyzed to form an up to date climatology of the Earth radiation budget as a basis for numerical model definition studies. Global maps depicting infrared emitted flux, net flux and albedo from processed NIMBUS 6 data for July, 1977, are presented. Zonal averages of net radiation flux for April, May, and June and zonal mean emitted flux and net flux for the December to January period are also presented. The development of two models is reported. The first is a statistical dynamical model with vertical and horizontal resolution. The second model is a two level global linear balance model. The results of time integration of the model up to 120 days, to simulate the January circulation, are discussed. Average zonal wind, meridonal wind component, vertical velocity, and moisture budget are among the parameters addressed.

  3. Measuring Change with the Rating Scale Model.

    Science.gov (United States)

    Ludlow, Larry H.; And Others

    The Rehabilitation Research and Development Laboratory at the United States Veterans Administration Hines Hospital is engaged in a long-term evaluation of blind rehabilitation. One aspect of the evaluation project focuses on the measurement of attitudes toward blindness. Our aim is to measure changes in attitudes toward blindness from…

  4. Migration Flows: Measurement, Analysis and Modeling

    NARCIS (Netherlands)

    Willekens, F.J.; White, Michael J.

    2016-01-01

    This chapter is an introduction to the study of migration flows. It starts with a review of major definition and measurement issues. Comparative studies of migration are particularly difficult because different countries define migration differently and measurement methods are not harmonized.

  5. Modeling and estimation of measurement errors

    International Nuclear Information System (INIS)

    Neuilly, M.

    1998-01-01

    Any person in charge of taking measures is aware of the inaccuracy of the results however cautiously he may handle. Sensibility, accuracy, reproducibility define the significance of a result. The use of statistical methods is one of the important tools to improve the quality of measurement. The accuracy due to these methods revealed the little difference in the isotopic composition of uranium ore which led to the discovery of Oklo fossil reactor. This book is dedicated to scientists and engineers interested in measurement whatever their investigation interests are. Experimental results are presented as random variables and their laws of probability are approximated by normal law, Poison law or Pearson distribution. The impact of 1 or more parameters on the total error can be evaluated by drawing factorial plans and by using variance analysis methods. This method is also used in intercomparison procedures between laboratories and to detect any abnormal shift in a series of measurement. (A.C.)

  6. 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.

  7. Optimal parametric modelling of measured short waves

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.

    the importance of selecting a suitable sampling interval for better estimates of parametric modelling and also for better statistical representation. Implementation of the above algorithms in a structural monitoring system has the potential advantage of storing...

  8. Modelling methods for milk intake measurements

    International Nuclear Information System (INIS)

    Coward, W.A.

    1999-01-01

    One component of the first Research Coordination Programme was a tutorial session on modelling in in-vivo tracer kinetic methods. This section describes the principles that are involved and how these can be translated into spreadsheets using Microsoft Excel and the SOLVER function to fit the model to the data. The purpose of this section is to describe the system developed within the RCM, and how it is used

  9. Measuring and modelling the structure of chocolate

    Science.gov (United States)

    Le Révérend, Benjamin J. D.; Fryer, Peter J.; Smart, Ian; Bakalis, Serafim

    2015-01-01

    The cocoa butter present in chocolate exists as six different polymorphs. To achieve the desired crystal form (βV), traditional chocolate manufacturers use relatively slow cooling (chocolate products during processing as well as the crystal structure of cocoa butter throughout the process. A set of ordinary differential equations describes the kinetics of fat crystallisation. The parameters were obtained by fitting the model to a set of DSC curves. The heat transfer equations were coupled to the kinetic model and solved using commercially available CFD software. A method using single crystal XRD was developed using a novel subtraction method to quantify the cocoa butter structure in chocolate directly and results were compared to the ones predicted from the model. The model was proven to predict phase change temperature during processing accurately (±1°C). Furthermore, it was possible to correctly predict phase changes and polymorphous transitions. The good agreement between the model and experimental data on the model geometry allows a better design and control of industrial processes.

  10. Saving energy in 1-D : tailoring energy-saving advice using a Rasch-based energy recommender system

    NARCIS (Netherlands)

    Starke, Alain; Willemsen, Martijn; Snijders, Chris; Ge, Mouhzi; Ricci, Francesco

    2015-01-01

    Although there are numerous possibilities to save energy, conservation initiatives often do not tailor their content to the consumer. By considering energy conservation as a one-dimensional construct, where different behaviors have different execution difficulties, we have set out a Rasch-based

  11. Measuring Health-related Transportation Barriers in Urban Settings.

    Science.gov (United States)

    Locatelli, Sara M; Sharp, Lisa K; Syed, Saming T; Bhansari, Shikhi; Gerber, Ben S

    Access to reliable transportation is important for people with chronic diseases considering the need for frequent medical visits and for medications from the pharmacy. Understanding of the extent to which transportation barriers, including lack of transportation, contribute to poor health outcomes has been hindered by a lack of consistency in measuring or operationally defining "transportation barriers." The current study uses the Rasch measurement model to examine the psychometric properties of a new measure designed to capture types of transportation and associated barriers within an urban context. Two hundred forty-four adults with type 2 diabetes were recruited from within an academic medical center in Chicago and completed the newly developed transportation questions as part of a larger National Institutes of Health funded study (ClinicalTrials.gov identifier: NCT01498159). Results suggested a two subscale structure that reflected 1) general transportation barriers and 2) public transportation barriers.

  12. 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.

  13. 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.

  14. Exponential GARCH Modeling with Realized Measures of Volatility

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Huang, Zhuo

    returns and volatility. We apply the model to DJIA stocks and an exchange traded fund that tracks the S&P 500 index and find that specifications with multiple realized measures dominate those that rely on a single realized measure. The empirical analysis suggests some convenient simplifications......We introduce the Realized Exponential GARCH model that can utilize multiple realized volatility measures for the modeling of a return series. The model specifies the dynamic properties of both returns and realized measures, and is characterized by a flexible modeling of the dependence between...

  15. Flavor release measurement from gum model system

    DEFF Research Database (Denmark)

    Ovejero-López, I.; Haahr, Anne-Mette; van den Berg, Frans W.J.

    2004-01-01

    composition can be measured by both instrumental and sensory techniques, providing comparable information. The peppermint oil level (0.5-2% w/w) in the gum influenced both the retronasal concentration and the perceived peppermint flavor. The sweeteners' (sorbitol or xylitol) effect is less apparent. Sensory...

  16. Coherent acceptability measures in multiperiod models

    NARCIS (Netherlands)

    Roorda, Berend; Schumacher, Hans; Engwerda, Jacob

    2005-01-01

    The framework of coherent risk measures has been introduced by Artzner et al. (1999; Math. Finance 9, 203–228) in a single-period setting. Here, we investigate a similar framework in a multiperiod context. We add an axiom of dynamic consistency to the standard coherence axioms, and obtain a

  17. Performance Measurement Model A TarBase model with ...

    Indian Academy of Sciences (India)

    rohit

    Model A 8.0 2.0 94.52% 88.46% 76 108 12 12 0.86 0.91 0.78 0.94. Model B 2.0 2.0 93.18% 89.33% 64 95 10 9 0.88 0.90 0.75 0.98. The above results for TEST – 1 show details for our two models (Model A and Model B).Performance of Model A after adding of 32 negative dataset of MiRTif on our testing set(MiRecords) ...

  18. Radiation risk estimation based on measurement error models

    CERN Document Server

    Masiuk, Sergii; Shklyar, Sergiy; Chepurny, Mykola; Likhtarov, Illya

    2017-01-01

    This monograph discusses statistics and risk estimates applied to radiation damage under the presence of measurement errors. The first part covers nonlinear measurement error models, with a particular emphasis on efficiency of regression parameter estimators. In the second part, risk estimation in models with measurement errors is considered. Efficiency of the methods presented is verified using data from radio-epidemiological studies.

  19. Time versus frequency domain measurements: layered model ...

    African Journals Online (AJOL)

    ... their high frequency content while among TEM data sets with low frequency content, the averaging times for the FEM ellipticity were shorter than the TEM quality. Keywords: ellipticity, frequency domain, frequency electromagnetic method, model parameter, orientation error, time domain, transient electromagnetic method

  20. Modelling of power-reactivity coefficient measurement

    International Nuclear Information System (INIS)

    Strmensky, C.; Petenyi, V.; Jagrik, J.; Minarcin, M.; Hascik, R.; Toth, L.

    2005-01-01

    Report describes results of modeling of power-reactivity coefficient analysis on power-level. In paper we calculate values of discrepancies arisen during transient process. These discrepancies can be arisen as result of experiment evaluation and can be caused by disregard of 3D effects on neutron distribution. The results are critically discussed (Authors)

  1. Measuring outcomes in psychiatry: an inpatient model.

    Science.gov (United States)

    Davis, D E; Fong, M L

    1996-02-01

    This article describes a system for measuring outcomes recently implemented in the department of psychiatry of Baptist Memorial Hospital, a 78-bed inpatient and day treatment unit that represents one service line of a large, urban teaching hospital in Memphis. In June 1993 Baptist Hospital began a 15-month pilot test of PsychSentinel, a measurement tool developed by researchers in the Department of Community Medicine at the University of Connecticut. The hospital identified the following four primary goals for this pilot project: provide data for internal hospital program evaluation, provide data for external marketing in a managed care environment, satisfy requirements of the Joint Commission on Accreditation of Health Care Organizations, and generate studies that add to the literature in psychiatry and psychology. PsychSentinel is based on the standardized diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). The outcome measure assesses the change in the number of symptoms of psychopathology that occurs between admission and discharge from the hospital. Included in the nonproprietary system are risk adjustment factors, as well as access to a national reference database for comparative analysis purposes. Data collection can be done by trained ancillary staff members, with as much or as little direct physician involvement as desired. The system has proven to be both time effective and cost effective, and it provides important outcome information both at the program level and at the clinician level. After the pilot test, the staff at Baptist Memorial Hospital determined that the system met all initial objectives identified and recently adopted the system as an ongoing measure of quality patient care in the department of psychiatry.

  2. Measurement Models for Reasoned Action Theory

    OpenAIRE

    Hennessy, Michael; Bleakley, Amy; Fishbein, Martin

    2012-01-01

    Quantitative researchers distinguish between causal and effect indicators. What are the analytic problems when both types of measures are present in a quantitative reasoned action analysis? To answer this question, we use data from a longitudinal study to estimate the association between two constructs central to reasoned action theory: behavioral beliefs and attitudes toward the behavior. The belief items are causal indicators that define a latent variable index while the attitude items are ...

  3. 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

  4. Artificial intelligence model for sustain ability measurement

    International Nuclear Information System (INIS)

    Navickiene, R.; Navickas, K.

    2012-01-01

    The article analyses the main dimensions of organizational sustain ability, their possible integrations into artificial neural network. In this article authors performing analyses of organizational internal and external environments, their possible correlations with 4 components of sustain ability, and the principal determination models for sustain ability of organizations. Based on the general principles of sustainable development organizations, a artificial intelligence model for the determination of organizational sustain ability has been developed. The use of self-organizing neural networks allows the identification of the organizational sustain ability and the endeavour to explore vital, social, antropogenical and economical efficiency. The determination of the forest enterprise sustain ability is expected to help better manage the sustain ability. (Authors)

  5. Measuring Quality Satisfaction with Servqual Model

    Directory of Open Access Journals (Sweden)

    Dan Păuna

    2012-05-01

    Full Text Available The orientation to customer satisfaction is not a recent phenomenon, many very successfulbusinesspeople from the beginning of the 20th century, such as Sir Henry Royce, a name synonymous withRoll – Royce vehicles, stated the first principle regarding customer satisfaction “Our interest in the Roll-Royce cars does not end at the moment when the owner pays for and takes delivery the car. Our interest in thecar never wanes. Our ambition is that every purchaser of the Rolls - Royce car shall continue to be more thansatisfied (Rolls-Royce.” The following paper tries to deal with the important qualities of the concept for themeasuring of the gap between expected costumer services satisfactions, and perceived services like a routinecustomer feedback process, by means of a relatively new model, the Servqual model.

