Language-related differential item functioning between English and German PROMIS Depression items is negligible.

Science.gov (United States)

Fischer, H Felix; Wahl, Inka; Nolte, Sandra; Liegl, Gregor; Brähler, Elmar; Löwe, Bernd; Rose, Matthias

2017-12-01

To investigate differential item functioning (DIF) of PROMIS Depression items between US and German samples we compared data from the US PROMIS calibration sample (n = 780), a German general population survey (n = 2,500) and a German clinical sample (n = 621). DIF was assessed in an ordinal logistic regression framework, with 0.02 as criterion for R 2 -change and 0.096 for Raju's non-compensatory DIF. Item parameters were initially fixed to the PROMIS Depression metric; we used plausible values to account for uncertainty in depression estimates. Only four items showed DIF. Accounting for DIF led to negligible effects for the full item bank as well as a post hoc simulated computer-adaptive test (German general population sample was considerably lower compared to the US reference value of 50. Overall, we found little evidence for language DIF between US and German samples, which could be addressed by either replacing the DIF items by items not showing DIF or by scoring the short form in German samples with the corrected item parameters reported. Copyright © 2016 John Wiley & Sons, Ltd.

Assessing errors related to characteristics of the items measured

International Nuclear Information System (INIS)

Liggett, W.

1980-01-01

Errors that are related to some intrinsic property of the items measured are often encountered in nuclear material accounting. An example is the error in nondestructive assay measurements caused by uncorrected matrix effects. Nuclear material accounting requires for each materials type one measurement method for which bounds on these errors can be determined. If such a method is available, a second method might be used to reduce costs or to improve precision. If the measurement error for the first method is longer-tailed than Gaussian, then precision might be improved by measuring all items by both methods. 8 refs

Assessing Differential Item Functioning on the Test of Relational Reasoning

Directory of Open Access Journals (Sweden)

Denis Dumas

2018-03-01

Full Text Available The test of relational reasoning (TORR is designed to assess the ability to identify complex patterns within visuospatial stimuli. The TORR is designed for use in school and university settings, and therefore, its measurement invariance across diverse groups is critical. In this investigation, a large sample, representative of a major university on key demographic variables, was collected, and the resulting data were analyzed using a multi-group, multidimensional item-response theory model-comparison procedure. No significant differential item functioning was found on any of the TORR items across any of the demographic groups of interest. This finding is interpreted as evidence of the cultural fairness of the TORR, and potential test-development choices that may have contributed to that cultural fairness are discussed.

Decree of the State Office for Nuclear Safety No. 147/1997 of 17 June 1997 specifying lists of selected nuclear-related items and dual-use nuclear-related items

International Nuclear Information System (INIS)

1997-01-01

The core of the Decree consists of 2 lists, viz (a) the List of Selected Items (selected nuclear-related materials, equipment and technologies) which are subject to control regimes during imports, exports and transit; and (b) the List of Dual-Use Items (dual-use nuclear-related materials, equipment and technologies) which are subject to control regimes during imports and exports. Both Lists are based on the IAEA document INFCIRC/254/Rev.2/Part 2/Mod.1. (P.A.)

Why Consumers Misattribute Sponsorships to Non-Sponsor Brands: Differential Roles of Item and Relational Communications.

Science.gov (United States)

Weeks, Clinton S; Humphreys, Michael S; Cornwell, T Bettina

2018-02-01

Brands engaged in sponsorship of events commonly have objectives that depend on consumer memory for the sponsor-event relationship (e.g., sponsorship awareness). Consumers however, often misattribute sponsorships to nonsponsor competitor brands, indicating erroneous memory for these relationships. The current research uses an item and relational memory framework to reveal sponsor brands may inadvertently foster this misattribution when they communicate relational linkages to events. Effects can be explained via differential roles of communicating item information (information that supports processing item distinctiveness) versus relational information (information that supports processing relationships among items) in contributing to memory outcomes. Experiment 1 uses event-cued brand recall to show that correct memory retrieval is best supported by communicating relational information when sponsorship relationships are not obvious (low congruence). In contrast, correct retrieval is best supported by communicating item information when relationships are obvious (high congruence). Experiment 2 uses brand-cued event recall to show that, against conventional marketing recommendations, relational information increases misattribution, whereas item information guards against misattribution. Results suggest sponsor brands must distinguish between item and relational communications to enhance correct retrieval and limit misattribution. Methodologically, the work shows that choice of cueing direction is critical in differentially revealing patterns of correct and incorrect retrieval with pair relationships. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Item response theory analysis of Centers for Disease Control and Prevention Health-Related Quality of Life (CDC HRQOL) items in adults with arthritis.

Science.gov (United States)

Mielenz, Thelma J; Callahan, Leigh F; Edwards, Michael C

2016-03-12

Examine the feasibility of performing an item response theory (IRT) analysis on two of the Centers for Disease Control and Prevention health-related quality of life (CDC HRQOL) modules - the 4-item Healthy Days Core Module (HDCM) and the 5-item Healthy days Symptoms Module (HDSM). Previous principal components analyses confirm that the two scales both assess a mix of mental (CDC-MH) and physical health (CDC-PH). The purpose is to conduct item response theory (IRT) analysis on the CDC-MH and CDC-PH scales separately. 2182 patients with self-reported or physician-diagnosed arthritis completed a cross-sectional survey including HDCM and HDSM items. Besides global health, the other 8 items ask the number of days that some statement was true; we chose to recode the data into 8 categories based on observed clustering. The IRT assumptions were assessed using confirmatory factor analysis and the data could be modeled using an unidimensional IRT model. The graded response model was used for IRT analyses and CDC-MH and CDC-PH scales were analyzed separately in flexMIRT. The IRT parameter estimates for the five-item CDC-PH all appeared reasonable. The three-item CDC-MH did not have reasonable parameter estimates. The CDC-PH scale is amenable to IRT analysis but the existing The CDC-MH scale is not. We suggest either using the 4-item Healthy Days Core Module (HDCM) and the 5-item Healthy days Symptoms Module (HDSM) as they currently stand or the CDC-PH scale alone if the primary goal is to measure physical health related HRQOL.

Finding related functional neuroimaging volumes

DEFF Research Database (Denmark)

Nielsen, Finn Årup; Hansen, Lars Kai

2004-01-01

We describe a content-based image retrieval technique for finding related functional neuroimaging experiments by voxelization of sets of stereotactic coordinates in Talairach space, comparing the volumes and reporting related volumes in a sorted list. Voxelization is accomplished by convolving ea...

The processing of inter-item relations as a moderating factor of retrieval-induced forgetting

OpenAIRE

Tempel, Tobias; Wippich, Werner

2012-01-01

We investigated influences of item generation and emotional valence on retrieval-induced forgetting. Drawing on postulates of the three-factor theory of generation effects, generation tasks differentially affecting the processing of inter-item relations were applied. Whereas retrieval-induced forgetting of freely generated items was moderated by the emotional valence as well as retrieval-induced forgetting of read items, even though in the reverse direction (Experiment 1), fragment completion...

The Role of Item Models in Automatic Item Generation

Science.gov (United States)

Gierl, Mark J.; Lai, Hollis

2012-01-01

Automatic item generation represents a relatively new but rapidly evolving research area where cognitive and psychometric theories are used to produce tests that include items generated using computer technology. Automatic item generation requires two steps. First, test development specialists create item models, which are comparable to templates…

Item information and discrimination functions for trinary PCM items

NARCIS (Netherlands)

Akkermans, Wies; Muraki, Eiji

1997-01-01

For trinary partial credit items the shape of the item information and the item discrimination function is examined in relation to the item parameters. In particular, it is shown that these functions are unimodal if δ2 – δ1 < 4 ln 2 and bimodal otherwise. The locations and values of the maxima are

77 FR 75187 - Certain Food Containers, Cups, Plates, Cutlery, and Related Items and Packaging Thereof...

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2012-12-19

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-835] Certain Food Containers, Cups, Plates, Cutlery, and Related Items and Packaging Thereof; Commission Determination Not To Review an... containers, cups, plates, cutlery, and related items and packaging thereof by reason of infringement of U.S...

Memory in pregnancy and post-partum: Item specific and relational encoding processes in recall and recognition.

Science.gov (United States)

Spataro, Pietro; Saraulli, Daniele; Oriolo, Debora; Costanzi, Marco; Zanetti, Humberto; Cestari, Vincenzo; Rossi-Arnaud, Clelia

2016-08-01

It has been recently proposed that pregnant women would perform memory tasks by focusing more on item-specific processes and less on relational processing, compared to post-partum women (Mickes, Wixted, Shapiro & Scarff, ). The present cross-sectional study tested this hypothesis by directly manipulating the type of encoding employed in the study phase. Pregnant, post-partum and control women either rated the pleasantness of word meaning (which induced item-specific elaboration) or named the semantic category to which they belonged (which induced relational elaboration). Memory for the encoded words was later tested in free recall (which emphasizes relational processing) and in recognition (which emphasizes item-specific processing). In line with Mickes et al.'s () conclusions, pregnant women in the item-specific condition performed worse than post-partum women in the relational condition in free recall, but not in recognition. However, compared to the other two groups, pregnant women also exhibited lower recognition accuracy in the item-specific condition. Overall, these results confirm that pregnant women rely on relational encoding less than post-partum women, but additionally suggest that the former group might use item-specific processes less efficiently than post-partum and control women. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

DRD4 long allele carriers show heightened attention to high-priority items relative to low-priority items.

Science.gov (United States)

Gorlick, Marissa A; Worthy, Darrell A; Knopik, Valerie S; McGeary, John E; Beevers, Christopher G; Maddox, W Todd

2015-03-01

Humans with seven or more repeats in exon III of the DRD4 gene (long DRD4 carriers) sometimes demonstrate impaired attention, as seen in attention-deficit hyperactivity disorder, and at other times demonstrate heightened attention, as seen in addictive behavior. Although the clinical effects of DRD4 are the focus of much work, this gene may not necessarily serve as a "risk" gene for attentional deficits, but as a plasticity gene where attention is heightened for priority items in the environment and impaired for minor items. Here we examine the role of DRD4 in two tasks that benefit from selective attention to high-priority information. We examine a category learning task where performance is supported by focusing on features and updating verbal rules. Here, selective attention to the most salient features is associated with good performance. In addition, we examine the Operation Span (OSPAN) task, a working memory capacity task that relies on selective attention to update and maintain items in memory while also performing a secondary task. Long DRD4 carriers show superior performance relative to short DRD4 homozygotes (six or less tandem repeats) in both the category learning and OSPAN tasks. These results suggest that DRD4 may serve as a "plasticity" gene where individuals with the long allele show heightened selective attention to high-priority items in the environment, which can be beneficial in the appropriate context.

Commercial grade item (CGI) dedication of generators for nuclear safety related applications

International Nuclear Information System (INIS)

Das, R.K.; Hajos, L.G.

1993-01-01

The number of nuclear safety related equipment suppliers and the availability of spare and replacement parts designed specifically for nuclear safety related application are shrinking rapidly. These have made it necessary for utilities to apply commercial grade spare and replacement parts in nuclear safety related applications after implementing proper acceptance and dedication process to verify that such items conform with the requirements of their use in nuclear safety related application. The general guidelines for the commercial grade item (CGI) acceptance and dedication are provided in US Nuclear Regulatory Commission (NRC) Generic Letters and Electric Power Research Institute (EPRI) Report NP-5652, Guideline for the Utilization of Commercial Grade Items in Nuclear Safety Related Applications. This paper presents an application of these generic guidelines for procurement, acceptance, and dedication of a commercial grade generator for use as a standby generator at Salem Generating Station Units 1 and 2. The paper identifies the critical characteristics of the generator which once verified, will provide reasonable assurance that the generator will perform its intended safety function. The paper also delineates the method of verification of the critical characteristics through tests and provide acceptance criteria for the test results. The methodology presented in this paper may be used as specific guidelines for reliable and cost effective procurement and dedication of commercial grade generators for use as standby generators at nuclear power plants

Amygdala volume linked to individual differences in mental state inference in early childhood and adulthood

Directory of Open Access Journals (Sweden)

Katherine Rice

2014-04-01

Full Text Available We investigated the role of the amygdala in mental state inference in a sample of adults and in a sample of children aged 4 and 6 years. This period in early childhood represents a time when mentalizing abilities undergo dramatic changes. Both children and adults inferred mental states from pictures of others’ eyes, and children also inferred the mental states of others from stories (e.g., a false belief task. We also collected structural MRI data from these participants, to determine whether larger amygdala volumes (controlling for age and total gray matter volume were related to better face-based and story-based mentalizing. For children, larger amygdala volumes were related to better face-based, but not story-based, mentalizing. In contrast, in adults, amygdala volume was not related to face-based mentalizing. We next divided the face-based items into two subscales: cognitive (e.g., thinking, not believing versus affective (e.g., friendly, kind items. For children, performance on cognitive items was positively correlated with amygdala volume, but for adults, only performance on affective items was positively correlated with amygdala volume. These results indicate that the amygdala's role in mentalizing may be specific to face-based tasks and that the nature of its involvement may change over development.

77 FR 14423 - Certain Food Containers, Cups, Plates, Cutlery, and Related Items, and Packaging Thereof; Notice...

Science.gov (United States)

2012-03-09

... INTERNATIONAL TRADE COMMISSION [DN 2883] Certain Food Containers, Cups, Plates, Cutlery, and... Containers, Cups, Plates, Cutlery, and Related Items, and Packaging Thereof, DN 2883; the Commission is... importation of certain food containers, cups, plates, cutlery, and related items, and packaging thereof. The...

Few items in the thyroid-related quality of life instrument ThyPRO exhibited differential item functioning.

Science.gov (United States)

Watt, Torquil; Groenvold, Mogens; Hegedüs, Laszlo; Bonnema, Steen Joop; Rasmussen, Åse Krogh; Feldt-Rasmussen, Ulla; Bjorner, Jakob Bue

2014-02-01

To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis. A total of 838 patients with benign thyroid diseases completed the ThyPRO questionnaire (84 five-point items, 13 scales). Uniform and nonuniform DIF were investigated using ordinal logistic regression, testing for both statistical significance and magnitude (∆R(2) > 0.02). Scale level was estimated by the sum score, after purification. Twenty instances of DIF in 17 of the 84 items were found. Eight according to diagnosis, where the goiter scale was the one most affected, possibly due to differing perceptions in patients with auto-immune thyroid diseases compared to patients with simple goiter. Eight DIFs according to age were found, of which 5 were in positively worded items, which younger patients were more likely to endorse; one according to gender: women were more likely to report crying, and three according to educational level. The vast majority of DIF had only minor influence on the scale scores (0.1-2.3 points on the 0-100 scales), but two DIF corresponded to a difference of 4.6 and 9.8, respectively. Ordinal logistic regression identified DIF in 17 of 84 items. The potential impact of this on the present scales was low, but items displaying DIF could be avoided when developing abbreviated scales, where the potential impact of DIF (due to fewer items) will be larger.