  6. Validation of the measurement model concept for error structure identification

    International Nuclear Information System (INIS)

    Shukla, Pavan K.; Orazem, Mark E.; Crisalle, Oscar D.

    2004-01-01

    The development of different forms of measurement models for impedance has allowed examination of key assumptions on which the use of such models to assess error structure are based. The stochastic error structures obtained using the transfer-function and Voigt measurement models were identical, even when non-stationary phenomena caused some of the data to be inconsistent with the Kramers-Kronig relations. The suitability of the measurement model for assessment of consistency with the Kramers-Kronig relations, however, was found to be more sensitive to the confidence interval for the parameter estimates than to the number of parameters in the model. A tighter confidence interval was obtained for Voigt measurement model, which made the Voigt measurement model a more sensitive tool for identification of inconsistencies with the Kramers-Kronig relations

  7. Multivariate linear models and repeated measurements revisited

    DEFF Research Database (Denmark)

    Dalgaard, Peter

    2009-01-01

    Methods for generalized analysis of variance based on multivariate normal theory have been known for many years. In a repeated measurements context, it is most often of interest to consider transformed responses, typically within-subject contrasts or averages. Efficiency considerations leads...... to sphericity assumptions, use of F tests and the Greenhouse-Geisser and Huynh-Feldt adjustments to compensate for deviations from sphericity. During a recent implementation of such methods in the R language, the general structure of such transformations was reconsidered, leading to a flexible specification...

  8. Statistical learning modeling method for space debris photometric measurement

    Science.gov (United States)

    Sun, Wenjing; Sun, Jinqiu; Zhang, Yanning; Li, Haisen

    2016-03-01

    Photometric measurement is an important way to identify the space debris, but the present methods of photometric measurement have many constraints on star image and need complex image processing. Aiming at the problems, a statistical learning modeling method for space debris photometric measurement is proposed based on the global consistency of the star image, and the statistical information of star images is used to eliminate the measurement noises. First, the known stars on the star image are divided into training stars and testing stars. Then, the training stars are selected as the least squares fitting parameters to construct the photometric measurement model, and the testing stars are used to calculate the measurement accuracy of the photometric measurement model. Experimental results show that, the accuracy of the proposed photometric measurement model is about 0.1 magnitudes.

  9. Another Look at the PART-O Using the Traumatic Brain Injury Model Systems National Database: Scoring to Optimize Psychometrics.

    Science.gov (United States)

    Malec, James F; Whiteneck, Gale G; Bogner, Jennifer A

    2016-02-01

    To integrate previous approaches to scoring the Participation Assessment with Recombined Tools-Objective (PART-O) in a unidimensional scale. Retrospective analysis of PART-O data from the Traumatic Brain Injury Model Systems. Community. Data from individuals (N=469) selected randomly from participants who completed 1-year follow-up in the Traumatic Brain Injury Model Systems were used in Rasch model development. The model was subsequently tested on data from additional random samples of similar size at 1-, 2-, 5-, 10-, and >15-year follow-ups. Not applicable. PART-O. After combining items for productivity and social interaction, the initial analysis at 1-year follow-up indicated relatively good fit to the Rasch model (person reliability=.80) but also suggested item misfit and that the 0-to-5 scale used for most items did not consistently show clear separation between rating levels. Reducing item rating scales to 3 levels (except combined and dichotomous items) resolved these issues and demonstrated good item level discrimination, fit, and person reliability (.81), with no evidence of multidimensionality. These results replicated in analyses at each additional follow-up period. Modifications to item scoring for the PART-O resulted in a unidimensional parametric equivalent measure that addresses previous concerns about competing item relations, and it fit the Rasch model consistently across follow-up periods. The person-item map shows a progression toward greater community participation from solitary and dyadic activities, such as leaving the house and having a friend through social and productivity activities, to group activities with others who share interests or beliefs. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  10. 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.

  11. Empirical Comparison of Criterion Referenced Measurement Models

    Science.gov (United States)

    1976-10-01

    rument cons isting of a l a r~c nu mb r of items. The models ~o·ould the n be used to es t imate the tna.• s t""~r c us in~ a smaller and mor r ea lis...ti number o f items. This. rrrun·h is em- piri ca l a nd more dir\\’c tly o ri e nted to pr ti ca l app li ·a i on:; \\ viH ’ r t. tes ting time a nd the

  12. Measuring productivity differences in equilibrium search models

    DEFF Research Database (Denmark)

    Lanot, Gauthier; Neumann, George R.

    1996-01-01

    Equilibrium search models require unobserved heterogeneity in productivity to fit observed wage distribution data, but provide no guidance about the location parameter of the heterogeneity. In this paper we show that the location of the productivity heterogeneity implies a mode in a kernel density...... estimate of the wage distribution. The number of such modes and their location are identified using bump hunting techniques due to Silverman (1981). These techniques are applied to Danish panel data on workers and firms. These estimates are used to assess the importance of employer wage policy....

  13. 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.

  14. Measurement Models for Reasoned Action Theory.

    Science.gov (United States)

    Hennessy, Michael; Bleakley, Amy; Fishbein, Martin

    2012-03-01

    Quantitative researchers distinguish between causal and effect indicators. What are the analytic problems when both types of measures are present in a quantitative reasoned action analysis? To answer this question, we use data from a longitudinal study to estimate the association between two constructs central to reasoned action theory: behavioral beliefs and attitudes toward the behavior. The belief items are causal indicators that define a latent variable index while the attitude items are effect indicators that reflect the operation of a latent variable scale. We identify the issues when effect and causal indicators are present in a single analysis and conclude that both types of indicators can be incorporated in the analysis of data based on the reasoned action approach.

  15. Transport services quality measurment using SERVQUAL model

    Directory of Open Access Journals (Sweden)

    Maksimović Mlađan V.

    2017-01-01

    Full Text Available Quality in the world is considered to be the most important phenomenon of our age, with a permanent and irreversible growing trend of its emphasis. Many companies have come to the conclusion that high quality of services can provide them with a potential competitive advantage, leading to superior sales results and profit making. The aim of this paper is to test the applicability of service SERVQUAL dimensions and measure the quality of services in the public transport of passengers. Based on the data obtained by researching the views of public transport users in Kragujevac using the SERVQUAL methodology and statistical analysis based on defined service quality dimensions, this research will show the level of quality of urban transport services in Kragujevac and based on this, make recommendations for improving the quality of service.

  16. Laser alignment measurement model with double beam

    Science.gov (United States)

    Mo, Changtao; Zhang, Lili; Hou, Xianglin; Wang, Ming; Lv, Jia; Du, Xin; He, Ping

    2012-10-01

    Double LD-Double PSD schedule.employ a symmetric structure and there are a laser and a PSD receiver on each axis. The Double LD-Double PSD is used, and the rectangular coordinate system is set up by use of the relationship of arbitrary two points coordinates, and then the parameter formula is deduced by the knowledge of solid geometry. Using the data acquisition system and the data processing model of laser alignment meter with double laser beam and two detector , basing on the installation parameter of the computer, we can have the state parameter between the two shafts by more complicated calculation and correction. The correcting data of the four under chassis of the adjusted apparatus moving on the level and the vertical plane can be calculated using the computer. This will instruct us to move the apparatus to align the shafts.

  17. Scale Model Thruster Acoustic Measurement Results

    Science.gov (United States)

    Vargas, Magda; Kenny, R. Jeremy

    2013-01-01

    The Space Launch System (SLS) Scale Model Acoustic Test (SMAT) is a 5% scale representation of the SLS vehicle, mobile launcher, tower, and launch pad trench. The SLS launch propulsion system will be comprised of the Rocket Assisted Take-Off (RATO) motors representing the solid boosters and 4 Gas Hydrogen (GH2) thrusters representing the core engines. The GH2 thrusters were tested in a horizontal configuration in order to characterize their performance. In Phase 1, a single thruster was fired to determine the engine performance parameters necessary for scaling a single engine. A cluster configuration, consisting of the 4 thrusters, was tested in Phase 2 to integrate the system and determine their combined performance. Acoustic and overpressure data was collected during both test phases in order to characterize the system's acoustic performance. The results from the single thruster and 4- thuster system are discussed and compared.

  18. Measuring and Modeling Shared Visual Attention

    Science.gov (United States)

    Mulligan, Jeffrey B.; Gontar, Patrick

    2016-01-01

    Multi-person teams are sometimes responsible for critical tasks, such as flying an airliner. Here we present a method using gaze tracking data to assess shared visual attention, a term we use to describe the situation where team members are attending to a common set of elements in the environment. Gaze data are quantized with respect to a set of N areas of interest (AOIs); these are then used to construct a time series of N dimensional vectors, with each vector component representing one of the AOIs, all set to 0 except for the component corresponding to the currently fixated AOI, which is set to 1. The resulting sequence of vectors can be averaged in time, with the result that each vector component represents the proportion of time that the corresponding AOI was fixated within the given time interval. We present two methods for comparing sequences of this sort, one based on computing the time-varying correlation of the averaged vectors, and another based on a chi-square test testing the hypothesis that the observed gaze proportions are drawn from identical probability distributions. We have evaluated the method using synthetic data sets, in which the behavior was modeled as a series of "activities," each of which was modeled as a first-order Markov process. By tabulating distributions for pairs of identical and disparate activities, we are able to perform a receiver operating characteristic (ROC) analysis, allowing us to choose appropriate criteria and estimate error rates. We have applied the methods to data from airline crews, collected in a high-fidelity flight simulator (Haslbeck, Gontar & Schubert, 2014). We conclude by considering the problem of automatic (blind) discovery of activities, using methods developed for text analysis.

  19. Measurement of Function Post Hip Fracture: Testing a Comprehensive Measurement Model of Physical Function.

    Science.gov (United States)

    Resnick, Barbara; Gruber-Baldini, Ann L; Hicks, Gregory; Ostir, Glen; Klinedinst, N Jennifer; Orwig, Denise; Magaziner, Jay

    2016-07-01

    Measurement of physical function post hip fracture has been conceptualized using multiple different measures. This study tested a comprehensive measurement model of physical function. This was a descriptive secondary data analysis including 168 men and 171 women post hip fracture. Using structural equation modeling, a measurement model of physical function which included grip strength, activities of daily living, instrumental activities of daily living, and performance was tested for fit at 2 and 12 months post hip fracture, and among male and female participants. Validity of the measurement model of physical function was evaluated based on how well the model explained physical activity, exercise, and social activities post hip fracture. The measurement model of physical function fit the data. The amount of variance the model or individual factors of the model explained varied depending on the activity. Decisions about the ideal way in which to measure physical function should be based on outcomes considered and participants. The measurement model of physical function is a reliable and valid method to comprehensively measure physical function across the hip fracture recovery trajectory. © 2015 Association of Rehabilitation Nurses.

  20. Evaluating measurement of dynamic constructs: defining a measurement model of derivatives.

    Science.gov (United States)

    Estabrook, Ryne

    2015-03-01

    While measurement evaluation has been embraced as an important step in psychological research, evaluating measurement structures with longitudinal data is fraught with limitations. This article defines and tests a measurement model of derivatives (MMOD), which is designed to assess the measurement structure of latent constructs both for analyses of between-person differences and for the analysis of change. Simulation results indicate that MMOD outperforms existing models for multivariate analysis and provides equivalent fit to data generation models. Additional simulations show MMOD capable of detecting differences in between-person and within-person factor structures. Model features, applications, and future directions are discussed. (c) 2015 APA, all rights reserved).

  1. Modeling returns volatility: Realized GARCH incorporating realized risk measure

    Science.gov (United States)

    Jiang, Wei; Ruan, Qingsong; Li, Jianfeng; Li, Ye

    2018-06-01

    This study applies realized GARCH models by introducing several risk measures of intraday returns into the measurement equation, to model the daily volatility of E-mini S&P 500 index futures returns. Besides using the conventional realized measures, realized volatility and realized kernel as our benchmarks, we also use generalized realized risk measures, realized absolute deviation, and two realized tail risk measures, realized value-at-risk and realized expected shortfall. The empirical results show that realized GARCH models using the generalized realized risk measures provide better volatility estimation for the in-sample and substantial improvement in volatility forecasting for the out-of-sample. In particular, the realized expected shortfall performs best for all of the alternative realized measures. Our empirical results reveal that future volatility may be more attributable to present losses (risk measures). The results are robust to different sample estimation windows.

  2. 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.

  3. 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

  4. Using LISREL to Evaluate Measurement Models and Scale Reliability.

    Science.gov (United States)

    Fleishman, John; Benson, Jeri

    1987-01-01

    LISREL program was used to examine measurement model assumptions and to assess reliability of Coopersmith Self-Esteem Inventory for Children, Form B. Data on 722 third-sixth graders from over 70 schools in large urban school district were used. LISREL program assessed (1) nature of basic measurement model for scale, (2) scale invariance across…

  5. Integration of Error Compensation of Coordinate Measuring Machines into Feature Measurement: Part I—Model Development

    Science.gov (United States)

    Calvo, Roque; D’Amato, Roberto; Gómez, Emilio; Domingo, Rosario

    2016-01-01

    The development of an error compensation model for coordinate measuring machines (CMMs) and its integration into feature measurement is presented. CMMs are widespread and dependable instruments in industry and laboratories for dimensional measurement. From the tip probe sensor to the machine display, there is a complex transformation of probed point coordinates through the geometrical feature model that makes the assessment of accuracy and uncertainty measurement results difficult. Therefore, error compensation is not standardized, conversely to other simpler instruments. Detailed coordinate error compensation models are generally based on CMM as a rigid-body and it requires a detailed mapping of the CMM’s behavior. In this paper a new model type of error compensation is proposed. It evaluates the error from the vectorial composition of length error by axis and its integration into the geometrical measurement model. The non-explained variability by the model is incorporated into the uncertainty budget. Model parameters are analyzed and linked to the geometrical errors and uncertainty of CMM response. Next, the outstanding measurement models of flatness, angle, and roundness are developed. The proposed models are useful for measurement improvement with easy integration into CMM signal processing, in particular in industrial environments where built-in solutions are sought. A battery of implementation tests are presented in Part II, where the experimental endorsement of the model is included. PMID:27690052

  6. Integration of Error Compensation of Coordinate Measuring Machines into Feature Measurement: Part I—Model Development

    Directory of Open Access Journals (Sweden)

    Roque Calvo

    2016-09-01

    Full Text Available The development of an error compensation model for coordinate measuring machines (CMMs and its integration into feature measurement is presented. CMMs are widespread and dependable instruments in industry and laboratories for dimensional measurement. From the tip probe sensor to the machine display, there is a complex transformation of probed point coordinates through the geometrical feature model that makes the assessment of accuracy and uncertainty measurement results difficult. Therefore, error compensation is not standardized, conversely to other simpler instruments. Detailed coordinate error compensation models are generally based on CMM as a rigid-body and it requires a detailed mapping of the CMM’s behavior. In this paper a new model type of error compensation is proposed. It evaluates the error from the vectorial composition of length error by axis and its integration into the geometrical measurement model. The non-explained variability by the model is incorporated into the uncertainty budget. Model parameters are analyzed and linked to the geometrical errors and uncertainty of CMM response. Next, the outstanding measurement models of flatness, angle, and roundness are developed. The proposed models are useful for measurement improvement with easy integration into CMM signal processing, in particular in industrial environments where built-in solutions are sought. A battery of implementation tests are presented in Part II, where the experimental endorsement of the model is included.

  7. Development of Patient-reported Outcomes Measure of Pharmaceutical Therapy for Quality of Life (PROMPT-QoL): A novel instrument for medication management.

    Science.gov (United States)

    Sakthong, Phantipa; Suksanga, Phattrapa; Sakulbumrungsil, Rungpetch; Winit-Watjana, Win

    2015-01-01

    Medicines can affect a patient's health-related quality of life (HRQoL), but there exists no standardized HRQoL measure for medication management. To develop the new HRQoL instrument "Patient-reported Outcomes Measure of Pharmaceutical Therapy for Quality of Life" (PROMPT-QoL), and to evaluate its content validity and preliminary psychometrics using a Rasch model. The PROMPT-QoL questionnaire was developed through the concept review, item generation, cognitive interviews, and initial psychometric evaluation. Its first draft was initially tested by Round-1 interviews of 120 adult outpatients taking their medicines at least three months continuously. The final draft with 43 items was then constructed and checked by 10 physicians and 5 pharmacists for the questionnaire importance and content validity. Round-2 interviews in six patient groups with 10 patients of each were conducted to elicit patients' understanding of the questionnaire and assess preliminary psychometrics using the Rasch analysis, including fit statistics, person and item reliabilities. The 43-item PROMPT-QoL comprised 10 domains: General Attitude toward Medication Use, Medicine Information, Disease Information, Medicine Effectiveness, Impacts of Medicines and Side-effects, Psychological Impacts of Medication Use, Convenience, Availability and Accessibility, Therapeutic Relationship with Healthcare Providers, and Overall QoL. Based on the patient interviews and expert review, the questionnaire was considered important, useful, and comprehensive. All items and domains yielded content validity indexes above the acceptable values of 0.80 and 0.90, respectively. In Round 2, thirty-nine problems identified in Group 1 were reduced to two issues in Group 6 after amendments. The Rasch analysis revealed eight items were misfit and two domains were reliable for both personal and item aspects (Medicine Information and Psychological Impacts of Medication Use). The newly developed PROMPT-QoL has favorable content

  8. Factors Influencing Singapore Students' Choice of Physics as a Tertiary Field of Study: A Rasch analysis

    Science.gov (United States)

    Oon, Pey-Tee; Subramaniam, R.

    2013-01-01

    Asian students often perform well in international science and mathematics assessments. Their attitude toward technical subjects, such as physics, remains curious for many. The present study examines Singapore school students' views on various aspects of physics according to whether they intend to choose physics as an advanced field of study. A sample of 1076 physics students, from 16 secondary schools and junior colleges, participated in this study. The students were categorized as physics choosers or non-choosers according to their indicated intention, as sought in the survey, to study or not to study physics as a major subject at university after their leaving level examinations. Rasch-anchored analysis was employed to interpret the results; the use of Rasch analysis has helped to overcome significantly the psychometric limitations inherent in the treatment of Likert scale type of data using traditional analysis. As expected, the image of physics as a difficult subject surfaced in the samples used in our study. The students recognized unequivocally the utilitarian value of physics: physics is said to enhance career options and is necessary for technological progress to occur in a country. They also showed high interest in school physics-this is so even for students who are not keen to study physics in the future, a finding which is at variance with other studies reported from Western countries. School physics is seen to be relevant, and physics teachers are viewed as being able to foster students' interest in physics. Laboratory work, enrichment activities, and physics textbooks were reported to be important in order to encourage students to like physics. Though the physics choosers showed greater intention in physics, they were generally not inclined to pursue physics-related careers after graduation. Parents and peers at school, on the other hand, are perceived to display unenthusiastic attitudes toward physics. Possible reasons for these are discussed along

  9. Measurement system and model for simultaneously measuring 6DOF geometric errors.

    Science.gov (United States)

    Zhao, Yuqiong; Zhang, Bin; Feng, Qibo

    2017-09-04

    A measurement system to simultaneously measure six degree-of-freedom (6DOF) geometric errors is proposed. The measurement method is based on a combination of mono-frequency laser interferometry and laser fiber collimation. A simpler and more integrated optical configuration is designed. To compensate for the measurement errors introduced by error crosstalk, element fabrication error, laser beam drift, and nonparallelism of two measurement beam, a unified measurement model, which can improve the measurement accuracy, is deduced and established using the ray-tracing method. A numerical simulation using the optical design software Zemax is conducted, and the results verify the correctness of the model. Several experiments are performed to demonstrate the feasibility and effectiveness of the proposed system and measurement model.

  10. Constraining new physics with collider measurements of Standard Model signatures

    Energy Technology Data Exchange (ETDEWEB)

    Butterworth, Jonathan M. [Department of Physics and Astronomy, University College London,Gower St., London, WC1E 6BT (United Kingdom); Grellscheid, David [IPPP, Department of Physics, Durham University,Durham, DH1 3LE (United Kingdom); Krämer, Michael; Sarrazin, Björn [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University,Sommerfeldstr. 16, 52056 Aachen (Germany); Yallup, David [Department of Physics and Astronomy, University College London,Gower St., London, WC1E 6BT (United Kingdom)

    2017-03-14

    A new method providing general consistency constraints for Beyond-the-Standard-Model (BSM) theories, using measurements at particle colliders, is presented. The method, ‘Constraints On New Theories Using Rivet’, CONTUR, exploits the fact that particle-level differential measurements made in fiducial regions of phase-space have a high degree of model-independence. These measurements can therefore be compared to BSM physics implemented in Monte Carlo generators in a very generic way, allowing a wider array of final states to be considered than is typically the case. The CONTUR approach should be seen as complementary to the discovery potential of direct searches, being designed to eliminate inconsistent BSM proposals in a context where many (but perhaps not all) measurements are consistent with the Standard Model. We demonstrate, using a competitive simplified dark matter model, the power of this approach. The CONTUR method is highly scaleable to other models and future measurements.

  11. Parametric model measurement: reframing traditional measurement ideas in neuropsychological practice and research.

    Science.gov (United States)

    Brown, Gregory G; Thomas, Michael L; Patt, Virginie

    Neuropsychology is an applied measurement field with its psychometric work primarily built upon classical test theory (CTT). We describe a series of psychometric models to supplement the use of CTT in neuropsychological research and test development. We introduce increasingly complex psychometric models as measurement algebras, which include model parameters that represent abilities and item properties. Within this framework of parametric model measurement (PMM), neuropsychological assessment involves the estimation of model parameters with ability parameter values assuming the role of test 'scores'. Moreover, the traditional notion of measurement error is replaced by the notion of parameter estimation error, and the definition of reliability becomes linked to notions of item and test information. The more complex PMM approaches incorporate into the assessment of neuropsychological performance formal parametric models of behavior validated in the experimental psychology literature, along with item parameters. These PMM approaches endorse the use of experimental manipulations of model parameters to assess a test's construct representation. Strengths and weaknesses of these models are evaluated by their implications for measurement error conditional upon ability level, sensitivity to sample characteristics, computational challenges to parameter estimation, and construct validity. A family of parametric psychometric models can be used to assess latent processes of interest to neuropsychologists. By modeling latent abilities at the item level, psychometric studies in neuropsychology can investigate construct validity and measurement precision within a single framework and contribute to a unification of statistical methods within the framework of generalized latent variable modeling.

  12. Development of 3D statistical mandible models for cephalometric measurements

    International Nuclear Information System (INIS)

    Kim, Sung Goo; Yi, Won Jin; Hwang, Soon Jung; Choi, Soon Chul; Lee, Sam Sun; Heo, Min Suk; Huh, Kyung Hoe; Kim, Tae Il; Hong, Helen; Yoo, Ji Hyun

    2012-01-01

    The aim of this study was to provide sex-matched three-dimensional (3D) statistical shape models of the mandible, which would provide cephalometric parameters for 3D treatment planning and cephalometric measurements in orthognathic surgery. The subjects used to create the 3D shape models of the mandible included 23 males and 23 females. The mandibles were segmented semi-automatically from 3D facial CT images. Each individual mandible shape was reconstructed as a 3D surface model, which was parameterized to establish correspondence between different individual surfaces. The principal component analysis (PCA) applied to all mandible shapes produced a mean model and characteristic models of variation. The cephalometric parameters were measured directly from the mean models to evaluate the 3D shape models. The means of the measured parameters were compared with those from other conventional studies. The male and female 3D statistical mean models were developed from 23 individual mandibles, respectively. The male and female characteristic shapes of variation produced by PCA showed a large variability included in the individual mandibles. The cephalometric measurements from the developed models were very close to those from some conventional studies. We described the construction of 3D mandibular shape models and presented the application of the 3D mandibular template in cephalometric measurements. Optimal reference models determined from variations produced by PCA could be used for craniofacial patients with various types of skeletal shape.