Differential item functioning (DIF) analyses of health-related quality of life instruments using logistic regression

DEFF Research Database (Denmark)

Scott, Neil W.; Fayers, Peter M.; Aaronson, Neil K.

2010-01-01

Differential item functioning (DIF) methods can be used to determine whether different subgroups respond differently to particular items within a health-related quality of life (HRQoL) subscale, after allowing for overall subgroup differences in that scale. This article reviews issues that arise...

Benthic marine debris, with an emphasis on fishery-related items, surrounding Kodiak Island, Alaska, 1994-1996

Science.gov (United States)

Hess, N.A.; Ribic, C.A.; Vining, I.

1999-01-01

Composition and abundance of benthic marine debris were investigated during three bottom trawl surveys in inlet and offshore locations surrounding Kodiak Island, Alaska, 1994-1996. Debris items were primarily plastic and metal regardless of trawl location. Plastic bait jars, fishing line, and crab pots were the most common fishery-related debris items and were encountered in large amounts in inlets (20-25 items km-2), but were less abundant outside of inlets (4.5-11 items km-2). Overall density of debris was also significantly greater in inlets than outside of inlets. Plastic debris densities in inlets ranged 22-31.5 items km-2, 7.8-18.8 items km-2 outside of inlets. Trawls in inlets contained almost as much metal debris as plastic debris. Density of metal debris ranged from 21.2 to 23.7 items km-2 in inlets, a maximum of 2.7 items km-2 outside of inlets. Inlets around the town of Kodiak had the highest densities of fishery-related and total benthic debris. Differences in benthic debris density between inlets and outside of inlets and differences by area may be due to differences in fishing activity and water circulation patterns. At the current reduced levels of fishing activity, however, yearly monitoring of benthic debris appears unnecessary. Copyright (C) 1999.

Using an FSDS-R Item to Screen for Sexually Related Distress: A MsFLASH Analysis

Directory of Open Access Journals (Sweden)

Janet S. Carpenter, PhD, RN, FAAN

2015-03-01

Conclusions: A single FSDS-R item may be a useful screening tool to quickly identify midlife women with sexually related distress when it is not feasible to administer the entire scale, though further validation is warranted. Carpenter JS, Reed SD, Guthrie KA, Larson JC, Newton KM, Lau RJ, Learman LA, and Shifren JL. Using an FSDS-R item to screen for sexually related distress: A MsFLASH analysis. Sex Med 2015;3:7–13.

Memory deficit in patients with schizophrenia and posttraumatic stress disorder: relational vs item-specific memory

Directory of Open Access Journals (Sweden)

Jung W

2016-05-01

Full Text Available Wookyoung Jung,1 Seung-Hwan Lee1,2 1Clinical Emotions and Cognition Research Laboratory, Department of Psychiatry, Inje University, Ilsan-Paik Hospital, 2Department of Psychiatry, Inje University, Ilsan-Paik Hospital, Goyang, Korea Abstract: It has been well established that patients with schizophrenia have impairments in cognitive functioning and also that patients who experienced traumatic events suffer from cognitive deficits. Of the cognitive deficits revealed in schizophrenia or posttraumatic stress disorder (PTSD patients, the current article provides a brief review of deficit in episodic memory, which is highly predictive of patients’ quality of life and global functioning. In particular, we have focused on studies that compared relational and item-specific memory performance in schizophrenia and PTSD, because measures of relational and item-specific memory are considered the most promising constructs for immediate tangible development of clinical trial paradigm. The behavioral findings of schizophrenia are based on the tasks developed by the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS initiative and the Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia (CNTRACS Consortium. The findings we reviewed consistently showed that schizophrenia and PTSD are closely associated with more severe impairments in relational memory compared to item-specific memory. Candidate brain regions involved in relational memory impairment in schizophrenia and PTSD are also discussed. Keywords: schizophrenia, posttraumatic stress disorder, episodic memory deficit, relational memory, item-specific memory, prefrontal cortex, hippocampus

Evaluation of psychometric properties and differential item functioning of 8-item Child Perceptions Questionnaires using item response theory.

Science.gov (United States)

Yau, David T W; Wong, May C M; Lam, K F; McGrath, Colman

2015-08-19

Four-factor structure of the two 8-item short forms of Child Perceptions Questionnaire CPQ11-14 (RSF:8 and ISF:8) has been confirmed. However, the sum scores are typically reported in practice as a proxy of Oral health-related Quality of Life (OHRQoL), which implied a unidimensional structure. This study first assessed the unidimensionality of 8-item short forms of CPQ11-14. Item response theory (IRT) was employed to offer an alternative and complementary approach of validation and to overcome the limitations of classical test theory assumptions. A random sample of 649 12-year-old school children in Hong Kong was analyzed. Unidimensionality of the scale was tested by confirmatory factor analysis (CFA), principle component analysis (PCA) and local dependency (LD) statistic. Graded response model was fitted to the data. Contribution of each item to the scale was assessed by item information function (IIF). Reliability of the scale was assessed by test information function (TIF). Differential item functioning (DIF) across gender was identified by Wald test and expected score functions. Both CPQ11-14 RSF:8 and ISF:8 did not deviate much from the unidimensionality assumption. Results from CFA indicated acceptable fit of the one-factor model. PCA indicated that the first principle component explained >30 % of the total variation with high factor loadings for both RSF:8 and ISF:8. Almost all LD statistic items suggesting little contribution of information to the scale and item removal caused little practical impact. Comparing the TIFs, RSF:8 showed slightly better information than ISF:8. In addition to oral symptoms items, the item "Concerned with what other people think" demonstrated a uniform DIF (p Items related to oral symptoms were not informative to OHRQoL and deletion of these items is suggested. The impact of DIF across gender on the overall score was minimal. CPQ11-14 RSF:8 performed slightly better than ISF:8 in measurement precision. The 6-item short forms

The measurement of cyberbullying: dimensional structure and relative item severity and discrimination.

Science.gov (United States)

Menesini, Ersilia; Nocentini, Annalaura; Calussi, Pamela

2011-05-01

In relation to a sample of 1,092 Italian adolescents (50.9% females), the present study aims to: (a) analyze the most parsimonious structure of the cyberbullying and cybervictimization construct in male and female Italian adolescents through confirmatory factor analysis; and (b) analyze the severity and the discrimination parameters of each act using the item response theory. Results showed that the structure of the cyberbullying scale for perpetrated and received behaviors in both genders could best be represented by a monodimensional model where each item lies on a continuum of severity of aggressive acts. For both genders, the less severe acts are silent/prank calls and insults on instant messaging, and the most severe acts are unpleasant pictures/photos on Web sites, phone pictures/photos/videos of intimate scenes, and phone pictures/photos/videos of violent scenes. The items nasty text messages, nasty or rude e-mails, insults on Web sites, insults in chatrooms, and insults on blogs range from moderate to high levels of severity. Regarding the discrimination level of the acts, several items emerged as good indicators at various levels of cyberbullying and cybervictimization severity, with the exception of silent/prank calls. Furthermore, gender specificities underlined that the visual items can be considered good indicators of severe cyberbullies and cybervictims only in males. This information can help in understanding better the nature of the phenomenon, its severity in a given population, and to plan more specific prevention and intervention strategies.

On pressure: volume relations in hemodialysis

NARCIS (Netherlands)

E.H.Y. Ie (Eric)

2005-01-01

textabstractChapter 1 is a brief introduction to several aspects of cardiovascular pressure-volume relations in dialysis patients. The aims of the thesis are presented. In Chapter 2, an overview is presented of circulatory physiology in hemodialysis (HD) patients. Volume withdrawal by

Management plan documentation standard and Data Item Descriptions (DID). Volume of the information system life-cycle and documentation standards, volume 2

Science.gov (United States)

Callender, E. David; Steinbacher, Jody

1989-01-01

This is the second of five volumes of the Information System Life-Cycle and Documentation Standards. This volume provides a well-organized, easily used standard for management plans used in acquiring, assuring, and developing information systems and software, hardware, and operational procedures components, and related processes.

Improving Measurement Efficiency of the Inner EAR Scale with Item Response Theory.

Science.gov (United States)

Jessen, Annika; Ho, Andrew D; Corrales, C Eduardo; Yueh, Bevan; Shin, Jennifer J

2018-02-01

Objectives (1) To assess the 11-item Inner Effectiveness of Auditory Rehabilitation (Inner EAR) instrument with item response theory (IRT). (2) To determine whether the underlying latent ability could also be accurately represented by a subset of the items for use in high-volume clinical scenarios. (3) To determine whether the Inner EAR instrument correlates with pure tone thresholds and word recognition scores. Design IRT evaluation of prospective cohort data. Setting Tertiary care academic ambulatory otolaryngology clinic. Subjects and Methods Modern psychometric methods, including factor analysis and IRT, were used to assess unidimensionality and item properties. Regression methods were used to assess prediction of word recognition and pure tone audiometry scores. Results The Inner EAR scale is unidimensional, and items varied in their location and information. Information parameter estimates ranged from 1.63 to 4.52, with higher values indicating more useful items. The IRT model provided a basis for identifying 2 sets of items with relatively lower information parameters. Item information functions demonstrated which items added insubstantial value over and above other items and were removed in stages, creating a 8- and 3-item Inner EAR scale for more efficient assessment. The 8-item version accurately reflected the underlying construct. All versions correlated moderately with word recognition scores and pure tone averages. Conclusion The 11-, 8-, and 3-item versions of the Inner EAR scale have strong psychometric properties, and there is correlational validity evidence for the observed scores. Modern psychometric methods can help streamline care delivery by maximizing relevant information per item administered.

Validation of the PROMIS Sleep Disturbance and Sleep-Related Impairment item banks in Dutch adolescents.

Science.gov (United States)

van Kooten, Jojanneke A M C; van Litsenburg, Raphaёle R L; Yoder, Whitney R; Kaspers, Gertjan J L; Terwee, Caroline B

2018-04-16

Sleep problems are common in adolescents and have a negative impact on daytime functioning. However, there is a lack of well-validated adolescent sleep questionnaires. The Patient-Reported Outcomes Measurement Information System (PROMIS) Sleep Disturbance and Sleep-Related Impairment item banks are well-validated instruments developed for and tested in adults. The aim of this study was to evaluate their structural validity in adolescents. Test and retest data were collected for the Dutch-Flemish V1.0 PROMIS Sleep Disturbance (27) and Sleep-Related Impairment (16 items) item banks from 1046 adolescents (11-19 years). Cross-validation methods, Confirmatory (CFA), and Exploratory Factor Analyses (EFA) were used. Fit indices and factor loadings were used to improve the models. The final models were assessed for model fit using retest data. The one-factor Sleep Disturbance (CFI = 0.795, TLI = 0.778, RMSEA = 0.117) and Sleep-Related Impairment (CFI = 0.897, TLI = 0.882, RMSEA = 0.156) models could not be replicated in adolescents. Cross-validation resulted in a final Sleep Disturbance model of 23 and a Sleep-Related Impairment model of 11 items. Retest data CFA showed adequate fit for the Sleep-Related Impairment-11 (CFI = 0.981, TLI = 0.976, RMSEA = 0.116). The Sleep Disturbance-23 model fit indices stayed below the recommended values (CFI = 0.895, TLI = 0.885, RMSEA = 0.105). While the PROMIS Sleep Disturbance-23 for adolescents and PROMIS Sleep-Related Impairment-11 for adolescents provide a framework to assess adolescent sleep, additional research is needed to replicate these findings in a larger and more diverse sample.

The Role of Medial Temporal Lobe Regions in Incidental and Intentional Retrieval of Item and Relational Information in Aging.

Science.gov (United States)

Wang, Wei-Chun; Giovanello, Kelly S

2016-06-01

Considerable neuropsychological and neuroimaging work indicates that the medial temporal lobes are critical for both item and relational memory retrieval. However, there remain outstanding issues in the literature, namely the extent to which medial temporal lobe regions are differentially recruited during incidental and intentional retrieval of item and relational information, and the extent to which aging may affect these neural substrates. The current fMRI study sought to address these questions; participants incidentally encoded word pairs embedded in sentences and incidental item and relational retrieval were assessed through speeded reading of intact, rearranged, and new word-pair sentences, while intentional item and relational retrieval were assessed through old/new associative recognition of a separate set of intact, rearranged, and new word pairs. Results indicated that, in both younger and older adults, anterior hippocampus and perirhinal cortex indexed incidental and intentional item retrieval in the same manner. In contrast, posterior hippocampus supported incidental and intentional relational retrieval in both age groups and an adjacent cluster in posterior hippocampus was recruited during both forms of relational retrieval for older, but not younger, adults. Our findings suggest that while medial temporal lobe regions do not differentiate between incidental and intentional forms of retrieval, there are distinct roles for anterior and posterior medial temporal lobe regions during retrieval of item and relational information, respectively, and further indicate that posterior regions may, under certain conditions, be over-recruited in healthy aging. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The practical impact of differential item functioning analyses in a health-related quality of life instrument

DEFF Research Database (Denmark)

Scott, Neil W; Fayers, Peter M; Aaronson, Neil K

2009-01-01

Differential item functioning (DIF) analyses are commonly used to evaluate health-related quality of life (HRQoL) instruments. There is, however, a lack of consensus as to how to assess the practical impact of statistically significant DIF results.......Differential item functioning (DIF) analyses are commonly used to evaluate health-related quality of life (HRQoL) instruments. There is, however, a lack of consensus as to how to assess the practical impact of statistically significant DIF results....