  13. Development of 3D statistical mandible models for cephalometric measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Goo; Yi, Won Jin; Hwang, Soon Jung; Choi, Soon Chul; Lee, Sam Sun; Heo, Min Suk; Huh, Kyung Hoe; Kim, Tae Il [School of Dentistry, Seoul National University, Seoul (Korea, Republic of); Hong, Helen; Yoo, Ji Hyun [Division of Multimedia Engineering, Seoul Women' s University, Seoul (Korea, Republic of)

    2012-09-15

    The aim of this study was to provide sex-matched three-dimensional (3D) statistical shape models of the mandible, which would provide cephalometric parameters for 3D treatment planning and cephalometric measurements in orthognathic surgery. The subjects used to create the 3D shape models of the mandible included 23 males and 23 females. The mandibles were segmented semi-automatically from 3D facial CT images. Each individual mandible shape was reconstructed as a 3D surface model, which was parameterized to establish correspondence between different individual surfaces. The principal component analysis (PCA) applied to all mandible shapes produced a mean model and characteristic models of variation. The cephalometric parameters were measured directly from the mean models to evaluate the 3D shape models. The means of the measured parameters were compared with those from other conventional studies. The male and female 3D statistical mean models were developed from 23 individual mandibles, respectively. The male and female characteristic shapes of variation produced by PCA showed a large variability included in the individual mandibles. The cephalometric measurements from the developed models were very close to those from some conventional studies. We described the construction of 3D mandibular shape models and presented the application of the 3D mandibular template in cephalometric measurements. Optimal reference models determined from variations produced by PCA could be used for craniofacial patients with various types of skeletal shape.

  14. Validation of theoretical models through measured pavement response

    DEFF Research Database (Denmark)

    Ullidtz, Per

    1999-01-01

    mechanics was quite different from the measured stress, the peak theoretical value being only half of the measured value.On an instrumented pavement structure in the Danish Road Testing Machine, deflections were measured at the surface of the pavement under FWD loading. Different analytical models were...... then used to derive the elastic parameters of the pavement layeres, that would produce deflections matching the measured deflections. Stresses and strains were then calculated at the position of the gauges and compared to the measured values. It was found that all analytical models would predict the tensile...

  15. Modelling the effects of road traffic safety measures.

    Science.gov (United States)

    Lu, Meng

    2006-05-01

    A model is presented for assessing the effects of traffic safety measures, based on a breakdown of the process in underlying components of traffic safety (risk and consequence), and five (speed and conflict related) variables that influence these components, and are influenced by traffic safety measures. The relationships between measures, variables and components are modelled as coefficients. The focus is on probabilities rather than historical statistics, although in practice statistics may be needed to find values for the coefficients. The model may in general contribute to improve insight in the mechanisms between traffic safety measures and their safety effects. More specifically it allows comparative analysis of different types of measures by defining an effectiveness index, based on the coefficients. This index can be used to estimate absolute effects of advanced driver assistance systems (ADAS) related measures from absolute effects of substitutional (in terms of safety effects) infrastructure measures.

  16. Conditioning a segmented stem profile model for two diameter measurements

    Science.gov (United States)

    Raymond L. Czaplewski; Joe P. Mcclure

    1988-01-01

    The stem profile model of Max and Burkhart (1976) is conditioned for dbh and a second upper stem measurement. This model was applied to a loblolly pine data set using diameter outside bark at 5.3m (i.e., height of 17.3 foot Girard form class) as the second upper stem measurement, and then compared to the original, unconditioned model. Variance of residuals was reduced...

  17. Academic Self-Concept: Modeling and Measuring for Science

    Science.gov (United States)

    Hardy, Graham

    2014-01-01

    In this study, the author developed a model to describe academic self-concept (ASC) in science and validated an instrument for its measurement. Unlike previous models of science ASC, which envisage science as a homogenous single global construct, this model took a multidimensional view by conceiving science self-concept as possessing distinctive…

  18. Bayesian modeling of measurement error in predictor variables

    NARCIS (Netherlands)

    Fox, Gerardus J.A.; Glas, Cornelis A.W.

    2003-01-01

    It is shown that measurement error in predictor variables can be modeled using item response theory (IRT). The predictor variables, that may be defined at any level of an hierarchical regression model, are treated as latent variables. The normal ogive model is used to describe the relation between

  19. Partially Observed Mixtures of IRT Models: An Extension of the Generalized Partial-Credit Model

    Science.gov (United States)

    Von Davier, Matthias; Yamamoto, Kentaro

    2004-01-01

    The generalized partial-credit model (GPCM) is used frequently in educational testing and in large-scale assessments for analyzing polytomous data. Special cases of the generalized partial-credit model are the partial-credit model--or Rasch model for ordinal data--and the two parameter logistic (2PL) model. This article extends the GPCM to the…

  20. Análise de Rasch aplicada a questionário sobre consumo de tabaco em escolares adolescentes = Rasch analysis applied to a questionnaire on tobacco use among adolescent students

    Directory of Open Access Journals (Sweden)

    Santos, Wendel Mombaque dos

    2014-01-01

    Conclusões: O uso do método de Rasch possibilitou verificar a exposição de cada participante às diferentes condições de exposição ao tabaco, assim como demonstrou que o questionário que avalia a exposição ao tabaco deve tratar cada questão com pesos diferentes

  1. A reliable and valid questionnaire was developed to measure computer vision syndrome at the workplace.

    Science.gov (United States)

    Seguí, María del Mar; Cabrero-García, Julio; Crespo, Ana; Verdú, José; Ronda, Elena

    2015-06-01

    To design and validate a questionnaire to measure visual symptoms related to exposure to computers in the workplace. Our computer vision syndrome questionnaire (CVS-Q) was based on a literature review and validated through discussion with experts and performance of a pretest, pilot test, and retest. Content validity was evaluated by occupational health, optometry, and ophthalmology experts. Rasch analysis was used in the psychometric evaluation of the questionnaire. Criterion validity was determined by calculating the sensitivity and specificity, receiver operator characteristic curve, and cutoff point. Test-retest repeatability was tested using the intraclass correlation coefficient (ICC) and concordance by Cohen's kappa (κ). The CVS-Q was developed with wide consensus among experts and was well accepted by the target group. It assesses the frequency and intensity of 16 symptoms using a single rating scale (symptom severity) that fits the Rasch rating scale model well. The questionnaire has sensitivity and specificity over 70% and achieved good test-retest repeatability both for the scores obtained [ICC = 0.802; 95% confidence interval (CI): 0.673, 0.884] and CVS classification (κ = 0.612; 95% CI: 0.384, 0.839). The CVS-Q has acceptable psychometric properties, making it a valid and reliable tool to control the visual health of computer workers, and can potentially be used in clinical trials and outcome research. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. A heteroscedastic measurement error model for method comparison data with replicate measurements.

    Science.gov (United States)

    Nawarathna, Lakshika S; Choudhary, Pankaj K

    2015-03-30

    Measurement error models offer a flexible framework for modeling data collected in studies comparing methods of quantitative measurement. These models generally make two simplifying assumptions: (i) the measurements are homoscedastic, and (ii) the unobservable true values of the methods are linearly related. One or both of these assumptions may be violated in practice. In particular, error variabilities of the methods may depend on the magnitude of measurement, or the true values may be nonlinearly related. Data with these features call for a heteroscedastic measurement error model that allows nonlinear relationships in the true values. We present such a model for the case when the measurements are replicated, discuss its fitting, and explain how to evaluate similarity of measurement methods and agreement between them, which are two common goals of data analysis, under this model. Model fitting involves dealing with lack of a closed form for the likelihood function. We consider estimation methods that approximate either the likelihood or the model to yield approximate maximum likelihood estimates. The fitting methods are evaluated in a simulation study. The proposed methodology is used to analyze a cholesterol dataset. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Incorporating measurement error in n = 1 psychological autoregressive modeling

    Science.gov (United States)

    Schuurman, Noémi K.; Houtveen, Jan H.; Hamaker, Ellen L.

    2015-01-01

    Measurement error is omnipresent in psychological data. However, the vast majority of applications of autoregressive time series analyses in psychology do not take measurement error into account. Disregarding measurement error when it is present in the data results in a bias of the autoregressive parameters. We discuss two models that take measurement error into account: An autoregressive model with a white noise term (AR+WN), and an autoregressive moving average (ARMA) model. In a simulation study we compare the parameter recovery performance of these models, and compare this performance for both a Bayesian and frequentist approach. We find that overall, the AR+WN model performs better. Furthermore, we find that for realistic (i.e., small) sample sizes, psychological research would benefit from a Bayesian approach in fitting these models. Finally, we illustrate the effect of disregarding measurement error in an AR(1) model by means of an empirical application on mood data in women. We find that, depending on the person, approximately 30–50% of the total variance was due to measurement error, and that disregarding this measurement error results in a substantial underestimation of the autoregressive parameters. PMID:26283988

  4. Comparison of conventional study model measurements and 3D digital study model measurements from laser scanned dental impressions

    Science.gov (United States)

    Nugrahani, F.; Jazaldi, F.; Noerhadi, N. A. I.

    2017-08-01

    The field of orthodontics is always evolving,and this includes the use of innovative technology. One type of orthodontic technology is the development of three-dimensional (3D) digital study models that replace conventional study models made by stone. This study aims to compare the mesio-distal teeth width, intercanine width, and intermolar width measurements between a 3D digital study model and a conventional study model. Twelve sets of upper arch dental impressions were taken from subjects with non-crowding teeth. The impressions were taken twice, once with alginate and once with polivinylsiloxane. The alginate impressions used in the conventional study model and the polivinylsiloxane impressions were scanned to obtain the 3D digital study model. Scanning was performed using a laser triangulation scanner device assembled by the School of Electrical Engineering and Informatics at the Institut Teknologi Bandung and David Laser Scan software. For the conventional model, themesio-distal width, intercanine width, and intermolar width were measured using digital calipers; in the 3D digital study model they were measured using software. There were no significant differences between the mesio-distal width, intercanine width, and intermolar width measurments between the conventional and 3D digital study models (p>0.05). Thus, measurements using 3D digital study models are as accurate as those obtained from conventional study models

  5. 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…

  6. Assessment of the Measurement Properties of the NHCAHPS Family Survey: A Rasch Scaling Approach

    Science.gov (United States)

    O'Connor, Matthew S.

    2013-01-01

    The introduction of the Consumer Assessment of Healthcare Providers and Systems (CAHPS), a family of survey instruments designed to capture and report people's experiences obtaining health care could soon add satisfaction as a consistent dimension of quality that skilled nursing facilities (SNFs) are required to assess and report. The SNF setting…

  7. 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

  8. 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…

  9. COMPREHENSIVE CHECK MEASUREMENT OF KEY PARAMETERS ON MODEL BELT CONVEYOR

    Directory of Open Access Journals (Sweden)

    Vlastimil MONI

    2013-07-01

    Full Text Available Complex measurements of characteristic parameters realised on a long distance model belt conveyor are described. The main objective was to complete and combine the regular measurements of electric power on drives of belt conveyors operated in Czech opencast mines with measurements of other physical quantities and to gain by this way an image of their mutual relations and relations of quantities derived from them. The paper includes a short description and results of the measurements on an experimental model conveyor with a closed material transport way.

  10. Measurements and Modeling of Conducted EMI in a Buck Chopper

    International Nuclear Information System (INIS)

    Fakhfakh, L.; Abid, S.; Ammous, A.

    2011-01-01

    The high increase of power electronic devices use (speed control, lighting, heating, automotive, etc...) requires the electrical, thermal and electromagnetic behavior studies. In this paper we developed a model to predict the conducted EMI level in a DC/DC converter. Measurement methodology was done using a network analyzer in order to evaluate the equivalent impedance model of each converter element. The full circuit model is then implemented in the Saber-trademark simulation tool using time domain simulation followed by fast Fourier transformation (FFT) in the frequency range 150 KHz -100 MHz. A comparison between simulation results and those obtained by measurements is used to validate the developed model. (author)

  11. FMCSA safety program effectiveness measurement: intervention model fiscal year 2009.

    Science.gov (United States)

    2013-04-01

    The Federal Motor Carrier Safety Administration (FMCSA), in cooperation with the researcher, has developed an analytic model to measure the effectiveness of roadside inspections and traffic enforcements in terms of crashes avoided, injuries avoided, ...

  12. A study of quality measures for protein threading models

    Directory of Open Access Journals (Sweden)

    Rychlewski Leszek

    2001-08-01

    Full Text Available Abstract Background Prediction of protein structures is one of the fundamental challenges in biology today. To fully understand how well different prediction methods perform, it is necessary to use measures that evaluate their performance. Every two years, starting in 1994, the CASP (Critical Assessment of protein Structure Prediction process has been organized to evaluate the ability of different predictors to blindly predict the structure of proteins. To capture different features of the models, several measures have been developed during the CASP processes. However, these measures have not been examined in detail before. In an attempt to develop fully automatic measures that can be used in CASP, as well as in other type of benchmarking experiments, we have compared twenty-one measures. These measures include the measures used in CASP3 and CASP2 as well as have measures introduced later. We have studied their ability to distinguish between the better and worse models submitted to CASP3 and the correlation between them. Results Using a small set of 1340 models for 23 different targets we show that most methods correlate with each other. Most pairs of measures show a correlation coefficient of about 0.5. The correlation is slightly higher for measures of similar types. We found that a significant problem when developing automatic measures is how to deal with proteins of different length. Also the comparisons between different measures is complicated as many measures are dependent on the size of the target. We show that the manual assessment can be reproduced to about 70% using automatic measures. Alignment independent measures, detects slightly more of the models with the correct fold, while alignment dependent measures agree better when selecting the best models for each target. Finally we show that using automatic measures would, to a large extent, reproduce the assessors ranking of the predictors at CASP3. Conclusions We show that given a

  13. Assessment of score- and Rasch-based methods for group comparison of longitudinal patient-reported outcomes with intermittent missing data (informative and non-informative).

    Science.gov (United States)

    de Bock, Élodie; Hardouin, Jean-Benoit; Blanchin, Myriam; Le Neel, Tanguy; Kubis, Gildas; Sébille, Véronique

    2015-01-01

    The purpose of this study was to identify the most adequate strategy for group comparison of longitudinal patient-reported outcomes in the presence of possibly informative intermittent missing data. Models coming from classical test theory (CTT) and item response theory (IRT) were compared. Two groups of patients' responses to dichotomous items with three times of assessment were simulated. Different cases were considered: presence or absence of a group effect and/or a time effect, a total of 100 or 200 patients, 4 or 7 items and two different values for the correlation coefficient of the latent trait between two consecutive times (0.4 or 0.9). Cases including informative and non-informative intermittent missing data were compared at different rates (15, 30 %). These simulated data were analyzed with CTT using score and mixed model (SM) and with IRT using longitudinal Rasch mixed model (LRM). The type I error, the power and the bias of the group effect estimations were compared between the two methods. This study showed that LRM performs better than SM. When the rate of missing data rose to 30 %, estimations were biased with SM mainly for informative missing data. Otherwise, LRM and SM methods were comparable concerning biases. However, regardless of the rate of intermittent missing data, power of LRM was higher compared to power of SM. In conclusion, LRM should be favored when the rate of missing data is higher than 15 %. For other cases, SM and LRM provide similar results.

  14. Stochastic higher spin six vertex model and Macdonald measures

    Science.gov (United States)

    Borodin, Alexei

    2018-02-01

    We prove an identity that relates the q-Laplace transform of the height function of a (higher spin inhomogeneous) stochastic six vertex model in a quadrant on one side and a multiplicative functional of a Macdonald measure on the other. The identity is used to prove the GUE Tracy-Widom asymptotics for two instances of the stochastic six vertex model via asymptotic analysis of the corresponding Schur measures.

  15. Numerical Modelling and Measurement in a Test Secondary Settling Tank

    DEFF Research Database (Denmark)

    Dahl, C.; Larsen, Torben; Petersen, O.

    1994-01-01

    sludge. Phenomena as free and hindered settling and the Bingham plastic characteristic of activated sludge suspensions are included in the numerical model. Further characterisation and test tank experiments are described. The characterisation experiments were designed to measure calibration parameters...... for model description of settling and density differences. In the test tank experiments, flow velocities and suspended sludge concentrations were measured with different tank inlet geomotry and hydraulic and sludge loads. The test tank experiments provided results for the calibration of the numerical model......A numerical model and measurements of flow and settling in activated sludge suspension is presented. The numerical model is an attempt to describe the complex and interrelated hydraulic and sedimentation phenomena by describing the turbulent flow field and the transport/dispersion of suspended...

  16. Using measurements for evaluation of black carbon modeling

    Directory of Open Access Journals (Sweden)

    S. Gilardoni

    2011-01-01

    Full Text Available The ever increasing use of air quality and climate model assessments to underpin economic, public health, and environmental policy decisions makes effective model evaluation critical. This paper discusses the properties of black carbon and light attenuation and absorption observations that are the key to a reliable evaluation of black carbon model and compares parametric and nonparametric statistical tools for the quantification of the agreement between models and observations. Black carbon concentrations are simulated with TM5/M7 global model from July 2002 to June 2003 at four remote sites (Alert, Jungfraujoch, Mace Head, and Trinidad Head and two regional background sites (Bondville and Ispra. Equivalent black carbon (EBC concentrations are calculated using light attenuation measurements from January 2000 to December 2005. Seasonal trends in the measurements are determined by fitting sinusoidal functions and the representativeness of the period simulated by the model is verified based on the scatter of the experimental values relative to the fit curves. When the resolution of the model grid is larger than 1° × 1°, it is recommended to verify that the measurement site is representative of the grid cell. For this purpose, equivalent black carbon measurements at Alert, Bondville and Trinidad Head are compared to light absorption and elemental carbon measurements performed at different sites inside the same model grid cells. Comparison of these equivalent black carbon and elemental carbon measurements indicates that uncertainties in black carbon optical properties can compromise the comparison between model and observations. During model evaluation it is important to examine the extent to which a model is able to simulate the variability in the observations over different integration periods as this will help to identify the most appropriate timescales. The agreement between model and observation is accurately described by the overlap of

  17. A Model and Measure of Mobile Communication Competence

    Science.gov (United States)

    Bakke, Emil

    2010-01-01

    This article deals with two studies that develop a measure and model of mobile communication competence (MCC). The first study examines the dimensionality of the measure by conducting an exploratory factor analysis on 350 students at a large university in the midwestern United States. Results identified six constructs across 24 items: willingness…

  18. Data Modeling for Measurements in the Metrology and Testing Fields

    CERN Document Server

    Pavese, Franco

    2009-01-01

    Offers a comprehensive set of modeling methods for data and uncertainty analysis. This work develops methods and computational tools to address general models that arise in practice, allowing for a more valid treatment of calibration and test data and providing an understanding of complex situations in measurement science

  19. Chain Risk Model for quantifying cost effectiveness of phytosanitary measures

    NARCIS (Netherlands)

    Benninga, J.; Hennen, W.H.G.J.; Schans, van de J.

    2010-01-01

    A Chain Risk Model (CRM) was developed for a cost effective assessment of phytosanitary measures. The CRM model can be applied to phytosanitary assessments of all agricultural product chains. In CRM, stages are connected by product volume flows with which pest infections can be spread from one stage

  20. Use of mathematical modeling in nuclear measurements projects

    International Nuclear Information System (INIS)

    Toubon, H.; Menaa, N.; Mirolo, L.; Ducoux, X.; Khalil, R. A.; Chany, P.; Devita, A.

    2011-01-01

    Mathematical modeling of nuclear measurement systems is not a new concept. The response of the measurement system is described using a pre-defined mathematical model that depends on a set of parameters. These parameters are determined using a limited set of experimental measurement points e.g. efficiency curve, dose rates... etc. The model that agrees with the few experimental points is called an experimentally validated model. Once these models have been validated, we use mathematical interpolation to find the parameters of interest. Sometimes, when measurements are not practical or are impossible extrapolation is implemented but with care. CANBERRA has been extensively using mathematical modeling for the design and calibration of large and sophisticated systems to create and optimize designs that would be prohibitively expensive with only experimental tools. The case studies that will be presented here are primarily performed with MCNP, CANBERRA's MERCURAD/PASCALYS and ISOCS (In Situ Object Counting Software). For benchmarking purposes, both Monte Carlo and ray-tracing based codes are inter-compared to show models consistency and add a degree of reliability to modeling results. (authors)

  1. Measurement error models with uncertainty about the error variance

    NARCIS (Netherlands)

    Oberski, D.L.; Satorra, A.

    2013-01-01

    It is well known that measurement error in observable variables induces bias in estimates in standard regression analysis and that structural equation models are a typical solution to this problem. Often, multiple indicator equations are subsumed as part of the structural equation model, allowing

  2. Urban traffic noise assessment by combining measurement and model results

    NARCIS (Netherlands)

    Eerden, F.J.M. van der; Graafland, F.; Wessels, P.W.; Basten, T.G.H.

    2013-01-01

    A model based monitoring system is applied on a local scale in an urban area to obtain a better understanding of the traffic noise situation. The system consists of a scalable sensor network and an engineering model. A better understanding is needed to take appropriate and cost efficient measures,

  3. Measures and limits of models of fixation selection.

    Directory of Open Access Journals (Sweden)

    Niklas Wilming

    Full Text Available Models of fixation selection are a central tool in the quest to understand how the human mind selects relevant information. Using this tool in the evaluation of competing claims often requires comparing different models' relative performance in predicting eye movements. However, studies use a wide variety of performance measures with markedly different properties, which makes a comparison difficult. We make three main contributions to this line of research: First we argue for a set of desirable properties, review commonly used measures, and conclude that no single measure unites all desirable properties. However the area under the ROC curve (a classification measure and the KL-divergence (a distance measure of probability distributions combine many desirable properties and allow a meaningful comparison of critical model performance. We give an analytical proof of the linearity of the ROC measure with respect to averaging over subjects and demonstrate an appropriate correction of entropy-based measures like KL-divergence for small sample sizes in the context of eye-tracking data. Second, we provide a lower bound and an upper bound of these measures, based on image-independent properties of fixation data and between subject consistency respectively. Based on these bounds it is possible to give a reference frame to judge the predictive power of a model of fixation selection. We provide open-source python code to compute the reference frame. Third, we show that the upper, between subject consistency bound holds only for models that predict averages of subject populations. Departing from this we show that incorporating subject-specific viewing behavior can generate predictions which surpass that upper bound. Taken together, these findings lay out the required information that allow a well-founded judgment of the quality of any model of fixation selection and should therefore be reported when a new model is introduced.

  4. Stochastic Measurement Models for Quantifying Lymphocyte Responses Using Flow Cytometry

    Science.gov (United States)

    Kan, Andrey; Pavlyshyn, Damian; Markham, John F.; Dowling, Mark R.; Heinzel, Susanne; Zhou, Jie H. S.; Marchingo, Julia M.; Hodgkin, Philip D.

    2016-01-01

    Adaptive immune responses are complex dynamic processes whereby B and T cells undergo division and differentiation triggered by pathogenic stimuli. Deregulation of the response can lead to severe consequences for the host organism ranging from immune deficiencies to autoimmunity. Tracking cell division and differentiation by flow cytometry using fluorescent probes is a major method for measuring progression of lymphocyte responses, both in vitro and in vivo. In turn, mathematical modeling of cell numbers derived from such measurements has led to significant biological discoveries, and plays an increasingly important role in lymphocyte research. Fitting an appropriate parameterized model to such data is the goal of these studies but significant challenges are presented by the variability in measurements. This variation results from the sum of experimental noise and intrinsic probabilistic differences in cells and is difficult to characterize analytically. Current model fitting methods adopt different simplifying assumptions to describe the distribution of such measurements and these assumptions have not been tested directly. To help inform the choice and application of appropriate methods of model fitting to such data we studied the errors associated with flow cytometry measurements from a wide variety of experiments. We found that the mean and variance of the noise were related by a power law with an exponent between 1.3 and 1.8 for different datasets. This violated the assumptions inherent to commonly used least squares, linear variance scaling and log-transformation based methods. As a result of these findings we propose a new measurement model that we justify both theoretically, from the maximum entropy standpoint, and empirically using collected data. Our evaluation suggests that the new model can be reliably used for model fitting across a variety of conditions. Our work provides a foundation for modeling measurements in flow cytometry experiments thus

  5. [Measurement model of carbon emission from forest fire: a review].