Problems with the factor analysis of items: Solutions based on item response theory and item parcelling

Directory of Open Access Journals (Sweden)

Gideon P. De Bruin

2004-10-01

Full Text Available The factor analysis of items often produces spurious results in the sense that unidimensional scales appear multidimensional. This may be ascribed to failure in meeting the assumptions of linearity and normality on which factor analysis is based. Item response theory is explicitly designed for the modelling of the non-linear relations between ordinal variables and provides a strong alternative to the factor analysis of items. Items may also be combined in parcels that are more likely to satisfy the assumptions of factor analysis than do the items. The use of the Rasch rating scale model and the factor analysis of parcels is illustrated with data obtained with the Locus of Control Inventory. The results of these analyses are compared with the results obtained through the factor analysis of items. It is shown that the Rasch rating scale model and the factoring of parcels produce superior results to the factor analysis of items. Recommendations for the analysis of scales are made. Opsomming Die faktorontleding van items lewer dikwels misleidende resultate op, veral in die opsig dat eendimensionele skale as meerdimensioneel voorkom. Hierdie resultate kan dikwels daaraan toegeskryf word dat daar nie aan die aannames van lineariteit en normaliteit waarop faktorontleding berus, voldoen word nie. Itemresponsteorie, wat eksplisiet vir die modellering van die nie-liniêre verbande tussen ordinale items ontwerp is, bied ’n aantreklike alternatief vir die faktorontleding van items. Items kan ook in pakkies gegroepeer word wat meer waarskynlik aan die aannames van faktorontleding voldoen as individuele items. Die gebruik van die Rasch beoordelingskaalmodel en die faktorontleding van pakkies word aan die hand van data wat met die Lokus van Beheervraelys verkry is, gedemonstreer. Die resultate van hierdie ontledings word vergelyk met die resultate wat deur ‘n faktorontleding van die individuele items verkry is. Die resultate dui daarop dat die Rasch

Characterization of radioactive waste forms. Volume 1

International Nuclear Information System (INIS)

Brodersen, K.; Nilsson, K.

1989-01-01

This document is the second yearbook for Task 3 of the European Communities 1985-89 programme of research on radioactive waste management and disposal carried out by public organizations and private firms in the Community through costsharing contracts with the Commission of the European Communities. The report, in two volumes, describes progress made in 1987 within the field of Task 3: Testing and evaluation of conditioned waste and engineered barriers. The first volume of the report covers Item 3.1 Characterization of low and medium-level radioactive waste forms and Item 3.5 Development of test methods for quality assurance. The second volume covers Item 3.2: High-level and alpha waste characterization and Item 3.3: Other engineered barriers. Item 3.4 on the round robin study will be treated in a separate report

Few items in the thyroid-related quality of life instrument ThyPRO exhibited differential item functioning

DEFF Research Database (Denmark)

Watt, Torquil; Grønvold, Mogens; Hegedüs, Laszlo

2014-01-01

To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis.......To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis....

Re-evaluating a vision-related quality of life questionnaire with item response theory (IRT and differential item functioning (DIF analyses

Directory of Open Access Journals (Sweden)

Knol Dirk L

2011-09-01

Full Text Available Abstract Background For the Low Vision Quality Of Life questionnaire (LVQOL it is unknown whether the psychometric properties are satisfactory when an item response theory (IRT perspective is considered. This study evaluates some essential psychometric properties of the LVQOL questionnaire in an IRT model, and investigates differential item functioning (DIF. Methods Cross-sectional data were used from an observational study among visually-impaired patients (n = 296. Calibration was performed for every dimension of the LVQOL in the graded response model. Item goodness-of-fit was assessed with the S-X2-test. DIF was assessed on relevant background variables (i.e. age, gender, visual acuity, eye condition, rehabilitation type and administration type with likelihood-ratio tests for DIF. The magnitude of DIF was interpreted by assessing the largest difference in expected scores between subgroups. Measurement precision was assessed by presenting test information curves; reliability with the index of subject separation. Results All items of the LVQOL dimensions fitted the model. There was significant DIF on several items. For two items the maximum difference between expected scores exceeded one point, and DIF was found on multiple relevant background variables. Item 1 'Vision in general' from the "Adjustment" dimension and item 24 'Using tools' from the "Reading and fine work" dimension were removed. Test information was highest for the "Reading and fine work" dimension. Indices for subject separation ranged from 0.83 to 0.94. Conclusions The items of the LVQOL showed satisfactory item fit to the graded response model; however, two items were removed because of DIF. The adapted LVQOL with 21 items is DIF-free and therefore seems highly appropriate for use in heterogeneous populations of visually impaired patients.

Computerized Adaptive Test (CAT) Applications and Item Response Theory Models for Polytomous Items

Science.gov (United States)

Aybek, Eren Can; Demirtasli, R. Nukhet

2017-01-01

This article aims to provide a theoretical framework for computerized adaptive tests (CAT) and item response theory models for polytomous items. Besides that, it aims to introduce the simulation and live CAT software to the related researchers. Computerized adaptive test algorithm, assumptions of item response theory models, nominal response…

Differential item functioning (DIF) analyses of health-related quality of life instruments using logistic regression

DEFF Research Database (Denmark)

Scott, Neil W; Fayers, Peter M; Aaronson, Neil K

2010-01-01

Differential item functioning (DIF) methods can be used to determine whether different subgroups respond differently to particular items within a health-related quality of life (HRQoL) subscale, after allowing for overall subgroup differences in that scale. This article reviews issues that arise ...... when testing for DIF in HRQoL instruments. We focus on logistic regression methods, which are often used because of their efficiency, simplicity and ease of application....

The Relative Importance of Persons, Items, Subtests, and Languages to TOEFL Test Variance.

Science.gov (United States)

Brown, James Dean

1999-01-01

Explored the relative contributions to Test of English as a Foreign Language (TOEFL) score dependability of various numbers of persons, items, subtests, languages, and their various interactions. Sampled 15,000 test takers, 1000 each from 15 different language backgrounds. (Author/VWL)

Characterization of radioactive waste forms. Volume 2

International Nuclear Information System (INIS)

Smith, D.L.; Green, T.H.

1989-01-01

This document is the second yearbook for Task 3 of the European Communities 1985-89 programme of research on radioactive waste management and disposal carried out by public organizations and private firms in the Community through cost-sharing contracts with the Commission of the European Communities. The report, in two volumes, describes progress made in 1987 within the field of Task 3: Testing and evaluation of conditioned waste and engineered barriers. The first volume of the report covers Item 3.1 Characterization of low and medium level radioactive waste forms and Item 3.5. Development of test methods for quality assurance. The second volume covers Item 3.2: High-level and alpha waste characterization and Item 3.3: Other engineered barriers. Item 3.4 on the round robin study will be treated in a separate report

Application of the Commercial Grade Item (CGI) Dedication Process for Procurement of Nuclear Safety Related Items at Nuclear Power Plant Krsko (NEK)

International Nuclear Information System (INIS)

Heruc, Z.; Pozar, J.

1998-01-01

CGI procurement is a process whereby parts are brought without imposing Appendix B Quality Assurance requirements on the supplier, and than dedicated for use in safety-related applications. The dedication process involves 1) based upon required safety function, an engineering evaluation to identify critical characteristic of the item and specification of acceptance criteria; and 2) quality control activities to ensure the item(s) supplied meets the acceptance criteria specified. CGI Dedication supports the supply of certified components/parts for the plant operation in an environment where the number of nuclear qualified suppliers diminishes. It requires a more active role of the plant personnel, therefore presenting an additional burden on human resources, but at the same time increases the technical KNOW-HOW and improves the confidence of test and inspection data presented in the certificates. Very often it is also cost beneficial. This paper is a continuation to last year presentation of the introduction of this method into NEK's procurement process and presents the current approach and some practical examples. (author)

Spare Items validation

International Nuclear Information System (INIS)

Fernandez Carratala, L.

1998-01-01

There is an increasing difficulty for purchasing safety related spare items, with certifications by manufacturers for maintaining the original qualifications of the equipment of destination. The main reasons are, on the top of the logical evolution of technology, applied to the new manufactured components, the quitting of nuclear specific production lines and the evolution of manufacturers quality systems, originally based on nuclear codes and standards, to conventional industry standards. To face this problem, for many years different Dedication processes have been implemented to verify whether a commercial grade element is acceptable to be used in safety related applications. In the same way, due to our particular position regarding the spare part supplies, mainly from markets others than the american, C.N. Trillo has developed a methodology called Spare Items Validation. This methodology, which is originally based on dedication processes, is not a single process but a group of coordinated processes involving engineering, quality and management activities. These are to be performed on the spare item itself, its design control, its fabrication and its supply for allowing its use in destinations with specific requirements. The scope of application is not only focussed on safety related items, but also to complex design, high cost or plant reliability related components. The implementation in C.N. Trillo has been mainly curried out by merging, modifying and making the most of processes and activities which were already being performed in the company. (Author)

Australian Biology Test Item Bank, Years 11 and 12. Volume II: Year 12.

Science.gov (United States)

Brown, David W., Ed.; Sewell, Jeffrey J., Ed.

This document consists of test items which are applicable to biology courses throughout Australia (irrespective of course materials used); assess key concepts within course statement (for both core and optional studies); assess a wide range of cognitive processes; and are relevant to current biological concepts. These items are arranged under…

Australian Biology Test Item Bank, Years 11 and 12. Volume I: Year 11.

Science.gov (United States)

Brown, David W., Ed.; Sewell, Jeffrey J., Ed.

This document consists of test items which are applicable to biology courses throughout Australia (irrespective of course materials used); assess key concepts within course statement (for both core and optional studies); assess a wide range of cognitive processes; and are relevant to current biological concepts. These items are arranged under…

Effect of high and low ultrafiltration volume during hemodialysis on relative blood volume

NARCIS (Netherlands)

Dasselaar, JJ; de Jong, PE; Huisman, RM; Franssen, CFM

2006-01-01

Achieving an optimal posthemodialysis hydration status may be difficult because objective criteria for dry weight are lacking. Both relative blood volume changes (Delta RBV) at the end of hemodialysis and Delta RBV normalized for ultrafiltration volume (Delta RBV/UF ratio) have been reported to

The role of attention in item-item binding in visual working memory.

Science.gov (United States)

Peterson, Dwight J; Naveh-Benjamin, Moshe

2017-09-01

An important yet unresolved question regarding visual working memory (VWM) relates to whether or not binding processes within VWM require additional attentional resources compared with processing solely the individual components comprising these bindings. Previous findings indicate that binding of surface features (e.g., colored shapes) within VWM is not demanding of resources beyond what is required for single features. However, it is possible that other types of binding, such as the binding of complex, distinct items (e.g., faces and scenes), in VWM may require additional resources. In 3 experiments, we examined VWM item-item binding performance under no load, articulatory suppression, and backward counting using a modified change detection task. Binding performance declined to a greater extent than single-item performance under higher compared with lower levels of concurrent load. The findings from each of these experiments indicate that processing item-item bindings within VWM requires a greater amount of attentional resources compared with single items. These findings also highlight an important distinction between the role of attention in item-item binding within VWM and previous studies of long-term memory (LTM) where declines in single-item and binding test performance are similar under divided attention. The current findings provide novel evidence that the specific type of binding is an important determining factor regarding whether or not VWM binding processes require attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Item-focussed Trees for the Identification of Items in Differential Item Functioning.

Science.gov (United States)

Tutz, Gerhard; Berger, Moritz

2016-09-01

A novel method for the identification of differential item functioning (DIF) by means of recursive partitioning techniques is proposed. We assume an extension of the Rasch model that allows for DIF being induced by an arbitrary number of covariates for each item. Recursive partitioning on the item level results in one tree for each item and leads to simultaneous selection of items and variables that induce DIF. For each item, it is possible to detect groups of subjects with different item difficulties, defined by combinations of characteristics that are not pre-specified. The way a DIF item is determined by covariates is visualized in a small tree and therefore easily accessible. An algorithm is proposed that is based on permutation tests. Various simulation studies, including the comparison with traditional approaches to identify items with DIF, show the applicability and the competitive performance of the method. Two applications illustrate the usefulness and the advantages of the new method.

Analysis of end-systolic pressure-volume relation by gated radionuclide angiocardiography

International Nuclear Information System (INIS)

Adachi, Haruhiko; Sugihara, Horoki; Katsume, Hiroshi; Ijichi, Hamao; Miyanaga, Hajime

1982-01-01

Left ventricular end-systolic pressure-volume relation has been proved experimentally to b e an useful index of left ventricular contractility relatively independent of preload or afterload. But less clinical application has been reported because of its invasive nature, and we evaluated this relationship non-invasively using gated radionuclide angiocardiography as volume determination and cuff sphyngomanometer in the arm as pressure measurement. Gated equilibrium blood pool scintigrams were obtained at rest and during intravenous infusion of angiotensin or nitrate. Ventricular volumes were derived from ventricular activity and peripheral blood volume and activity. The peak systolic pressure (PSP) by cuff method to end-systolic volume index (ESVI) relations showed good linearity (r gt .930 in 84% of consecutive 50 cases) and were gentler in the groups with more impaired left ventricular function. Emax was related exponentially to ejection fraction (EF) and hyperbolically to end-diastolic volume index. The dead volume (VoI) was unfixed and fell into positive or negative value, and was not related to EF under control condition. PSP/ESVI in each loading condition was less variable with the alteration of blood pressure than EF. The linear relation was found between PSP/ESVI under control condition and Emax (PSP/ESVI = 0.651.Emax + 0.958, r = 0.841, p lt .001). Thus in measuring ventricular volume, gated radionuclide angiocardiography is a non-invasive method less affected by the geometry of the left ventricle. Non-invasive determination of end-systolic pressure-volume relation using the volume by radionuclide and the blood pressure by cuff method is clinically useful in the assessment of left ventricular contractility. (author)

Screening for HIV-related PTSD: sensitivity and specificity of the 17-item Posttraumatic Stress Diagnostic Scale (PDS) in identifying HIV-related PTSD among a South African sample.

Science.gov (United States)

Martin, L; Fincham, D; Kagee, A

2009-11-01

The identification of HIV-positive patients who exhibit criteria for Posttraumatic Stress Disorder (PTSD) and related trauma symptomatology is of clinical importance in the maintenance of their overall wellbeing. This study assessed the sensitivity and specificity of the 17-item Posttraumatic Stress Diagnostic Scale (PDS), a self-report instrument, in the detection of HIV-related PTSD. An adapted version of the PTSD module of the Composite International Diagnostic Interview (CIDI) served as the gold standard. 85 HIV-positive patients diagnosed with HIV within the year preceding data collection were recruited by means of convenience sampling from three HIV clinics within primary health care facilities in the Boland region of South Africa. A significant association was found between the 17-item PDS and the adapted PTSD module of the CIDI. A ROC curve analysis indicated that the 17-item PDS correctly discriminated between PTSD caseness and non-caseness 74.9% of the time. Moreover, a PDS cut-off point of > or = 15 yielded adequate sensitivity (68%) and 1-specificity (65%). The 17-item PDS demonstrated a PPV of 76.0% and a NPV of 56.7%. The 17-item PDS can be used as a brief screening measure for the detection of HIV-related PTSD among HIV-positive patients in South Africa.