    Science.gov (United States)

    Hu, Hai-Qing; Wei, Shu-Jing; Jin, Sen; Sun, Long

    2012-05-01

    Forest fire is the main disturbance factor for forest ecosystem, and an important pathway of the decrease of vegetation- and soil carbon storage. Large amount of carbonaceous gases in forest fire can release into atmosphere, giving remarkable impacts on the atmospheric carbon balance and global climate change. To scientifically and effectively measure the carbonaceous gases emission from forest fire is of importance in understanding the significance of forest fire in the carbon balance and climate change. This paper reviewed the research progress in the measurement model of carbon emission from forest fire, which covered three critical issues, i. e., measurement methods of forest fire-induced total carbon emission and carbonaceous gases emission, affecting factors and measurement parameters of measurement model, and cause analysis of the uncertainty in the measurement of the carbon emissions. Three path selections to improve the quantitative measurement of the carbon emissions were proposed, i. e., using high resolution remote sensing data and improving algorithm and estimation accuracy of burned area in combining with effective fuel measurement model to improve the accuracy of the estimated fuel load, using high resolution remote sensing images combined with indoor controlled environment experiments, field measurements, and field ground surveys to determine the combustion efficiency, and combining indoor controlled environment experiments with field air sampling to determine the emission factors and emission ratio.

  6. Reliability of Composite Dichotomous Measurements

    Czech Academy of Sciences Publication Activity Database

    Martinková, Patrícia; Zvára, Karel

    2010-01-01

    Roč. 6, č. 2 (2010), s. 103-109 ISSN 1801-5603 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : reliability * binary data * logistic regression * Cronbach alpha * Rasch model * myocardial perfusion diagnosis Subject RIV: BB - Applied Statistics, Operational Research http://www.ejbi.cz/articles/201012/65/1.html

  7. A Simulation Model for Measuring Customer Satisfaction through Employee Satisfaction

    Science.gov (United States)

    Zondiros, Dimitris; Konstantopoulos, Nikolaos; Tomaras, Petros

    2007-12-01

    Customer satisfaction is defined as a measure of how a firm's product or service performs compared to customer's expectations. It has long been a subject of research due to its importance for measuring marketing and business performance. A lot of models have been developed for its measurement. This paper propose a simulation model using employee satisfaction as one of the most important factors leading to customer satisfaction (the others being expectations and disconfirmation of expectations). Data obtained from a two-year survey in customers of banks in Greece were used. The application of three approaches regarding employee satisfaction resulted in greater customer satisfaction when there is serious effort to keep employees satisfied.

  8. ARMA modelling of neutron stochastic processes with large measurement noise

    International Nuclear Information System (INIS)

    Zavaljevski, N.; Kostic, Lj.; Pesic, M.

    1994-01-01

    An autoregressive moving average (ARMA) model of the neutron fluctuations with large measurement noise is derived from langevin stochastic equations and validated using time series data obtained during prompt neutron decay constant measurements at the zero power reactor RB in Vinca. Model parameters are estimated using the maximum likelihood (ML) off-line algorithm and an adaptive pole estimation algorithm based on the recursive prediction error method (RPE). The results show that subcriticality can be determined from real data with high measurement noise using much shorter statistical sample than in standard methods. (author)

  9. Identification of GMS friction model without friction force measurement

    International Nuclear Information System (INIS)

    Grami, Said; Aissaoui, Hicham

    2011-01-01

    This paper deals with an online identification of the Generalized Maxwell Slip (GMS) friction model for both presliding and sliding regime at the same time. This identification is based on robust adaptive observer without friction force measurement. To apply the observer, a new approach of calculating the filtered friction force from the measurable signals is introduced. Moreover, two approximations are proposed to get the friction model linear over the unknown parameters and an approach of suitable filtering is introduced to guarantee the continuity of the model. Simulation results are presented to prove the efficiency of the approach of identification.

  10. Impact of AMS-02 Measurements on Reducing GCR Model Uncertainties

    Science.gov (United States)

    Slaba, T. C.; O'Neill, P. M.; Golge, S.; Norbury, J. W.

    2015-01-01

    For vehicle design, shield optimization, mission planning, and astronaut risk assessment, the exposure from galactic cosmic rays (GCR) poses a significant and complex problem both in low Earth orbit and in deep space. To address this problem, various computational tools have been developed to quantify the exposure and risk in a wide range of scenarios. Generally, the tool used to describe the ambient GCR environment provides the input into subsequent computational tools and is therefore a critical component of end-to-end procedures. Over the past few years, several researchers have independently and very carefully compared some of the widely used GCR models to more rigorously characterize model differences and quantify uncertainties. All of the GCR models studied rely heavily on calibrating to available near-Earth measurements of GCR particle energy spectra, typically over restricted energy regions and short time periods. In this work, we first review recent sensitivity studies quantifying the ions and energies in the ambient GCR environment of greatest importance to exposure quantities behind shielding. Currently available measurements used to calibrate and validate GCR models are also summarized within this context. It is shown that the AMS-II measurements will fill a critically important gap in the measurement database. The emergence of AMS-II measurements also provides a unique opportunity to validate existing models against measurements that were not used to calibrate free parameters in the empirical descriptions. Discussion is given regarding rigorous approaches to implement the independent validation efforts, followed by recalibration of empirical parameters.

  11. A measurement model of multiple intelligence profiles of management graduates

    Science.gov (United States)

    Krishnan, Heamalatha; Awang, Siti Rahmah

    2017-05-01

    In this study, developing a fit measurement model and identifying the best fitting items to represent Howard Gardner's nine intelligences namely, musical intelligence, bodily-kinaesthetic intelligence, mathematical/logical intelligence, visual/spatial intelligence, verbal/linguistic intelligence, interpersonal intelligence, intrapersonal intelligence, naturalist intelligence and spiritual intelligence are the main interest in order to enhance the opportunities of the management graduates for employability. In order to develop a fit measurement model, Structural Equation Modeling (SEM) was applied. A psychometric test which is the Ability Test in Employment (ATIEm) was used as the instrument to measure the existence of nine types of intelligence of 137 University Teknikal Malaysia Melaka (UTeM) management graduates for job placement purposes. The initial measurement model contains nine unobserved variables and each unobserved variable is measured by ten observed variables. Finally, the modified measurement model deemed to improve the Normed chi-square (NC) = 1.331; Incremental Fit Index (IFI) = 0.940 and Root Mean Square of Approximation (RMSEA) = 0.049 was developed. The findings showed that the UTeM management graduates possessed all nine intelligences either high or low. Musical intelligence, mathematical/logical intelligence, naturalist intelligence and spiritual intelligence contributed highest loadings on certain items. However, most of the intelligences such as bodily kinaesthetic intelligence, visual/spatial intelligence, verbal/linguistic intelligence interpersonal intelligence and intrapersonal intelligence possessed by UTeM management graduates are just at the borderline.

  12. Absorptivity Measurements and Heat Source Modeling to Simulate Laser Cladding

    Science.gov (United States)

    Wirth, Florian; Eisenbarth, Daniel; Wegener, Konrad

    The laser cladding process gains importance, as it does not only allow the application of surface coatings, but also additive manufacturing of three-dimensional parts. In both cases, process simulation can contribute to process optimization. Heat source modeling is one of the main issues for an accurate model and simulation of the laser cladding process. While the laser beam intensity distribution is readily known, the other two main effects on the process' heat input are non-trivial. Namely the measurement of the absorptivity of the applied materials as well as the powder attenuation. Therefore, calorimetry measurements were carried out. The measurement method and the measurement results for laser cladding of Stellite 6 on structural steel S 235 and for the processing of Inconel 625 are presented both using a CO2 laser as well as a high power diode laser (HPDL). Additionally, a heat source model is deduced.

  13. Overview of the Standard Model Measurements with the ATLAS Detector

    CERN Document Server

    Liu, Yanwen; The ATLAS collaboration

    2017-01-01

    The ATLAS Collaboration is engaged in precision measurement of fundamental Standard Model parameters, such as the W boson mass, the weak-mixing angle or the strong coupling constant. In addition, the production cross-sections of a large variety of final states involving high energetic jets, photons as well as single and multi vector bosons are measured multi differentially at several center of mass energies. This allows to test perturbative QCD calculations to highest precision. In addition, these measurements allow also to test models beyond the SM, e.g. those leading to anomalous gauge couplings. In this talk, we give a broad overview of the Standard Model measurement campaign of the ATLAS collaboration, where selected topics will be discussed in more detail.

  14. Magnetic field measurements of JT-60SA CS model coil

    Energy Technology Data Exchange (ETDEWEB)

    Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2015-01-15

    Highlights: • Magnetic fields of the JT-60SA CS model coil were measured. • While the coil current was held constant at 20 kA, magnetic fields varied slightly with several different long time constants. • We investigated coils consisting of CIC conductors and having long time constants. - Abstract: In a cold test of the JT-60SA CS model coil, which has a quad-pancake configuration consisting of a Nb{sub 3}Sn cable-in-conduit (CIC) conductor, magnetic fields were measured using Hall sensors. For a holding coil current of 20 kA, measured magnetic fields varied slightly with long time constants in the range 17–571 s, which was much longer than the time constant derived from a measurement using a short straight sample. To validate the measurements, the magnetic fields of the model coil were calculated using a computational model representing the positions of Nb{sub 3}Sn strands inside the CIC conductor. The calculated results were in good agreement with the measurements. Consequently, the validity of the magnetic field measurements was confirmed. Next, we investigated other coils consisting of CIC conductors and having long time constants. The only commonality among the coils was the use of CIC conductors. At present, there is no obvious way to prevent generation of such magnetic-field variations with long time constants.

  15. Impact of Rating Scale Categories on Reliability and Fit Statistics of the Malay Spiritual Well-Being Scale using Rasch Analysis.

    Science.gov (United States)

    Daher, Aqil Mohammad; Ahmad, Syed Hassan; Winn, Than; Selamat, Mohd Ikhsan

    2015-01-01

    Few studies have employed the item response theory in examining reliability. We conducted this study to examine the effect of Rating Scale Categories (RSCs) on the reliability and fit statistics of the Malay Spiritual Well-Being Scale, employing the Rasch model. The Malay Spiritual Well-Being Scale (SWBS) with the original six; three and four newly structured RSCs was distributed randomly among three different samples of 50 participants each. The mean age of respondents in the three samples ranged between 36 and 39 years old. The majority was female in all samples, and Islam was the most prevalent religion among the respondents. The predominating race was Malay, followed by Chinese and Indian. The original six RSCs indicated better targeting of 0.99 and smallest model error of 0.24. The Infit Mnsq (mean square) and Zstd (Z standard) of the six RSCs were "1.1"and "-0.1"respectively. The six RSCs achieved the highest person and item reliabilities of 0.86 and 0.85 respectively. These reliabilities yielded the highest person (2.46) and item (2.38) separation indices compared to other the RSCs. The person and item reliability and, to a lesser extent, the fit statistics, were better with the six RSCs compared to the four and three RSCs.

  16. Modelling measurement microphones using BEM with visco-thermal losses

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Juhl, Peter Møller

    2012-01-01

    For many decades, models that can explain the behaviour of measurement condenser microphones have been proposed in the literature. These devices have an apparently simple working principle, a charged capacitor whose charge varies when one of its electrodes, the diaphragm, moves as a result of sound...... waves. However, measurement microphones must be manufactured very carefully due to their sensitivity to small changes of their physical parameters. There are different elements in a microphone, the diaphragm, the gap behind it, a back cavity, a vent for pressure equalization and an external medium. All...... visco-thermal losses is used to model measurement condenser microphones. The models presented are fully coupled and include a FEM model of the diaphragm. The behaviour of the acoustic variables in the gap and the effect of the pressure equalization vent are discussed, as well as the practical difficulty...