Management control and status reports documentation standard and Data Item Descriptions (DID). Volume of the information system life-cycle and documentation standards, volume 5

Science.gov (United States)

Callender, E. David; Steinbacher, Jody

1989-01-01

This is the fifth of five volumes on Information System Life-Cycle and Documentation Standards. This volume provides a well organized, easily used standard for management control and status reports used in monitoring and controlling the management, development, and assurance of informations systems and software, hardware, and operational procedures components, and related processes.

Sharing the cost of redundant items

DEFF Research Database (Denmark)

Hougaard, Jens Leth; Moulin, Hervé

2014-01-01

We ask how to share the cost of finitely many public goods (items) among users with different needs: some smaller subsets of items are enough to serve the needs of each user, yet the cost of all items must be covered, even if this entails inefficiently paying for redundant items. Typical examples...... are network connectivity problems when an existing (possibly inefficient) network must be maintained. We axiomatize a family cost ratios based on simple liability indices, one for each agent and for each item, measuring the relative worth of this item across agents, and generating cost allocation rules...... additive in costs....

Factorial Structure and Age-Related Psychometrics of the MIDUS Personality Adjective Items across the Lifespan

Science.gov (United States)

Zimprich, Daniel; Allemand, Mathias; Lachman, Margie E.

2014-01-01

The present study addresses issues of measurement invariance and comparability of factor parameters of Big Five personality adjective items across age. Data from the Midlife in the United States (MIDUS) survey were used to investigate age-related developmental psychometrics of the MIDUS personality adjective items in two large cross-sectional samples (exploratory sample: N = 862; analysis sample: N = 3,000). After having established and replicated a comprehensive five-factor structure of the measure, increasing levels of measurement invariance were tested across ten age groups. Results indicate that the measure demonstrates strict measurement invariance in terms of number of factors and factor loadings. Also, we found that factor variances and covariances were equal across age groups. By contrast, a number of age-related factor mean differences emerged. The practical implications of these results are discussed and future research is suggested. PMID:21910548

Thermodynamic volume and the extended Smarr relation

Energy Technology Data Exchange (ETDEWEB)

Hyun, Seungjoon; Jeong, Jaehoon; Park, Sang-A; Yi, Sang-Heon [Department of Physics, College of Science, Yonsei University,Seoul 120-749 (Korea, Republic of)

2017-04-10

We continue to explore the scaling transformation in the reduced action formalism of gravity models. As an extension of our construction, we consider the extended forms of the Smarr relation for various black holes, adopting the cosmological constant as the bulk pressure as in some literatures on black holes. Firstly, by using the quasi-local formalism for charges, we show that, in a general theory of gravity, the volume in the black hole thermodynamics could be defined as the thermodynamic conjugate variable to the bulk pressure in such a way that the first law can be extended consistently. This, so called, thermodynamic volume can be expressed explicitly in terms of the metric and field variables. Then, by using the scaling transformation allowed in the reduced action formulation, we obtain the extended Smarr relation involving the bulk pressure and the thermodynamic volume. In our approach, we do not resort to Euler’s homogeneous scaling of charges while incorporating the would-be hairy contribution without any difficulty.

Development and Validation of a Novel Generic Health-related Quality of Life Instrument With 20 Items (HINT-20

Directory of Open Access Journals (Sweden)

Min-Woo Jo

2017-01-01

Full Text Available Objectives Few attempts have been made to develop a generic health-related quality of life (HRQoL instrument and to examine its validity and reliability in Korea. We aimed to do this in our present study. Methods After a literature review of existing generic HRQoL instruments, a focus group discussion, in-depth interviews, and expert consultations, we selected 30 tentative items for a new HRQoL measure. These items were evaluated by assessing their ceiling effects, difficulty, and redundancy in the first survey. To validate the HRQoL instrument that was developed, known-groups validity and convergent/discriminant validity were evaluated and its test-retest reliability was examined in the second survey. Results Of the 30 items originally assessed for the HRQoL instrument, four were excluded due to high ceiling effects and six were removed due to redundancy. We ultimately developed a HRQoL instrument with a reduced number of 20 items, known as the Health-related Quality of Life Instrument with 20 items (HINT-20, incorporating physical, mental, social, and positive health dimensions. The results of the HINT-20 for known-groups validity were poorer in women, the elderly, and those with a low income. For convergent/discriminant validity, the correlation coefficients of items (except vitality in the physical health dimension with the physical component summary of the Short Form 36 version 2 (SF-36v2 were generally higher than the correlations of those items with the mental component summary of the SF-36v2, and vice versa. Regarding test-retest reliability, the intraclass correlation coefficient of the total HINT-20 score was 0.813 (p<0.001. Conclusions A novel generic HRQoL instrument, the HINT-20, was developed for the Korean general population and showed acceptable validity and reliability.

Loglinear multidimensional IRT models for polytomously scired Items

NARCIS (Netherlands)

Kelderman, Henk

1988-01-01

A loglinear item response theory (IRT) model is proposed that relates polytomously scored item responses to a multidimensional latent space. Each item may have a different response function where each item response may be explained by one or more latent traits. Item response functions may follow a

Location Indices for Ordinal Polytomous Items Based on Item Response Theory. Research Report. ETS RR-15-20

Science.gov (United States)

Ali, Usama S.; Chang, Hua-Hua; Anderson, Carolyn J.

2015-01-01

Polytomous items are typically described by multiple category-related parameters; situations, however, arise in which a single index is needed to describe an item's location along a latent trait continuum. Situations in which a single index would be needed include item selection in computerized adaptive testing or test assembly. Therefore single…

Cleaning and disinfection of patient care items, in relation to small animals.

Science.gov (United States)

Weese, J Scott

2015-03-01

Patient care involves several medical and surgical items, including those that come into contact with sterile or other high-risk body sites and items that have been used on other patients. These situations create a risk for infection if items are contaminated, and the implications can range from single infections to large outbreaks. To minimize the risk, proper equipment cleaning, disinfection/sterilization, storage, and monitoring practices are required. Risks posed by different items; the required level of cleaning, disinfection, or sterilization; the methods that are available and appropriate; and how to ensure efficacy, must be considered when designing and implementing an infection control program. Copyright © 2015 Elsevier Inc. All rights reserved.

Relative blood volume changes underestimate total blood volume changes during hemodialysis

NARCIS (Netherlands)

Dasselaar, Judith J.; Lub-de Hooge, Marjolijn N.; Pruim, Jan; Nijnuis, Hugo; Wiersum, Anneke; de Jong, Paul E.; Huisman, Roel M.; Franssen, Casper F. M.

Background: Measurements of relative blood volume changes (ARBV) during hemodialysis (HD) are based on hemoconcentration and assume uniform mixing of erythrocytes and plasma throughout the circulation. However, whole-body hematocrit (Ht) is lower than systemic Ht. During HD, a change in the ratio

Encyclopedia of Explosives and Related Items. Volume 9

Science.gov (United States)

1980-01-01

NA), HNO. In the method used before WWII, NA was prepd Ammontol. A castable HE mixt of AN 50, by heating Na nitrate ( Chile saltpeter) with TNT 38...as an igniting charge in Pb Azide detonators Torpedos. Accdg to Gonzilez (Ref 11, p 76), torpedos can be used on land (tierra) or in water (en el agua ...sumergidos (Tetryl). Described in Ref 6, p 294; Ref 9, pp en agua ) after being waterproofed 21 & 139; and Ref 19, p 335. Lt-yel crysts; d 1.73g/cc

Encyclopedia of Explosives and Related Items. Volume 6

Science.gov (United States)

1974-01-01

TNT, NS, or smokeless powder , perhpas a soluble organic fuel such.as sugar, urea glycol, and frequently a natural gum thick- Explosives Sensitivity...detonation of solid expls) TNT, and thickened with guar gum , sodium 71) L. Deffet, Explosifs 13, 103 (1960) and CMC or sodium alginate) Explosivstoffe 12...The most common agent tartrate were effective) is a gum , such as guar gum . The gelling 95) Y. Matsuguma et al, KogyoKayaku 33(4), agent serves two

Encyclopedia of Explosives and Related Items. Volume 8

Science.gov (United States)

1978-01-01

samples containing a max of 0.5% w Ibid, E170 (Electrolytic Hygrometer Method); Neutron Measurements. The interaction of Ibid, E171 -L to E172-L...serving as blanks, and with a Element Matrix a Calculated Thermalc Fastd standard sample of TiO2 . Irradiations were Al At20 3 52.91 52.10 ±0.3 3e...concerns lead used include: MgO, TiO2 , Sr2 0 3 , ZnO, BaO, monoxide in its reaction with silicon while both Sb 2 03, Ta2 O5, W03 , U20 5 and HfO2 . Also

Encyclopedia of Explosives and Related Items. Volume 10

Science.gov (United States)

1983-01-01

SBR 75 Nylon 130 Polyvinyl Chloride 85 Polyethylene 80 160 Polyvinyl Acetate 75 Teflon FEP, TFE 160 160 Furan Resin 75 Phenolic Resin ___75. Kel-F 300...0 6706>Zo> 1372 pp ’np/W1/3 (s/kg1/3 ) 1.499 -5/6 0 4267>Z 0 >198 Tbpp/Wi/(s/kg1/ 3 ) 0.532 -5/6 0 1372>Z 0>198 bpp /W"/(s/kg/ 3) 0.099 -3/5 0 6706>Z0

Item validity vs. item discrimination index: a redundancy?

Science.gov (United States)

Panjaitan, R. L.; Irawati, R.; Sujana, A.; Hanifah, N.; Djuanda, D.

2018-03-01

In several literatures about evaluation and test analysis, it is common to find that there are calculations of item validity as well as item discrimination index (D) with different formula for each. Meanwhile, other resources said that item discrimination index could be obtained by calculating the correlation between the testee’s score in a particular item and the testee’s score on the overall test, which is actually the same concept as item validity. Some research reports, especially undergraduate theses tend to include both item validity and item discrimination index in the instrument analysis. It seems that these concepts might overlap for both reflect the test quality on measuring the examinees’ ability. In this paper, examples of some results of data processing on item validity and item discrimination index were compared. It would be discussed whether item validity and item discrimination index can be represented by one of them only or it should be better to present both calculations for simple test analysis, especially in undergraduate theses where test analyses were included.

Solid Waste Operations Complex W-113, Detail Design Report (Title II). Volume 3: Specifications

International Nuclear Information System (INIS)

1995-09-01

The Solid Waste Retrieval Facility--Phase 1 (Project W113) will provide the infrastructure and the facility required to retrieve from Trench 04, Burial ground 4C, contact handled (CH) drums and boxes at a rate that supports all retrieved TRU waste batching, treatment, storage, and disposal plans. This includes (1) operations related equipment and facilities, viz., a weather enclosure for the trench, retrieval equipment, weighing, venting, obtaining gas samples, overpacking, NDE, NDA, shipment of waste and (2) operations support related facilities, viz., a general office building, a retrieval staff change facility, and infrastructure upgrades such as supply and routing of water, sewer, electrical power, fire protection, roads, and telecommunication. Title I design for the operations related equipment and facilities was performed by Raytheon/BNFL, and that for the operations support related facilities including infrastructure upgrade was performed by KEH. These two scopes were combined into an integrated W113 Title II scope that was performed by Raytheon/BNFL. Volume 3 is a compilation of the construction specifications that will constitute the Title II materials and performance specifications. This volume contains CSI specifications for non-equipment related construction material type items, performance type items, and facility mechanical equipment items. Data sheets are provided, as necessary, which specify the equipment overall design parameters

Solid Waste Operations Complex W-113, Detail Design Report (Title II). Volume 3: Specifications

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

The Solid Waste Retrieval Facility--Phase 1 (Project W113) will provide the infrastructure and the facility required to retrieve from Trench 04, Burial ground 4C, contact handled (CH) drums and boxes at a rate that supports all retrieved TRU waste batching, treatment, storage, and disposal plans. This includes (1) operations related equipment and facilities, viz., a weather enclosure for the trench, retrieval equipment, weighing, venting, obtaining gas samples, overpacking, NDE, NDA, shipment of waste and (2) operations support related facilities, viz., a general office building, a retrieval staff change facility, and infrastructure upgrades such as supply and routing of water, sewer, electrical power, fire protection, roads, and telecommunication. Title I design for the operations related equipment and facilities was performed by Raytheon/BNFL, and that for the operations support related facilities including infrastructure upgrade was performed by KEH. These two scopes were combined into an integrated W113 Title II scope that was performed by Raytheon/BNFL. Volume 3 is a compilation of the construction specifications that will constitute the Title II materials and performance specifications. This volume contains CSI specifications for non-equipment related construction material type items, performance type items, and facility mechanical equipment items. Data sheets are provided, as necessary, which specify the equipment overall design parameters.

26 CFR 48.4216(a)-3 - Other items relating to tax on sale price.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Other items relating to tax on sale price. 48.4216(a)-3 Section 48.4216(a)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... reason of the failure of the article under a warranty as to its quality or service, and a new article is...

Adaptive memory: the survival scenario enhances item-specific processing relative to a moving scenario.

Science.gov (United States)

Burns, Daniel J; Hart, Joshua; Griffith, Samantha E; Burns, Amy D

2013-01-01

Nairne, Thompson, and Pandeirada (2007) found that retention of words rated for their relevance to survival is superior to that of words encoded under numerous other deep processing conditions. They suggested that our memory systems might have evolved to confer an advantage for survival-relevant information. Burns, Burns, and Hwang (2011) suggested a two-process explanation of the proximate mechanisms responsible for the survival advantage. Whereas most control tasks encourage only one type of processing, the survival task encourages both item-specific and relational processing. They found that when control tasks encouraged both types of processing, the survival processing advantage was eliminated. However, none of their control conditions included non-survival scenarios (e.g., moving, vacation, etc.), so it is not clear how this two-process explanation would explain the survival advantage when scenarios are used as control conditions. The present experiments replicated the finding that the survival scenario improves recall relative to a moving scenario in both a between-lists and within-list design and also provided evidence that this difference was accompanied by an item-specific processing difference, not a difference in relational processing. The implications of these results for several existing accounts of the survival processing effect are discussed.

Analysis of differential item functioning in the depression item bank from the Patient Reported Outcome Measurement Information System (PROMIS: An item response theory approach

Directory of Open Access Journals (Sweden)

JOSEPH P. EIMICKE

2009-06-01

Full Text Available The aims of this paper are to present findings related to differential item functioning (DIF in the Patient Reported Outcome Measurement Information System (PROMIS depression item bank, and to discuss potential threats to the validity of results from studies of DIF. The 32 depression items studied were modified from several widely used instruments. DIF analyses of gender, age and education were performed using a sample of 735 individuals recruited by a survey polling firm. DIF hypotheses were generated by asking content experts to indicate whether or not they expected DIF to be present, and the direction of the DIF with respect to the studied comparison groups. Primary analyses were conducted using the graded item response model (for polytomous, ordered response category data with likelihood ratio tests of DIF, accompanied by magnitude measures. Sensitivity analyses were performed using other item response models and approaches to DIF detection. Despite some caveats, the items that are recommended for exclusion or for separate calibration were "I felt like crying" and "I had trouble enjoying things that I used to enjoy." The item, "I felt I had no energy," was also flagged as evidencing DIF, and recommended for additional review. On the one hand, false DIF detection (Type 1 error was controlled to the extent possible by ensuring model fit and purification. On the other hand, power for DIF detection might have been compromised by several factors, including sparse data and small sample sizes. Nonetheless, practical and not just statistical significance should be considered. In this case the overall magnitude and impact of DIF was small for the groups studied, although impact was relatively large for some individuals.

Selection of detailed items for periodic safety review on PWR radwaste management system

Energy Technology Data Exchange (ETDEWEB)

Sung, K. B.; Ahn, Y. S.; Park, Y. S.; Kim, S. H.; Kim, J. T. [Korea Hydric and Nuclear Power Company, Taejon (Korea, Republic of)

2003-10-01

Selection of detailed-items for Periodic Safety Review on PWR radwaste management system, the main component could be faithfully clarified according to the purpose of establishment on each system and basic purpose. It is proper to select detailed-items those of radioactivities in the reactor coolant activity levels and the released volume of liquid and gaseous radioactive material on safety performance. It's also proper to select solid radwaste production quantities as detailed-item that it would be predict the next ten years trends after PSR.

The role of relational binding in item memory: evidence from face recognition in a case of developmental amnesia.

Science.gov (United States)

Olsen, Rosanna K; Lee, Yunjo; Kube, Jana; Rosenbaum, R Shayna; Grady, Cheryl L; Moscovitch, Morris; Ryan, Jennifer D

2015-04-01

Current theories state that the hippocampus is responsible for the formation of memory representations regarding relations, whereas extrahippocampal cortical regions support representations for single items. However, findings of impaired item memory in hippocampal amnesics suggest a more nuanced role for the hippocampus in item memory. The hippocampus may be necessary when the item elements need to be bound within and across episodes to form a lasting representation that can be used flexibly. The current investigation was designed to test this hypothesis in face recognition. H.C., an individual who developed with a compromised hippocampal system, and control participants incidentally studied individual faces that either varied in presentation viewpoint across study repetitions or remained in a fixed viewpoint across the study repetitions. Eye movements were recorded during encoding and participants then completed a surprise recognition memory test. H.C. demonstrated altered face viewing during encoding. Although the overall number of fixations made by H.C. was not significantly different from that of controls, the distribution of her viewing was primarily directed to the eye region. Critically, H.C. was significantly impaired in her ability to subsequently recognize faces studied from variable viewpoints, but demonstrated spared performance in recognizing faces she encoded from a fixed viewpoint, implicating a relationship between eye movement behavior in the service of a hippocampal binding function. These findings suggest that a compromised hippocampal system disrupts the ability to bind item features within and across study repetitions, ultimately disrupting recognition when it requires access to flexible relational representations. Copyright © 2015 the authors 0270-6474/15/355342-09$15.00/0.

Collaborative Filtering Based on Sequential Extraction of User-Item Clusters

Science.gov (United States)

Honda, Katsuhiro; Notsu, Akira; Ichihashi, Hidetomo

Collaborative filtering is a computational realization of “word-of-mouth” in network community, in which the items prefered by “neighbors” are recommended. This paper proposes a new item-selection model for extracting user-item clusters from rectangular relation matrices, in which mutual relations between users and items are denoted in an alternative process of “liking or not”. A technique for sequential co-cluster extraction from rectangular relational data is given by combining the structural balancing-based user-item clustering method with sequential fuzzy cluster extraction appraoch. Then, the tecunique is applied to the collaborative filtering problem, in which some items may be shared by several user clusters.

Using automatic item generation to create multiple-choice test items.

Science.gov (United States)

Gierl, Mark J; Lai, Hollis; Turner, Simon R

2012-08-01

Many tests of medical knowledge, from the undergraduate level to the level of certification and licensure, contain multiple-choice items. Although these are efficient in measuring examinees' knowledge and skills across diverse content areas, multiple-choice items are time-consuming and expensive to create. Changes in student assessment brought about by new forms of computer-based testing have created the demand for large numbers of multiple-choice items. Our current approaches to item development cannot meet this demand. We present a methodology for developing multiple-choice items based on automatic item generation (AIG) concepts and procedures. We describe a three-stage approach to AIG and we illustrate this approach by generating multiple-choice items for a medical licensure test in the content area of surgery. To generate multiple-choice items, our method requires a three-stage process. Firstly, a cognitive model is created by content specialists. Secondly, item models are developed using the content from the cognitive model. Thirdly, items are generated from the item models using computer software. Using this methodology, we generated 1248 multiple-choice items from one item model. Automatic item generation is a process that involves using models to generate items using computer technology. With our method, content specialists identify and structure the content for the test items, and computer technology systematically combines the content to generate new test items. By combining these outcomes, items can be generated automatically. © Blackwell Publishing Ltd 2012.

Human resource management in the delivery of postal items

Directory of Open Access Journals (Sweden)

Kujačić Momčilo D.

2015-01-01

Full Text Available Delivery of postal items is the last phase in the postal conveyance process. This phase involved up to 57% in total costs of postal items conveyance. In order to reduce the costs of delivery phase, postal organizations apply different methods and techniques. Legal and technological regulations, various restrictions regarding the selection and deployment of employees influence the choice of appropriate methods. Also, the principle of availability of the universal postal service is an essential factor in defining the optimal model. In this paper, the model for assessing and planning of the number of employees in the delivery service observed postal operator has been proposed, with respect to the principles of productivity and accessibility constraints of the universal postal service. This paper will analyze the impact of daily fluctuations in the number of full-time employees and the possibility of hiring a part-time workers in the days with increased traffic volume in the delivery of items, when usually the items from large customers are delivered.

Volume of hippocampal subfields and episodic memory in childhood and adolescence.

Science.gov (United States)

Lee, Joshua K; Ekstrom, Arne D; Ghetti, Simona

2014-07-01

Episodic memory critically depends on the hippocampus to bind the features of an experience into memory. Episodic memory develops in childhood and adolescence, and hippocampal changes during this period may contribute to this development. Little is known, however, about how the hippocampus contributes to episodic memory development. The hippocampus is comprised of several cytoarchitectural subfields with functional significance for episodic memory. However, hippocampal subfields have not been assessed in vivo during child development, nor has their relation with episodic memory been assessed during this period. In the present study, high-resolution T2-weighted images of the hippocampus were acquired in 39 children and adolescents aged 8 to 14 years (M=11.30, SD=2.38), and hippocampal subfields were segmented using a protocol previously validated in adult populations. We first validated the method in children and adolescents and examined age-related differences in hippocampal subfields and correlations between subfield volumes and episodic memory. Significant age-related increases in the subfield volume were observed into early adolescence in the right CA3/DG and CA1. The right CA3/DG subfield volumes were positively correlated with accurate episodic memory for item-color relations, and the right CA3/DG and subiculum were negatively correlated with item false alarm rates. Subfield development appears to follow a protracted developmental trajectory, and likely plays a pivotal role in episodic memory development. Copyright © 2014 Elsevier Inc. All rights reserved.

The order and volume fill rates in inventory control systems

DEFF Research Database (Denmark)

Thorstenson, Anders; Larsen, Christian

2011-01-01

This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level...... measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...

A review of the effects on IRT item parameter estimates with a focus on misbehaving common items in test equating

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Michalis P Michaelides

2010-10-01

Full Text Available Many studies have investigated the topic of change or drift in item parameter estimates in the context of Item Response Theory. Content effects, such as instructional variation and curricular emphasis, as well as context effects, such as the wording, position, or exposure of an item have been found to impact item parameter estimates. The issue becomes more critical when items with estimates exhibiting differential behavior across test administrations are used as common for deriving equating transformations. This paper reviews the types of effects on IRT item parameter estimates and focuses on the impact of misbehaving or aberrant common items on equating transformations. Implications relating to test validity and the judgmental nature of the decision to keep or discard aberrant common items are discussed, with recommendations for future research into more informed and formal ways of dealing with misbehaving common items.

A Review of the Effects on IRT Item Parameter Estimates with a Focus on Misbehaving Common Items in Test Equating.

Science.gov (United States)

Michaelides, Michalis P

2010-01-01

Many studies have investigated the topic of change or drift in item parameter estimates in the context of item response theory (IRT). Content effects, such as instructional variation and curricular emphasis, as well as context effects, such as the wording, position, or exposure of an item have been found to impact item parameter estimates. The issue becomes more critical when items with estimates exhibiting differential behavior across test administrations are used as common for deriving equating transformations. This paper reviews the types of effects on IRT item parameter estimates and focuses on the impact of misbehaving or aberrant common items on equating transformations. Implications relating to test validity and the judgmental nature of the decision to keep or discard aberrant common items are discussed, with recommendations for future research into more informed and formal ways of dealing with misbehaving common items.

Psychometric properties of the Centers for Disease Control and Prevention Health-Related Quality of Life (CDC HRQOL items in adults with arthritis

Directory of Open Access Journals (Sweden)

DeVellis Robert

2006-09-01

Full Text Available Abstract Background Measuring health-related quality of life (HRQOL is important in arthritis and the SF-36v2 is the current state-of-the-art. It is only emerging how well the Centers for Disease Control and Prevention (CDC HRQOL measures HRQOL for people with arthritis. This study's purpose is to assess the psychometric properties of the 9-item CDC HRQOL (4-item Healthy Days Core Module and 5-item Healthy Days Symptoms Module in an arthritis sample using the SF-36v2 as a comparison. Methods In Fall 2002, a cross-sectional study acquired survey data including the CDC HRQOL and SF-36v2 from 2 North Carolina populations of adult patients reporting osteoarthritis, rheumatoid arthritis, and fibromyalgia; 2182 (52% responded. The first item of both the CDC HRQOL and the SF-36v2 was general health (GEN. All 8 other CDC HRQOL items ask for the number of days in the past 30 days that respondents experienced various aspects of HRQOL. Exploratory principal components analyses (PCA were conducted on each sample and the combined samples of the CDC HRQOL. The multitrait-multimethod matrix (MTMM was used to compute correlations between each trait (physical health and mental health and between each method of measurement (CDC HRQOL and SF36v2. The relative contribution of the CDC HRQOL in predicting the physical component summary (PCS and the mental component summary (MCS was determined by regressing the CDC HRQOL items on the PCS and MCS scales. Results All 9 CDC HRQOL items loaded primarily onto 1 factor (explaining 57% of the item variance representing a reasonable solution for capturing overall HRQOL. After rotation a 2 factor interpretation for the 9 items was clear, with 4 items capturing physical health (physical, activity, pain, and energy days and 3 items capturing mental health (mental, depression, and anxiety days. All of the loadings for these two factors were greater than 0.70. The CDC HRQOL physical health factor correlated with PCS (r = -.78, p 2

The 1992 Pacific Northwest Residential Energy Survey : Phase 1 : Book 4 : Item-by-item Crosstabulations.

Energy Technology Data Exchange (ETDEWEB)

United States. Bonneville Power Administration. End-Use Research Section; Applied Management & Planning Group (Firm)

1993-06-01

This book constitutes a portion of the primary documentation for the 1992 Pacific Northwest Residential Energy Survey, Phase I. The complete 33-volume set of primary documentation provides information needed by energy analysts and interpreters with respect to planning, execution, data collection, and data management of the PNWRES92-I process. Thirty of these volumes are devoted to different ``views`` of the data themselves, with each view having a special purpose or interest as its focus. Analyses and interpretations of these data will be the subjects of forthcoming publications. Conducted during the late summer and fall months of 1992, PNWRES92-I had the over-arching goal of satisfying basic requirements for a variety of information about the stock of residential units in Bonneville`s service region. Surveys with a similar goal were conducted in 1979 and 1983. This volume discerns the information by state. ``Selected crosstabulations`` refers to a set of nine survey items of wide interest (Dwelling Type, Ownership Type, Year-of-Construction, Dwelling Size, Primary Space-Heating Fuel, Primary Water-Heating Fuel, Household Income for 1991, Utility Type, and Space-Heating Fuels: Systems and Equipment) that were crosstabulated among themselves.

Assessing item fit for unidimensional item response theory models using residuals from estimated item response functions.

Science.gov (United States)

Haberman, Shelby J; Sinharay, Sandip; Chon, Kyong Hee

2013-07-01

Residual analysis (e.g. Hambleton & Swaminathan, Item response theory: principles and applications, Kluwer Academic, Boston, 1985; Hambleton, Swaminathan, & Rogers, Fundamentals of item response theory, Sage, Newbury Park, 1991) is a popular method to assess fit of item response theory (IRT) models. We suggest a form of residual analysis that may be applied to assess item fit for unidimensional IRT models. The residual analysis consists of a comparison of the maximum-likelihood estimate of the item characteristic curve with an alternative ratio estimate of the item characteristic curve. The large sample distribution of the residual is proved to be standardized normal when the IRT model fits the data. We compare the performance of our suggested residual to the standardized residual of Hambleton et al. (Fundamentals of item response theory, Sage, Newbury Park, 1991) in a detailed simulation study. We then calculate our suggested residuals using data from an operational test. The residuals appear to be useful in assessing the item fit for unidimensional IRT models.