  17. DISCERNING EXOPLANET MIGRATION MODELS USING SPIN-ORBIT MEASUREMENTS

    International Nuclear Information System (INIS)

    Morton, Timothy D.; Johnson, John Asher

    2011-01-01

    We investigate the current sample of exoplanet spin-orbit measurements to determine whether a dominant planet migration channel can be identified, and at what confidence. We use the predictions of Kozai migration plus tidal friction and planet-planet scattering as our misalignment models, and we allow for a fraction of intrinsically aligned systems, explainable by disk migration. Bayesian model comparison demonstrates that the current sample of 32 spin-orbit measurements strongly favors a two-mode migration scenario combining planet-planet scattering and disk migration over a single-mode Kozai migration scenario. Our analysis indicates that between 34% and 76% of close-in planets (95% confidence) migrated via planet-planet scattering. Separately analyzing the subsample of 12 stars with T eff >6250 K-which Winn et al. predict to be the only type of stars to maintain their primordial misalignments-we find that the data favor a single-mode scattering model over Kozai with 85% confidence. We also assess the number of additional hot star spin-orbit measurements that will likely be necessary to provide a more confident model selection, finding that an additional 20-30 measurement has a >50% chance of resulting in a 95% confident model selection, if the current model selection is correct. While we test only the predictions of particular Kozai and scattering migration models in this work, our methods may be used to test the predictions of any other spin-orbit misaligning mechanism.

  18. Model measurements in the cryogenic National Transonic Facility - An overview

    Science.gov (United States)

    Holmes, H. K.

    1985-01-01

    In the operation of the National Transonic Facility (NTF) higher Reynolds numbers are obtained on the basis of a utilization of low operational temperatures and high pressures. Liquid nitrogen is used as cryogenic medium, and temperatures in the range from -320 F to 160 F can be employed. A maximum pressure of 130 psi is specified, while the NTF design parameter for the Reynolds number is 120,000,000. In view of the new requirements regarding the measurement systems, major developments had to be undertaken in virtually all wind tunnel measurement areas and, in addition, some new measurement systems were needed. Attention is given to force measurement, pressure measurement, model attitude, model deformation, and the data system.

  19. Measuring and modeling salience with the theory of visual attention.

    Science.gov (United States)

    Krüger, Alexander; Tünnermann, Jan; Scharlau, Ingrid

    2017-08-01

    For almost three decades, the theory of visual attention (TVA) has been successful in mathematically describing and explaining a wide variety of phenomena in visual selection and recognition with high quantitative precision. Interestingly, the influence of feature contrast on attention has been included in TVA only recently, although it has been extensively studied outside the TVA framework. The present approach further develops this extension of TVA's scope by measuring and modeling salience. An empirical measure of salience is achieved by linking different (orientation and luminance) contrasts to a TVA parameter. In the modeling part, the function relating feature contrasts to salience is described mathematically and tested against alternatives by Bayesian model comparison. This model comparison reveals that the power function is an appropriate model of salience growth in the dimensions of orientation and luminance contrast. Furthermore, if contrasts from the two dimensions are combined, salience adds up additively.

  20. Constitutive modelling of an arterial wall supported by microscopic measurements

    Directory of Open Access Journals (Sweden)

    Vychytil J.

    2012-06-01

    Full Text Available An idealized model of an arterial wall is proposed as a two-layer system. Distinct mechanical response of each layer is taken into account considering two types of strain energy functions in the hyperelasticity framework. The outer layer, considered as a fibre-reinforced composite, is modelled using the structural model of Holzapfel. The inner layer, on the other hand, is represented by a two-scale model mimicing smooth muscle tissue. For this model, material parameters such as shape, volume fraction and orientation of smooth muscle cells are determined using the microscopic measurements. The resulting model of an arterial ring is stretched axially and loaded with inner pressure to simulate the mechanical response of a porcine arterial segment during inflation and axial stretching. Good agreement of the model prediction with experimental data is promising for further progress.

  1. Modeling dendrite density from magnetic resonance diffusion measurements

    DEFF Research Database (Denmark)

    Jespersen, Sune Nørhøj; Kroenke, CD; Østergaard, Leif

    2007-01-01

    in this model: (i) the dendrites and axons, which are modeled as long cylinders with two diffusion coefficients, parallel (DL) and perpendicular (DT) to the cylindrical axis, and (ii) an isotropic monoexponential diffusion component describing water diffusion within and across all other structures, i.......e., in extracellular space and glia cells. The model parameters are estimated from 153 diffusion-weighted images acquired from a formalin-fixed baboon brain. A close correspondence between the data and the signal model is found, with the model parameters consistent with literature values. The model provides......Diffusion-weighted imaging (DWI) provides a noninvasive tool to probe tissue microstructure. We propose a simplified model of neural cytoarchitecture intended to capture the essential features important for water diffusion as measured by NMR. Two components contribute to the NMR signal...

  2. Global Atmosphere Watch Workshop on Measurement-Model ...

    Science.gov (United States)

    The World Meteorological Organization’s (WMO) Global Atmosphere Watch (GAW) Programme coordinates high-quality observations of atmospheric composition from global to local scales with the aim to drive high-quality and high-impact science while co-producing a new generation of products and services. In line with this vision, GAW’s Scientific Advisory Group for Total Atmospheric Deposition (SAG-TAD) has a mandate to produce global maps of wet, dry and total atmospheric deposition for important atmospheric chemicals to enable research into biogeochemical cycles and assessments of ecosystem and human health effects. The most suitable scientific approach for this activity is the emerging technique of measurement-model fusion for total atmospheric deposition. This technique requires global-scale measurements of atmospheric trace gases, particles, precipitation composition and precipitation depth, as well as predictions of the same from global/regional chemical transport models. The fusion of measurement and model results requires data assimilation and mapping techniques. The objective of the GAW Workshop on Measurement-Model Fusion for Global Total Atmospheric Deposition (MMF-GTAD), an initiative of the SAG-TAD, was to review the state-of-the-science and explore the feasibility and methodology of producing, on a routine retrospective basis, global maps of atmospheric gas and aerosol concentrations as well as wet, dry and total deposition via measurement-model

  3. Multitasking TORT Under UNICOS: Parallel Performance Models and Measurements

    International Nuclear Information System (INIS)

    Azmy, Y.Y.; Barnett, D.A.

    1999-01-01

    The existing parallel algorithms in the TORT discrete ordinates were updated to function in a UNI-COS environment. A performance model for the parallel overhead was derived for the existing algorithms. The largest contributors to the parallel overhead were identified and a new algorithm was developed. A parallel overhead model was also derived for the new algorithm. The results of the comparison of parallel performance models were compared to applications of the code to two TORT standard test problems and a large production problem. The parallel performance models agree well with the measured parallel overhead

  4. Multitasking TORT under UNICOS: Parallel performance models and measurements

    International Nuclear Information System (INIS)

    Barnett, A.; Azmy, Y.Y.

    1999-01-01

    The existing parallel algorithms in the TORT discrete ordinates code were updated to function in a UNICOS environment. A performance model for the parallel overhead was derived for the existing algorithms. The largest contributors to the parallel overhead were identified and a new algorithm was developed. A parallel overhead model was also derived for the new algorithm. The results of the comparison of parallel performance models were compared to applications of the code to two TORT standard test problems and a large production problem. The parallel performance models agree well with the measured parallel overhead

  5. Modelling and measurement of a moving magnet linear compressor performance

    International Nuclear Information System (INIS)

    Liang, Kun; Stone, Richard; Davies, Gareth; Dadd, Mike; Bailey, Paul

    2014-01-01

    A novel moving magnet linear compressor with clearance seals and flexure bearings has been designed and constructed. It is suitable for a refrigeration system with a compact heat exchanger, such as would be needed for CPU cooling. The performance of the compressor has been experimentally evaluated with nitrogen and a mathematical model has been developed to evaluate the performance of the linear compressor. The results from the compressor model and the measurements have been compared in terms of cylinder pressure, the ‘P–V’ loop, stroke, mass flow rate and shaft power. The cylinder pressure was not measured directly but was derived from the compressor dynamics and the motor magnetic force characteristics. The comparisons indicate that the compressor model is well validated and can be used to study the performance of this type of compressor, to help with design optimization and the identification of key parameters affecting the system transients. The electrical and thermodynamic losses were also investigated, particularly for the design point (stroke of 13 mm and pressure ratio of 3.0), since a full understanding of these can lead to an increase in compressor efficiency. - Highlights: • Model predictions of the performance of a novel moving magnet linear compressor. • Prototype linear compressor performance measurements using nitrogen. • Reconstruction of P–V loops using a model of the dynamics and electromagnetics. • Close agreement between the model and measurements for the P–V loops. • The design point motor efficiency was 74%, with potential improvements identified

  6. Immersive Data Comprehension: Visualizing Uncertainty in Measurable Models

    Directory of Open Access Journals (Sweden)

    Pere eBrunet

    2015-09-01

    Full Text Available Recent advances in 3D scanning technologies have opened new possibilities in a broad range of applications includingcultural heritage, medicine, civil engineering and urban planning. Virtual Reality systems can provide new tools toprofessionals that want to understand acquired 3D models. In this paper, we review the concept of data comprehension with an emphasis on visualization and inspection tools on immersive setups. We claim that in most application fields, data comprehension requires model measurements which in turn should be based on the explicit visualization of uncertainty. As 3D digital representations are not faithful, information on their fidelity at local level should be included in the model itself as uncertainty bounds. We propose the concept of Measurable 3D Models as digital models that explicitly encode local uncertainty bounds related to their quality. We claim that professionals and experts can strongly benefit from immersive interaction through new specific, fidelity-aware measurement tools which can facilitate 3D data comprehension. Since noise and processing errors are ubiquitous in acquired datasets, we discuss the estimation, representation and visualization of data uncertainty. We show that, based on typical user requirements in Cultural Heritage and other domains, application-oriented measuring tools in 3D models must consider uncertainty and local error bounds. We also discuss the requirements of immersive interaction tools for the comprehension of huge 3D and nD datasets acquired from real objects.

  7. Pathloss Measurements and Modeling for UAVs Connected to Cellular Networks

    DEFF Research Database (Denmark)

    Amorim, Rafhael Medeiros de; Mogensen, Preben Elgaard; Sørensen, Troels Bundgaard

    2017-01-01

    . The measurements were conducted in an operating LTE network (850 MHz), using a commercial cell phone, placed inside the frame of the UAV. Trials were conducted for UAV flying at 5 different heights measured above ground level (20, 40, 60, 80 and 100m) and a pathloss regression line was obtained from results. Then......This paper assess field measurements, as part of the investigation of the suitability of cellular networks for providing connectivity to UAVs (unmanned aerial vehicles). Evaluation is done by means of field measurements obtained in a rural environment in Denmark with an airbone UAV......, downlink (DL) SINR levels obtained during flight measurements are also presented. An important result obtained from the measurents reveal that there is a height-related DL SINR degradation. Three main sources of uncertainty on the pathloss model that could be responsible for the SINR degradation are also...

  8. Dispersion Modeling Using Ensemble Forecasts Compared to ETEX Measurements.

    Science.gov (United States)

    Straume, Anne Grete; N'dri Koffi, Ernest; Nodop, Katrin

    1998-11-01

    Numerous numerical models are developed to predict long-range transport of hazardous air pollution in connection with accidental releases. When evaluating and improving such a model, it is important to detect uncertainties connected to the meteorological input data. A Lagrangian dispersion model, the Severe Nuclear Accident Program, is used here to investigate the effect of errors in the meteorological input data due to analysis error. An ensemble forecast, produced at the European Centre for Medium-Range Weather Forecasts, is then used as model input. The ensemble forecast members are generated by perturbing the initial meteorological fields of the weather forecast. The perturbations are calculated from singular vectors meant to represent possible forecast developments generated by instabilities in the atmospheric flow during the early part of the forecast. The instabilities are generated by errors in the analyzed fields. Puff predictions from the dispersion model, using ensemble forecast input, are compared, and a large spread in the predicted puff evolutions is found. This shows that the quality of the meteorological input data is important for the success of the dispersion model. In order to evaluate the dispersion model, the calculations are compared with measurements from the European Tracer Experiment. The model manages to predict the measured puff evolution concerning shape and time of arrival to a fairly high extent, up to 60 h after the start of the release. The modeled puff is still too narrow in the advection direction.

  9. Chemical Thermodynamics of Aqueous Atmospheric Aerosols: Modeling and Microfluidic Measurements

    Science.gov (United States)

    Nandy, L.; Dutcher, C. S.

    2017-12-01

    Accurate predictions of gas-liquid-solid equilibrium phase partitioning of atmospheric aerosols by thermodynamic modeling and measurements is critical for determining particle composition and internal structure at conditions relevant to the atmosphere. Organic acids that originate from biomass burning, and direct biogenic emission make up a significant fraction of the organic mass in atmospheric aerosol particles. In addition, inorganic compounds like ammonium sulfate and sea salt also exist in atmospheric aerosols, that results in a mixture of single, double or triple charged ions, and non-dissociated and partially dissociated organic acids. Statistical mechanics based on a multilayer adsorption isotherm model can be applied to these complex aqueous environments for predictions of thermodynamic properties. In this work, thermodynamic analytic predictive models are developed for multicomponent aqueous solutions (consisting of partially dissociating organic and inorganic acids, fully dissociating symmetric and asymmetric electrolytes, and neutral organic compounds) over the entire relative humidity range, that represent a significant advancement towards a fully predictive model. The model is also developed at varied temperatures for electrolytes and organic compounds the data for which are available at different temperatures. In addition to the modeling approach, water loss of multicomponent aerosol particles is measured by microfluidic experiments to parameterize and validate the model. In the experimental microfluidic measurements, atmospheric aerosol droplet chemical mimics (organic acids and secondary organic aerosol (SOA) samples) are generated in microfluidic channels and stored and imaged in passive traps until dehydration to study the influence of relative humidity and water loss on phase behavior.

  10. Validation of the CMT Pediatric Scale as an outcome measure of disability

    Science.gov (United States)

    Burns, Joshua; Ouvrier, Robert; Estilow, Tim; Shy, Rosemary; Laurá, Matilde; Pallant, Julie F.; Lek, Monkol; Muntoni, Francesco; Reilly, Mary M.; Pareyson, Davide; Acsadi, Gyula; Shy, Michael E.; Finkel, Richard S.

    2012-01-01

    Objective Charcot-Marie-Tooth disease (CMT) is a common heritable peripheral neuropathy. There is no treatment for any form of CMT although clinical trials are increasingly occurring. Patients usually develop symptoms during the first two decades of life but there are no established outcome measures of disease severity or response to treatment. We identified a set of items that represent a range of impairment levels and conducted a series of validation studies to build a patient-centered multi-item rating scale of disability for children with CMT. Methods As part of the Inherited Neuropathies Consortium, patients aged 3–20 years with a variety of CMT types were recruited from the USA, UK, Italy and Australia. Initial development stages involved: definition of the construct, item pool generation, peer review and pilot testing. Based on data from 172 patients, a series of validation studies were conducted, including: item and factor analysis, reliability testing, Rasch modeling and sensitivity analysis. Results Seven areas for measurement were identified (strength, dexterity, sensation, gait, balance, power, endurance), and a psychometrically robust 11-item scale constructed (Charcot-Marie-Tooth disease Pediatric Scale: CMTPedS). Rasch analysis supported the viability of the CMTPedS as a unidimensional measure of disability in children with CMT. It showed good overall model fit, no evidence of misfitting items, no person misfit and it was well targeted for children with CMT. Interpretation The CMTPedS is a well-tolerated outcome measure that can be completed in 25-minutes. It is a reliable, valid and sensitive global measure of disability for children with CMT from the age of 3 years. PMID:22522479

  11. 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.

  12. Model Predictive Control of Wind Turbines using Uncertain LIDAR Measurements

    DEFF Research Database (Denmark)

    Mirzaei, Mahmood; Soltani, Mohsen; Poulsen, Niels Kjølstad

    2013-01-01

    , we simplify state prediction for the MPC. Consequently, the control problem of the nonlinear system is simplified into a quadratic programming. We consider uncertainty in the wind propagation time, which is the traveling time of wind from the LIDAR measurement point to the rotor. An algorithm based......The problem of Model predictive control (MPC) of wind turbines using uncertain LIDAR (LIght Detection And Ranging) measurements is considered. A nonlinear dynamical model of the wind turbine is obtained. We linearize the obtained nonlinear model for different operating points, which are determined...... on wind speed estimation and measurements from the LIDAR is devised to find an estimate of the delay and compensate for it before it is used in the controller. Comparisons between the MPC with error compensation, the MPC without error compensation and an MPC with re-linearization at each sample point...

  13. The development and validation of a multidimensional sum-scaling questionnaire to measure patient-reported outcomes in acute respiratory tract infections in primary care: the acute respiratory tract infection questionnaire.

    Science.gov (United States)

    Aabenhus, Rune; Thorsen, Hanne; Siersma, Volkert; Brodersen, John

    2013-01-01

    Patient-reported outcomes are seldom validated measures in clinical trials of acute respiratory tract infections (ARTIs) in primary care. We developed and validated a patient-reported outcome sum-scaling measure to assess the severity and functional impacts of ARTIs. Qualitative interviews and field testing among adults with an ARTI were conducted to ascertain a high degree of face and content validity of the questionnaire. Subsequently, a draft version of the Acute Respiratory Tract Infection Questionnaire (ARTIQ) was statistically validated by using the partial credit Rasch model to test dimensionality, objectivity, and reliability of items. Test of known groups' validity was conducted by comparing participants with and without an ARTI. The final version of the ARTIQ consisted of 38 items covering five dimensions (Physical-upper, Physical-lower, Psychological, Sleep, and Medicine) and five single items. All final dimensions were confirmed to fit the Rasch model, thus enabling sum-scaling of responses. The ARTIQ scores in participants with an ARTI were significantly higher than in those without ARTI (known groups' validity). A self-administered, multidimensional, sum-scaling questionnaire with high face and content validity and adequate psychometric properties for assessing severity and functional impacts from ARTIs in adults is available to clinical trials and audits in primary care. Copyright © 2013, International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc.

  14. Modeling and Measurements of Alternating Magnetic Signatures of Ships

    Directory of Open Access Journals (Sweden)

    Zhiqiang Wu

    2015-03-01

    Full Text Available The alternating electric and magnetic fields are new contributors to the global electromagnetic silencing of ships. Thus, modeling and measurements of alternating magnetic signatures should be a research priority in maritime engineering. In this paper, an alternating horizontal electric dipole is adopted to model the electromagnetic fields related with corrosion. Formulas for alternating magnetic fields generated in shallow sea by horizontal electric dipole are derived based on an air-sea-seabed three-layered model and a numerical computer is also applied. In addition, the alternating magnetic fields of a ship are measured using a tri-axis fluxgate magnetometer fixed in a swaying platform. The characteristics of these fields are analyzed. Finally, the equivalent dipole moment of the trial ship is predicted by contrasting the model results and the observed data.

  15. MEASURING THE DATA MODEL QUALITY IN THE ESUPPLY CHAINS

    Directory of Open Access Journals (Sweden)

    Zora Arsovski

    2012-03-01

    Full Text Available The implementation of Internet technology in business has enabled the development of e-business supply chains with large-scale information integration among all partners.The development of information systems (IS is based on the established business objectives whose achievement, among other things, directly depends on the quality of development and design of IS. In the process of analysis of the key elements of company operations in the supply chain, process model and corresponding data model are designed which should enable selection of appropriate information system architecture. The quality of the implemented information system, which supports e-supply chain, directly depends on the level of data model quality. One of the serious limitations of the data model is its complexity. With a large number of entities, data model is difficult to analyse, monitor and maintain. The problem gets bigger when looking at an integrated data model at the level of participating partners in the supply chain, where the data model usually consists of hundreds or even thousands of entities.The paper will analyse the key elements affecting the quality of data models and show their interactions and factors of significance. In addition, the paper presents various measures for assessing the quality of the data model on which it is possible to easily locate the problems and focus efforts in specific parts of a complex data model where it is not economically feasible to review every detail of the model.

  16. Gap probability - Measurements and models of a pecan orchard

    Science.gov (United States)

    Strahler, Alan H.; Li, Xiaowen; Moody, Aaron; Liu, YI

    1992-01-01

    Measurements and models are compared for gap probability in a pecan orchard. Measurements are based on panoramic photographs of 50* by 135 view angle made under the canopy looking upwards at regular positions along transects between orchard trees. The gap probability model is driven by geometric parameters at two levels-crown and leaf. Crown level parameters include the shape of the crown envelope and spacing of crowns; leaf level parameters include leaf size and shape, leaf area index, and leaf angle, all as functions of canopy position.

  17. Predicted and measured velocity distribution in a model heat exchanger

    International Nuclear Information System (INIS)

    Rhodes, D.B.; Carlucci, L.N.

    1984-01-01

    This paper presents a comparison between numerical predictions, using the porous media concept, and measurements of the two-dimensional isothermal shell-side velocity distributions in a model heat exchanger. Computations and measurements were done with and without tubes present in the model. The effect of tube-to-baffle leakage was also investigated. The comparison was made to validate certain porous media concepts used in a computer code being developed to predict the detailed shell-side flow in a wide range of shell-and-tube heat exchanger geometries

  18. Measurement model choice influenced randomized controlled trial results.

    Science.gov (United States)

    Gorter, Rosalie; Fox, Jean-Paul; Apeldoorn, Adri; Twisk, Jos

    2016-11-01

    In randomized controlled trials (RCTs), outcome variables are often patient-reported outcomes measured with questionnaires. Ideally, all available item information is used for score construction, which requires an item response theory (IRT) measurement model. However, in practice, the classical test theory measurement model (sum scores) is mostly used, and differences between response patterns leading to the same sum score are ignored. The enhanced differentiation between scores with IRT enables more precise estimation of individual trajectories over time and group effects. The objective of this study was to show the advantages of using IRT scores instead of sum scores when analyzing RCTs. Two studies are presented, a real-life RCT, and a simulation study. Both IRT and sum scores are used to measure the construct and are subsequently used as outcomes for effect calculation. The bias in RCT results is conditional on the measurement model that was used to construct the scores. A bias in estimated trend of around one standard deviation was found when sum scores were used, where IRT showed negligible bias. Accurate statistical inferences are made from an RCT study when using IRT to estimate construct measurements. The use of sum scores leads to incorrect RCT results. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Models to support students’ understanding of measuring area of circles

    Science.gov (United States)

    Rejeki, S.; Putri, R. I. I.

    2018-01-01

    Many studies showed that enormous students got confused about the concepts of measuring area of circles. The main reason is because mathematics classroom practices emphasized on memorizing formulas rather than understanding concepts. Therefore, in this study, a set of learning activities were designed as an innovation in learning area measurement of circles. The activities involved two models namely grid paper and reshaping which are respectively as a means and a strategy to support students’ learning of area measurement of circles. Design research was used as the research approach to achieve the aim. Thirty-eight of 8th graders in Indonesia were involved in this study. In this study, together with the contextual problems, the grid paper and reshaping sectors, which used as the models in this learning, helped the students to gradually develop their understanding of the area measurement of circles. The grid papers plays important role in comparing and estimating areas. Whereas, the reshaping sectors might support students’ understanding of the circumference and the area measurement of circles. Those two models could be the tool for promoting the informal theory of area measurement. Besides, the whole activities gave important role on distinguishing the area and perimeter of circles.

  20. Model for Measuring the Entrepreneurship of the Population

    OpenAIRE

    Drejeris, Rolandas; Beinoraitė, Šarūnė

    2014-01-01

    Population entrepreneurship is an important factor in the progress of economic development. This paper proposes a model of entrepreneurship measurement for comparing the level of entrepreneurship. The model consists of two main components, including criteria for the selection and determination of entrepreneurship by adapting the multi­criteria evaluation method TOPSIS. The most important criteria for identifying entrepreneurship cover the dynamics of the unemployment rate, the population of p...