Federal Logistics Information System (FLIS) Procedures Manual, Volume 4. Item Identification.

Science.gov (United States)

1995-01-01

Functional I DRMS Defense Reutilization 1,15 Description and Marketing FDM Full Descriptive 2 Service Method (Item DPSC Defense Personnel 2,13,14...under DIC KRE, return code ment or segment mix of FLIS data. For interna- AU. tional cataloging, only one Output Data RequestV Code may be used per...Screening Results) with KMR (Matching NATO Maintenance and Supply Agency (NAMSA), Reference-Screening) and either KFC (File Data the custodian for control

Teasing apart the contributions of hard dietary items on 3D dental microtextures in primates.

Science.gov (United States)

Calandra, Ivan; Schulz, Ellen; Pinnow, Mona; Krohn, Susanne; Kaiser, Thomas M

2012-07-01

3D dental microtexture analysis is a powerful tool for reconstructing the diets of extinct primates. This method is based on the comparison of fossils with extant species of known diet. The diets of primates are highly diversified and include fruits, seeds, grass, tree leaves, bark, roots, tubers, and animal resources. Fruits remain the main component in the diets of most primates. We tested whether the proportion of fruit consumed is correlated with dental microtexture. Two methods of microtexture analysis, the scale-sensitive fractal analysis (SSFA) and the Dental Areal Surface Texture Analysis (DASTA; after ISO/FDIS 25178-2), were applied to specimens of eight primate species (Alouatta seniculus, Gorilla gorilla, Lophocebus albigena, Macaca fascicularis, Pan troglodytes, Papio cynocephalus, Pongo abelii, Theropithecus gelada). These species largely differ in the mean annual proportion of fruit (from 0 to 90%) in their diet, as well as in their consumption of other hard items (seeds, bark, and insect cuticles) and of abrasive plants. We find the complexity and heterogeneity of textures (SSFA) to correlate with the proportion of fruits consumed. Textural fill volume (SSFA) indicates the proportion of both fruits and other hard items processed. Furthermore, anisotropy (SSFA) relates to the consumption of abrasive plants like grass and other monocots. ISO parameters valley height, root mean square height, material volume, density of peaks, and closed hill and dale areas (DASTA) describe the functional interaction between food items and enamel facets during mastication. The shallow, plastic deformation of enamel surfaces induced by small hard particles, such as phytoliths or dust, results in flat microtexture relief, whereas the brittle, deep fracture caused by large hard items such as hard seeds creates larger relief. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

78 FR 29392 - Embedded Digital Devices in Safety-Related Systems, Systems Important to Safety, and Items Relied...

Science.gov (United States)

2013-05-20

... NUCLEAR REGULATORY COMMISSION [NRC-2013-0098] Embedded Digital Devices in Safety-Related Systems, Systems Important to Safety, and Items Relied on for Safety AGENCY: Nuclear Regulatory Commission. ACTION... (NRC) is issuing for public comment Draft Regulatory Issue Summary (RIS) 2013-XX, ``Embedded Digital...

Calibration of Automatically Generated Items Using Bayesian Hierarchical Modeling.

Science.gov (United States)

Johnson, Matthew S.; Sinharay, Sandip

For complex educational assessments, there is an increasing use of "item families," which are groups of related items. However, calibration or scoring for such an assessment requires fitting models that take into account the dependence structure inherent among the items that belong to the same item family. C. Glas and W. van der Linden…

The 12-item World Health Organization Disability Assessment Schedule II (WHO-DAS II: a nonparametric item response analysis

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Fernandez Ana

2010-05-01

Full Text Available Abstract Background Previous studies have analyzed the psychometric properties of the World Health Organization Disability Assessment Schedule II (WHO-DAS II using classical omnibus measures of scale quality. These analyses are sample dependent and do not model item responses as a function of the underlying trait level. The main objective of this study was to examine the effectiveness of the WHO-DAS II items and their options in discriminating between changes in the underlying disability level by means of item response analyses. We also explored differential item functioning (DIF in men and women. Methods The participants were 3615 adult general practice patients from 17 regions of Spain, with a first diagnosed major depressive episode. The 12-item WHO-DAS II was administered by the general practitioners during the consultation. We used a non-parametric item response method (Kernel-Smoothing implemented with the TestGraf software to examine the effectiveness of each item (item characteristic curves and their options (option characteristic curves in discriminating between changes in the underliying disability level. We examined composite DIF to know whether women had a higher probability than men of endorsing each item. Results Item response analyses indicated that the twelve items forming the WHO-DAS II perform very well. All items were determined to provide good discrimination across varying standardized levels of the trait. The items also had option characteristic curves that showed good discrimination, given that each increasing option became more likely than the previous as a function of increasing trait level. No gender-related DIF was found on any of the items. Conclusions All WHO-DAS II items were very good at assessing overall disability. Our results supported the appropriateness of the weights assigned to response option categories and showed an absence of gender differences in item functioning.

Item level diagnostics and model - data fit in item response theory ...

African Journals Online (AJOL)

Item response theory (IRT) is a framework for modeling and analyzing item response data. Item-level modeling gives IRT advantages over classical test theory. The fit of an item score pattern to an item response theory (IRT) models is a necessary condition that must be assessed for further use of item and models that best fit ...

Dose-volume correlation in radiation-related late small-bowel complication

International Nuclear Information System (INIS)

Letschert, J.G.J.; Lebesque, J.V.; Boer, R.W. de; hart, A.A.M.; Barteling, H.

1990-01-01

The effects of the volume of irradiated small bowel on late small-bowel tolerance was studied, taking into account the equivalent total dose ant type of pre-irradiation surgical procedure. A method was developed to estimate small-bowel volumes in the high-bowel volumes were measured for three-field and AP-PA pelvic treatments (165 cm 3 and 400 cm 3 , respectively), extended AP-PA treatment of para-aortic and iliac nodes (1000 cm 3 ). In a retrospective study of 111 patientst irradiated after surgery for rectal or recto-sigmoid cancer to a dose of 45-50 Gy in 5 weeks, extended AP-PA pelvic treatment (n = 27) resulted in a high incidence of severe small-bowel complications (37%), whereas for limited (three-field) pelvic treatment (n = 84) the complication rate was 6%. These complication data together with data from the literature on postoperative radiation-related small-bowel complications were analysed using the maximum likelihood method to fit the data to the logistic form of the dose-response relation, taking the volume effect into account by a power law. The analysis indicated that the incidence of radiation-related small-bowel compllications was higher after rectal surgery than after other types of surgery, which might be explained by the development of more adhesions. For both types of surgery a volume exponent of the power-law of 0.26 ± 0.05 was established. This means that if the small-bowel volume is increased by a factor of 2, the total dose has to be reduced by 17% for the same incidence of small-bowel complications. (author). 45 refs.; 6 figs.; 4 tabs

Validation of a 10-item care-related regret intensity scale (RIS-10) for health care professionals.

Science.gov (United States)

Courvoisier, Delphine S; Cullati, Stéphane; Haller, Chiara S; Schmidt, Ralph E; Haller, Guy; Agoritsas, Thomas; Perneger, Thomas V

2013-03-01

Regret after one of the many decisions and interventions that health care professionals make every day can have an impact on their own health and quality of life, and on their patient care practices. To validate a new care-related regret intensity scale (RIS) for health care professionals. Retrospective cross-sectional cohort study with a 1-month follow-up (test-retest) in a French-speaking University Hospital. A total of 469 nurses and physicians responded to the survey, and 175 answered the retest. RIS, self-report questions on the context of the regret-inducing event, its consequences for the patient, involvement of the health care professionals, and changes in patient care practices after the event. We measured the impact of regret intensity on health care professionals with the satisfaction with life scale, the SF-36 first question (self-reported health), and a question on self-esteem. On the basis of factor analysis and item response analysis, the initial 19-item scale was shortened to 10 items. The resulting scale (RIS-10) was unidimensional and had high internal consistency (α=0.87) and acceptable test-retest reliability (0.70). Higher regret intensity was associated with (a) more consequences for the patient; (b) lower life satisfaction and poorer self-reported health in health care professionals; and (c) changes in patient care practices. Nurses reported analyzing the event and apologizing, whereas physicians reported talking preferentially to colleagues, rather than to their supervisor, about changing practices. The RIS is a valid and reliable measure of care-related regret intensity for hospital-based physicians and nurses.

Method of data mining including determining multidimensional coordinates of each item using a predetermined scalar similarity value for each item pair

Science.gov (United States)

Meyers, Charles E.; Davidson, George S.; Johnson, David K.; Hendrickson, Bruce A.; Wylie, Brian N.

1999-01-01

A method of data mining represents related items in a multidimensional space. Distance between items in the multidimensional space corresponds to the extent of relationship between the items. The user can select portions of the space to perceive. The user also can interact with and control the communication of the space, focusing attention on aspects of the space of most interest. The multidimensional spatial representation allows more ready comprehension of the structure of the relationships among the items.

A novel multi-item joint replenishment problem considering multiple type discounts.

Directory of Open Access Journals (Sweden)

Ligang Cui

Full Text Available In business replenishment, discount offers of multi-item may either provide different discount schedules with a single discount type, or provide schedules with multiple discount types. The paper investigates the joint effects of multiple discount schemes on the decisions of multi-item joint replenishment. In this paper, a joint replenishment problem (JRP model, considering three discount (all-unit discount, incremental discount, total volume discount offers simultaneously, is constructed to determine the basic cycle time and joint replenishment frequencies of multi-item. To solve the proposed problem, a heuristic algorithm is proposed to find the optimal solutions and the corresponding total cost of the JRP model. Numerical experiment is performed to test the algorithm and the computational results of JRPs under different discount combinations show different significance in the replenishment cost reduction.

Brain volumes in relatives of patients with schizophrenia - A meta-analysis

NARCIS (Netherlands)

Boos, Heleen B. M.; Aleman, Andre; Cahn, Wiepke; Pol, Hilleke Hulshoff; Kahn, Rene S.

Context: Smaller brain volumes have consistently been found in patients with schizophrenia, particularly in gray matter and medial temporal lobe structures. Although several studies have investigated brain volumes in nonpsychotic relatives of patients with schizophrenia, results have been

Item response theory - A first approach

Science.gov (United States)

Nunes, Sandra; Oliveira, Teresa; Oliveira, Amílcar

2017-07-01

The Item Response Theory (IRT) has become one of the most popular scoring frameworks for measurement data, frequently used in computerized adaptive testing, cognitively diagnostic assessment and test equating. According to Andrade et al. (2000), IRT can be defined as a set of mathematical models (Item Response Models - IRM) constructed to represent the probability of an individual giving the right answer to an item of a particular test. The number of Item Responsible Models available to measurement analysis has increased considerably in the last fifteen years due to increasing computer power and due to a demand for accuracy and more meaningful inferences grounded in complex data. The developments in modeling with Item Response Theory were related with developments in estimation theory, most remarkably Bayesian estimation with Markov chain Monte Carlo algorithms (Patz & Junker, 1999). The popularity of Item Response Theory has also implied numerous overviews in books and journals, and many connections between IRT and other statistical estimation procedures, such as factor analysis and structural equation modeling, have been made repeatedly (Van der Lindem & Hambleton, 1997). As stated before the Item Response Theory covers a variety of measurement models, ranging from basic one-dimensional models for dichotomously and polytomously scored items and their multidimensional analogues to models that incorporate information about cognitive sub-processes which influence the overall item response process. The aim of this work is to introduce the main concepts associated with one-dimensional models of Item Response Theory, to specify the logistic models with one, two and three parameters, to discuss some properties of these models and to present the main estimation procedures.

Item-cued directed forgetting of related words and pictures in children and adults: selective rehearsal versus cognitive inhibition.

Science.gov (United States)

Lehman, E B; McKinley-Pace, M; Leonard, A M; Thompson, D; Johns, K

2001-01-01

The main purpose of this study was to compare the relative importance of selective rehearsal and cognitive inhibition in accounting for developmental changes in the directed-forgetting paradigm developed by R. A. Bjork (1972). In two experiments, children in Grades 2 and 5 and college students were asked to remember some words or pictures and to forget others when items were categorically related. Their memory for both items and the associated remember or forget cues was then tested with recall and recognition. Fifth graders recognized more of the forget-cued words than college students did. The pattern of results suggested that age differences in rehearsal and source monitoring (i.e., remembering whether a word had been cued remember or forget) were better explanatory mechanisms for children's forgetting inefficiencies than retrieval inhibition was. The results are discussed in terms of a multiple process view of inhibition.

Enactment versus observation: item-specific and relational processing in goal-directed action sequences (and lists of single actions.

Directory of Open Access Journals (Sweden)

Janette Schult

Full Text Available What are the memory-related consequences of learning actions (such as "apply the patch" by enactment during study, as compared to action observation? Theories converge in postulating that enactment encoding increases item-specific processing, but not the processing of relational information. Typically, in the laboratory enactment encoding is studied for lists of unrelated single actions in which one action execution has no overarching purpose or relation with other actions. In contrast, real-life actions are usually carried out with the intention to achieve such a purpose. When actions are embedded in action sequences, relational information provides efficient retrieval cues. We contrasted memory for single actions with memory for action sequences in three experiments. We found more reliance on relational processing for action-sequences than single actions. To what degree can this relational information be used after enactment versus after the observation of an actor? We found indicators of superior relational processing after observation than enactment in ordered pair recall (Experiment 1A and in emerging subjective organization of repeated recall protocols (recall runs 2-3, Experiment 2. An indicator of superior item-specific processing after enactment compared to observation was recognition (Experiment 1B, Experiment 2. Similar net recall suggests that observation can be as good a learning strategy as enactment. We discuss possible reasons why these findings only partly converge with previous research and theorizing.

Variation in orbitofrontal cortex volume: relation to sex, emotion regulation and affect.

Science.gov (United States)

Welborn, B Locke; Papademetris, Xenophon; Reis, Deidre L; Rajeevan, Nallakkandi; Bloise, Suzanne M; Gray, Jeremy R

2009-12-01

Sex differences in brain structure have been examined extensively but are not completely understood, especially in relation to possible functional correlates. Our two aims in this study were to investigate sex differences in brain structure, and to investigate a possible relation between orbitofrontal cortex subregions and affective individual differences. We used tensor-based morphometry to estimate local brain volume from MPRAGE images in 117 healthy right-handed adults (58 female), age 18-40 years. We entered estimates of local brain volume as the dependent variable in a GLM, controlling for age, intelligence and whole-brain volume. Men had larger left planum temporale. Women had larger ventromedial prefrontal cortex (vmPFC), right lateral orbitofrontal (rlOFC), cerebellum, and bilateral basal ganglia and nearby white matter. vmPFC but not rlOFC volume covaried with self-reported emotion regulation strategies (reappraisal, suppression), expressivity of positive emotions (but not of negative), strength of emotional impulses, and cognitive but not somatic anxiety. vmPFC volume statistically mediated sex differences in emotion suppression. The results confirm prior reports of sex differences in orbitofrontal cortex structure, and are the first to show that normal variation in vmPFC volume is systematically related to emotion regulation and affective individual differences.

A Bifactor Multidimensional Item Response Theory Model for Differential Item Functioning Analysis on Testlet-Based Items

Science.gov (United States)

Fukuhara, Hirotaka; Kamata, Akihito

2011-01-01

A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…

Gender-Based Differential Item Performance in Mathematics Achievement Items.

Science.gov (United States)

Doolittle, Allen E.; Cleary, T. Anne

1987-01-01

Eight randomly equivalent samples of high school seniors were each given a unique form of the ACT Assessment Mathematics Usage Test (ACTM). Signed measures of differential item performance (DIP) were obtained for each item in the eight ACTM forms. DIP estimates were analyzed and a significant item category effect was found. (Author/LMO)

Drusen Volume and Retinal Pigment Epithelium Abnormal Thinning Volume Predict 2-Year Progression of Age-Related Macular Degeneration.

Science.gov (United States)

Folgar, Francisco A; Yuan, Eric L; Sevilla, Monica B; Chiu, Stephanie J; Farsiu, Sina; Chew, Emily Y; Toth, Cynthia A

2016-01-01

To analyze the value of novel measures of retinal pigment epithelium-drusen complex (RPEDC) volume to predict 2-year disease progression of intermediate age-related macular degeneration (AMD). Prospective, observational study. Three hundred forty-five AMD and 122 non-AMD participants enrolled in the Age Related Eye Disease Study 2 Ancillary Spectral-Domain (SD) Optical Coherence Tomography (OCT) study. High-density SD OCT macular volumes were obtained at yearly study visits. The RPEDC abnormal thickening (henceforth, OCT drusen) and RPEDC abnormal thinning (RAT) volumes were generated by semiautomated segmentation of total RPEDC within a 5-mm-diameter macular field. Volume change and odds ratio (OR) with 95% confidence intervals (CI) for progression to advanced AMD with choroidal neovascularization (CNV) or central geographic atrophy (GA). Complete volumes were obtained in 265 and 266 AMD eyes and in 115 and 97 control eyes at baseline and at year 2, respectively. In AMD eyes, mean (standard deviation) OCT drusen volume increased from 0.08 mm(3) (0.16 mm(3)) to 0.10 mm(3) (0.23 mm(3); P < 0.001), and RAT volume increased from 8.3 × 10(-4) mm(3) (20.8 × 10(-4) mm(3)) to 18.4 × 10(-4) mm(3) (46.6 × 10(-4) mm(3); P < 0.001). Greater baseline OCT drusen volume was associated with 2-year progression to CNV (P = 0.002). Odds of developing CNV increased by 31% for every 0.1-mm(3) increase in baseline OCT drusen volume (OR, 1.31; 95% CI, 1.06-1.63; P = 0.013). Greater baseline RAT volume was associated with significant 2-year increase in RAT volume (P < 0.001), noncentral GA (P < 0.001), and progression to central GA (P < 0.001). Odds of developing central GA increased by 32% for every 0.001-mm(3) increase in baseline RAT volume (OR, 1.32; 95% CI, 1.14-1.53; P < 0.001). In non-AMD eyes, all volumes were significantly lower than AMD eyes and showed no significant 2-year change. Macular OCT drusen and RAT volumes increased significantly in AMD eyes over 2 years

Does remembering emotional items impair recall of same-emotion items?

Science.gov (United States)

Sison, Jo Ann G; Mather, Mara

2007-04-01

In the part-set cuing effect, cuing a subset of previously studied items impairs recall of the remaining noncued items. This experiment reveals that cuing participants with previously-studied emotional pictures (e.g., fear-evoking pictures of people) can impair recall of pictures involving the same emotion but different content (e.g., fear-evoking pictures of animals). This indicates that new events can be organized in memory using emotion as a grouping function to create associations. However, whether new information is organized in memory along emotional or nonemotional lines appears to be a flexible process that depends on people's current focus. Mentioning in the instructions that the pictures were either amusement- or fear-related led to memory impairment for pictures with the same emotion as cued pictures, whereas mentioning that the pictures depicted either animals or people led to memory impairment for pictures with the same type of actor.

PENDETEKSIAN KEBERFUNGSIAN BUTIR PEMBEDA DENGAN INDEKS VOLUME SEDERHANA BERDASARKAN TEORI RESPONS BUTIR MULTIDIMENSI

Directory of Open Access Journals (Sweden)

Heri Retnawati

2013-12-01

Abstract The aim of the studi is to identify differential item fungtioning (DIF based on item response theory using bidimensional model. This study uses explorative quantitative approach. Data used in this study is a mathematics test of national exam 2003 data which has been proved to contain 2-dimensions (Badrun Kartowagiran & Heri Retnawati, 2007. The simple volume indices are used to detect DIF which is the development of the simple area indices. The testee are grouped based on their gender, groups of male students and female students. The item parameter estimation was performed with BILOG and TESTFACT, and then to estimate volume and draw the surface characteristics curve was conduct with MAPLE. The results showed that of the 28 items analyzed, 2 items potentially contained uniform DIF and 26 items potentially contained a non-uniform DIF.Keywords: unidimensional IRT, multidimensional IRT, DIF, UPD, SPD

Loglinear multidimensional IRT models for polytomously scored items

NARCIS (Netherlands)

Kelderman, Henk; Rijkes, Carl P.M.; Rijkes, Carl

1994-01-01

A loglinear IRT model is proposed that relates polytomously scored item responses to a multidimensional latent space. The analyst may specify a response function for each response, indicating which latent abilities are necessary to arrive at that response. Each item may have a different number of

45 CFR 61.9 - Reporting civil judgments related to the delivery of a health care item or service.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Reporting civil judgments related to the delivery of a health care item or service. 61.9 Section 61.9 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION HEALTHCARE INTEGRITY AND PROTECTION DATA BANK FOR FINAL ADVERSE INFORMATION...

Structural validity of a 16-item abridged version of the Cervantes Health-Related Quality of Life scale for menopause: the Cervantes Short-Form Scale.

Science.gov (United States)

Coronado, Pluvio J; Borrego, Rafael Sánchez; Palacios, Santiago; Ruiz, Miguel A; Rejas, Javier

2015-03-01

The Cervantes Scale is a specific health-related quality of life questionnaire that was originally developed in Spanish to be used in Spain for women through and beyond menopause. It contains 31 items and is time-consuming. The aim of this study was to produce an abridged version with the same dimensional structure and with similar psychometric properties. A representative sample of 516 postmenopausal women (mean [SD] age, 57 [4.31] y) seen in outpatient gynecology clinics and extracted from an observational cross-sectional study was used. Item analysis, internal consistency reliability, item-total and item-dimension correlations, and item correlation with the 12-item Medical Outcomes Study Short Form Health Survey Version 2.0 were studied. Dimensional and full-model confirmatory factor analyses were used to check structure stability. A threefold cross-validation method was used to obtain stable estimates by means of multigroup analysis. The scale was reduced to a 16-item version, the Cervantes Short-Form Scale, containing four main dimensions (Menopause and Health, Psychological, Sexuality, and Couple Relations), with the first dimension composed of three subdimensions (Vasomotor Symptoms, Health, and Aging). Goodness-of-fit statistics were better than those of the extended version (χ(2)/df = 2.493; adjusted goodness-of-fit index, 0.802; parsimony comparative fit index, 0.749; root mean standard error of approximation, 0.054). Internal consistency was good (Cronbach's α = 0.880). Correlations between the extended and the reduced dimensions were high and significant in all cases (P < 0.001; r values ranged from 0.90 for Sexuality to 0.969 for Vasomotor Symptoms). The Cervantes Scale can be reduced to a 16-item abridged version (Cervantes Short-Form Scale) that maintains the original dimensional structure and psychometric properties. At 51% of the original length, this version can be administered faster, making it especially suitable for routine medical practice.

ACER Chemistry Test Item Collection (ACER CHEMTIC Year 12 Supplement).

Science.gov (United States)

Australian Council for Educational Research, Hawthorn.

This publication contains 317 multiple-choice chemistry test items related to topics covered in the Victorian (Australia) Year 12 chemistry course. It allows teachers access to a range of items suitable for diagnostic and achievement purposes, supplementing the ACER Chemistry Test Item Collection--Year 12 (CHEMTIC). The topics covered are: organic…

[Instrument to measure adherence in hypertensive patients: contribution of Item Response Theory].

Science.gov (United States)

Rodrigues, Malvina Thaís Pacheco; Moreira, Thereza Maria Magalhaes; Vasconcelos, Alexandre Meira de; Andrade, Dalton Francisco de; Silva, Daniele Braz da; Barbetta, Pedro Alberto

2013-06-01

To analyze, by means of "Item Response Theory", an instrument to measure adherence to t treatment for hypertension. Analytical study with 406 hypertensive patients with associated complications seen in primary care in Fortaleza, CE, Northeastern Brazil, 2011 using "Item Response Theory". The stages were: dimensionality test, calibrating the items, processing data and creating a scale, analyzed using the gradual response model. A study of the dimensionality of the instrument was conducted by analyzing the polychoric correlation matrix and factor analysis of complete information. Multilog software was used to calibrate items and estimate the scores. Items relating to drug therapy are the most directly related to adherence while those relating to drug-free therapy need to be reworked because they have less psychometric information and low discrimination. The independence of items, the small number of levels in the scale and low explained variance in the adjustment of the models show the main weaknesses of the instrument analyzed. The "Item Response Theory" proved to be a relevant analysis technique because it evaluated respondents for adherence to treatment for hypertension, the level of difficulty of the items and their ability to discriminate between individuals with different levels of adherence, which generates a greater amount of information. The instrument analyzed is limited in measuring adherence to hypertension treatment, by analyzing the "Item Response Theory" of the item, and needs adjustment. The proper formulation of the items is important in order to accurately measure the desired latent trait.

Development of Test Items Related to Selected Concepts Within the Scheme the Particle Nature of Matter.

Science.gov (United States)

Doran, Rodney L.; Pella, Milton O.

The purpose of this study was to develop tests items with a minimum reading demand for use with pupils at grade levels two through six. An item was judged to be acceptable if the item satisfied at least four of six criteria. Approximately 250 students in grades 2-6 participated in the study. Half of the students were given instruction to develop…

The order and volume fill rates in inventory control systems

DEFF Research Database (Denmark)

Thorstenson, Anders; Larsen, Christian

2014-01-01

This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total demanded quantity the order fill rate would be the preferred service...... level measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...... extensions consider more general inventory control review policies with backordering, as well as some relations between service measures. A particularly important result in the paper concerns an alternative service measure, the customer order fill rate, and shows how this measure always exceeds the other two...

Constructing the 32-item Fitness-to-Drive Screening Measure.

Science.gov (United States)

Medhizadah, Shabnam; Classen, Sherrilene; Johnson, Andrew M

2018-04-01

The Fitness-to-Drive Screening Measure © (FTDS) enables proxies to identify at-risk older drivers via 54 driving-related items, but may be too lengthy for widespread uptake. We reduced the number of items in the FTDS and validated the shorter measure, using 200 caregiver responses. Exploratory factor analysis and classical test theory techniques were used to determine the most interpretable factor model and the minimum number of items to be used for predicting fitness to drive. The extent to which the shorter FTDS predicted the results of the 54-item FTDS was evaluated through correlational analysis. A three-factor model best represented the empirical data. Classical test theory techniques lead to the development of the 32-item FTDS. The 32-item FTDS was highly correlated ( r = .99, p = .05) with the FTDS. The 32-item FTDS may provide raters with a faster and more efficient way to identify at-risk older drivers.

Evaluation of item candidates for a diabetic retinopathy quality of life item bank.

Science.gov (United States)

Fenwick, Eva K; Pesudovs, Konrad; Khadka, Jyoti; Rees, Gwyn; Wong, Tien Y; Lamoureux, Ecosse L

2013-09-01

We are developing an item bank assessing the impact of diabetic retinopathy (DR) on quality of life (QoL) using a rigorous multi-staged process combining qualitative and quantitative methods. We describe here the first two qualitative phases: content development and item evaluation. After a comprehensive literature review, items were generated from four sources: (1) 34 previously validated patient-reported outcome measures; (2) five published qualitative articles; (3) eight focus groups and 18 semi-structured interviews with 57 DR patients; and (4) seven semi-structured interviews with diabetes or ophthalmic experts. Items were then evaluated during 3 stages, namely binning (grouping) and winnowing (reduction) based on key criteria and panel consensus; development of item stems and response options; and pre-testing of items via cognitive interviews with patients. The content development phase yielded 1,165 unique items across 7 QoL domains. After 3 sessions of binning and winnowing, items were reduced to a minimally representative set (n = 312) across 9 domains of QoL: visual symptoms; ocular surface symptoms; activity limitation; mobility; emotional; health concerns; social; convenience; and economic. After 8 cognitive interviews, 42 items were amended resulting in a final set of 314 items. We have employed a systematic approach to develop items for a DR-specific QoL item bank. The psychometric properties of the nine QoL subscales will be assessed using Rasch analysis. The resulting validated item bank will allow clinicians and researchers to better understand the QoL impact of DR and DR therapies from the patient's perspective.

Three controversies over item disclosure in medical licensure examinations

Directory of Open Access Journals (Sweden)

Yoon Soo Park

2015-09-01

Full Text Available In response to views on public's right to know, there is growing attention to item disclosure – release of items, answer keys, and performance data to the public – in medical licensure examinations and their potential impact on the test's ability to measure competence and select qualified candidates. Recent debates on this issue have sparked legislative action internationally, including South Korea, with prior discussions among North American countries dating over three decades. The purpose of this study is to identify and analyze three issues associated with item disclosure in medical licensure examinations – 1 fairness and validity, 2 impact on passing levels, and 3 utility of item disclosure – by synthesizing existing literature in relation to standards in testing. Historically, the controversy over item disclosure has centered on fairness and validity. Proponents of item disclosure stress test takers’ right to know, while opponents argue from a validity perspective. Item disclosure may bias item characteristics, such as difficulty and discrimination, and has consequences on setting passing levels. To date, there has been limited research on the utility of item disclosure for large scale testing. These issues requires ongoing and careful consideration.

Guide to good practices for the development of test items

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-01

While the methodology used in developing test items can vary significantly, to ensure quality examinations, test items should be developed systematically. Test design and development is discussed in the DOE Guide to Good Practices for Design, Development, and Implementation of Examinations. This guide is intended to be a supplement by providing more detailed guidance on the development of specific test items. This guide addresses the development of written examination test items primarily. However, many of the concepts also apply to oral examinations, both in the classroom and on the job. This guide is intended to be used as guidance for the classroom and laboratory instructor or curriculum developer responsible for the construction of individual test items. This document focuses on written test items, but includes information relative to open-reference (open book) examination test items, as well. These test items have been categorized as short-answer, multiple-choice, or essay. Each test item format is described, examples are provided, and a procedure for development is included. The appendices provide examples for writing test items, a test item development form, and examples of various test item formats.

Negative affect impairs associative memory but not item memory.

Science.gov (United States)

Bisby, James A; Burgess, Neil

2013-12-17

The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine the effects of emotion on memory for items and their associations. By presenting neutral and negative items with background contexts, Experiment 1 demonstrated that item memory was facilitated by emotional affect, whereas memory for an associated context was reduced. In Experiment 2, arousal was manipulated independently of the memoranda, by a threat of shock, whereby encoding trials occurred under conditions of threat or safety. Memory for context was equally impaired by the presence of negative affect, whether induced by threat of shock or a negative item, relative to retrieval of the context of a neutral item in safety. In Experiment 3, participants were presented with neutral and negative items as paired associates, including all combinations of neutral and negative items. The results showed both above effects: compared to a neutral item, memory for the associate of a negative item (a second item here, context in Experiments 1 and 2) is impaired, whereas retrieval of the item itself is enhanced. Our findings suggest that negative affect impairs associative memory while recognition of a negative item is enhanced. They support dual-processing models in which negative affect or stress impairs hippocampal-dependent associative memory while the storage of negative sensory/perceptual representations is spared or even strengthened.

Pulmonary blood volume and transit time in cirrhosis: relation to lung function

DEFF Research Database (Denmark)

Møller, Søren; Burchardt, H; Øgard, CG

2006-01-01

BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... in cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis....... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis...

Alexithymia is related to differences in gray matter volume: a voxel-based morphometry study.

Science.gov (United States)

Ihme, Klas; Dannlowski, Udo; Lichev, Vladimir; Stuhrmann, Anja; Grotegerd, Dominik; Rosenberg, Nicole; Kugel, Harald; Heindel, Walter; Arolt, Volker; Kersting, Anette; Suslow, Thomas

2013-01-23

Alexithymia has been characterized as the inability to identify and describe feelings. Functional imaging studies have revealed that alexithymia is linked to reactivity changes in emotion- and face-processing-relevant brain areas. In this respect, anterior cingulate cortex (ACC), amygdala, anterior insula and fusiform gyrus (FFG) have been consistently reported. However, it remains to be clarified whether alexithymia is also associated with structural differences. Voxel-based morphometry on T1-weighted magnetic resonance images was used to investigate gray matter volume in 17 high alexithymics (HA) and 17 gender-matched low alexithymics (LA), which were selected from a sample of 161 healthy volunteers on basis of the 20-item Toronto Alexithymia Scale. Data were analyzed as statistic parametric maps for the comparisons LA>HA and HA>LA in a priori determined regions of interests (ROIs), i.e., ACC, amygdala, anterior insula and FFG. Moreover, an exploratory whole brain analysis was accomplished. For the contrast LA>HA, significant clusters were detected in the ACC, left amygdala and left anterior insula. Additionally, the whole brain analysis revealed volume differences in the left middle temporal gyrus. No significant differences were found for the comparison HA>LA. Our findings suggest that high compared to low alexithymics show less gray matter volume in several emotion-relevant brain areas. These structural differences might contribute to the functional alterations found in previous imaging studies in alexithymia. Copyright © 2012 Elsevier B.V. All rights reserved.

Medial temporal lobe contributions to cued retrieval of items and contexts.

Science.gov (United States)

Hannula, Deborah E; Libby, Laura A; Yonelinas, Andrew P; Ranganath, Charan

2013-10-01

Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item-context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model-namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item-context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function. Copyright © 2013 Elsevier Ltd. All rights reserved.

Medial Temporal Lobe Contributions to Cued Retrieval of Items and Contexts

Science.gov (United States)

Hannula, Deborah E.; Libby, Laura A.; Yonelinas, Andrew P.; Ranganath, Charan

2013-01-01

Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item-context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model – namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item-context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function. PMID:23466350

Maintenance of item and order information in verbal working memory.

Science.gov (United States)

Camos, Valérie; Lagner, Prune; Loaiza, Vanessa M

2017-09-01

Although verbal recall of item and order information is well-researched in short-term memory paradigms, there is relatively little research concerning item and order recall from working memory. The following study examined whether manipulating the opportunity for attentional refreshing and articulatory rehearsal in a complex span task differently affected the recall of item- and order-specific information of the memoranda. Five experiments varied the opportunity for articulatory rehearsal and attentional refreshing in a complex span task, but the type of recall was manipulated between experiments (item and order, order only, and item only recall). The results showed that impairing attentional refreshing and articulatory rehearsal similarly affected recall regardless of whether the scoring procedure (Experiments 1 and 4) or recall requirements (Experiments 2, 3, and 5) reflected item- or order-specific recall. This implies that both mechanisms sustain the maintenance of item and order information, and suggests that the common cumulative functioning of these two mechanisms to maintain items could be at the root of order maintenance.

Differential item functioning analysis with ordinal logistic regression techniques. DIFdetect and difwithpar.

Science.gov (United States)

Crane, Paul K; Gibbons, Laura E; Jolley, Lance; van Belle, Gerald

2006-11-01

We present an ordinal logistic regression model for identification of items with differential item functioning (DIF) and apply this model to a Mini-Mental State Examination (MMSE) dataset. We employ item response theory ability estimation in our models. Three nested ordinal logistic regression models are applied to each item. Model testing begins with examination of the statistical significance of the interaction term between ability and the group indicator, consistent with nonuniform DIF. Then we turn our attention to the coefficient of the ability term in models with and without the group term. If including the group term has a marked effect on that coefficient, we declare that it has uniform DIF. We examined DIF related to language of test administration in addition to self-reported race, Hispanic ethnicity, age, years of education, and sex. We used PARSCALE for IRT analyses and STATA for ordinal logistic regression approaches. We used an iterative technique for adjusting IRT ability estimates on the basis of DIF findings. Five items were found to have DIF related to language. These same items also had DIF related to other covariates. The ordinal logistic regression approach to DIF detection, when combined with IRT ability estimates, provides a reasonable alternative for DIF detection. There appear to be several items with significant DIF related to language of test administration in the MMSE. More attention needs to be paid to the specific criteria used to determine whether an item has DIF, not just the technique used to identify DIF.

Highway Safety Program Manual: Volume 8: Alcohol in Relation to Highway Safety.

Science.gov (United States)

National Highway Traffic Safety Administration (DOT), Washington, DC.

Volume 8 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) concentrates on alcohol in relation to highway safety. The purpose and objectives of the alcohol program are outlined. Federal authority in the area of highway safety and general policies regarding…

The relative volume growth of minimal submanifolds

DEFF Research Database (Denmark)

Markvorsen, Steen; Palmer, V.

2002-01-01

The volume growth of certain well-defined subsets of minimal submanifolds in riemannian spaces are compared with the volume growth of balls and spheres ill space forms of constant curvature.......The volume growth of certain well-defined subsets of minimal submanifolds in riemannian spaces are compared with the volume growth of balls and spheres ill space forms of constant curvature....

QA in the procurement of items and services

International Nuclear Information System (INIS)

Wilhelm, H.

1980-01-01

Procurement of items and services is one of the important elements during the design and construction of Nuclear Power Plants. The purchaser has to establish and implement controls over the procurement process to ensure that the quality criteria, quality level and other quality requirements specified for the particuliar item or service are taken into account. The effect on safety of an error in service or the malfunction of an item is the most important factor to be considered in determining the extent of quality assurance efforts. A typical example of a procurement process will be demonstrated for safety related mechanical components. (orig./RW)

The impact of item order on ratings of cancer risk perception.

Science.gov (United States)

Taylor, Kathryn L; Shelby, Rebecca A; Schwartz, Marc D; Ackerman, Josh; LaSalle, V Holland; Gelmann, Edward P; McGuire, Colleen

2002-07-01

Although perceived risk is central to most theories of health behavior, there is little consensus on its measurement with regard to item wording, response set, or the number of items to include. In a methodological assessment of perceived risk, we assessed the impact of changing the order of three commonly used perceived risk items: quantitative personal risk, quantitative population risk, and comparative risk. Participants were 432 men and women enrolled in an ancillary study of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Three groups of consecutively enrolled participants responded to the three items in one of three question orders. Results indicated that item order was related to the perceived risk ratings of both ovarian (P Perceptions of risk were significantly lower when the comparative rating was made first. The findings suggest that compelling participants to consider their own risk relative to the risk of others results in lower ratings of perceived risk. Although the use of multiple items may provide more information than when only a single method is used, different conclusions may be reached depending on the context in which an item is assessed.

Hippocampal volume in relation to clinical and cognitive outcome after electroconvulsive therapy in depression.

Science.gov (United States)

Nordanskog, P; Larsson, M R; Larsson, E-M; Johanson, A

2014-04-01

In a previous magnetic resonance imaging (MRI) study, we found a significant increase in hippocampal volume immediately after electroconvulsive therapy (ECT) in patients with depression. The aim of this study was to evaluate hippocampal volume up to 1 year after ECT and investigate its possible relation to clinical and cognitive outcome. Clinical and cognitive outcome in 12 in-patients with depression receiving antidepressive pharmacological treatment referred for ECT were investigated with the Montgomery-Asberg Depression Rating Scale (MADRS) and a broad neuropsychological test battery within 1 week before and after ECT. The assessments were repeated 6 and 12 months after baseline in 10 and seven of these patients, respectively. Hippocampal volumes were measured on all four occasions with 3 Tesla MRI. Hippocampal volume returned to baseline during the follow-up period of 6 months. Neither the significant antidepressant effect nor the significant transient decrease in executive and verbal episodic memory tests after ECT could be related to changes in hippocampal volume. No persistent cognitive side effects were observed 1 year after ECT. The immediate increase in hippocampal volume after ECT is reversible and is not related to clinical or cognitive outcome. © 2013 The Authors. Acta Psychiatrica Scandinavica published by John Wiley & Sons Ltd.

Differential item functioning magnitude and impact measures from item response theory models.

Science.gov (United States)

Kleinman, Marjorie; Teresi, Jeanne A

2016-01-01

Measures of magnitude and impact of differential item functioning (DIF) at the item and scale level, respectively are presented and reviewed in this paper. Most measures are based on item response theory models. Magnitude refers to item level effect sizes, whereas impact refers to differences between groups at the scale score level. Reviewed are magnitude measures based on group differences in the expected item scores and impact measures based on differences in the expected scale scores. The similarities among these indices are demonstrated. Various software packages are described that provide magnitude and impact measures, and new software presented that computes all of the available statistics conveniently in one program with explanations of their relationships to one another.

MACULAR CHOROIDAL VOLUME CHANGES AFTER INTRAVITREAL BEVACIZUMAB FOR EXUDATIVE AGE-RELATED MACULAR DEGENERATION.

Science.gov (United States)

Palkovits, Stefan; Seidel, Gerald; Pertl, Laura; Malle, Eva M; Hausberger, Silke; Makk, Johanna; Singer, Christoph; Osterholt, Julia; Herzog, Sereina A; Haas, Anton; Weger, Martin

2017-12-01

To evaluate the effect of intravitreal bevacizumab on the macular choroidal volume and the subfoveal choroidal thickness in treatment naïve eyes with exudative age-related macular degeneration. The macular choroidal volume and the subfoveal choroidal thickness were measured using enhanced depth imaging optical coherence tomography. After a screening examination, each patient received 3 monthly intravitreal injections of 1.25 mg bevacizumab. One month after the third injection was a final assessment. Forty-seven patients with a mean age of 80 ± 6.4 years were included. The macular choroidal volume decreased significantly from median 4.1 mm (interquartile range 3.4-5.9) to median 3.9 mm (interquartile range 3.1-5.6) between the baseline and final examination (difference -0.46 mm, 95% confidence interval: -0.57 to 0.35, P macular choroidal volume at baseline and subfoveal choroidal thickness at baseline were not associated with the response to treatment. The macular choroidal volume and the subfoveal choroidal thickness decreased significantly after 3 monthly bevacizumab injections for exudative age-related macular degeneration.

ITEM LEVEL DIAGNOSTICS AND MODEL - DATA FIT IN ITEM ...

African Journals Online (AJOL)

Global Journal

Item response theory (IRT) is a framework for modeling and analyzing item response ... data. Though, there is an argument that the evaluation of fit in IRT modeling has been ... National Council on Measurement in Education ... model data fit should be based on three types of ... prediction should be assessed through the.

Infants’ Visual Recognition Memory for a Series of Categorically Related Items

Science.gov (United States)

Oakes, Lisa M.; Kovack-Lesh, Kristine A.

2013-01-01

Six-month-old infants' ("N" = 168) memory for individual items in a categorized list (e.g., images of dogs or cats) was examined to investigate the interactions between visual recognition memory, working memory, and categorization. In Experiments 1 and 2, infants were familiarized with six different cats or dogs, presented one at a time…

Pulmonary blood volume and transit time in cirrhosis: relation to lung function

DEFF Research Database (Denmark)

Møller, Søren; Burchardt, H; Øgard, CG

2006-01-01

BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis......, in the controls, Pvolume...

SHIPPING OF RADIOACTIVE ITEMS

CERN Multimedia

TIS/RP Group

2001-01-01

The TIS-RP group informs users that shipping of small radioactive items is normally guaranteed within 24 hours from the time the material is handed in at the TIS-RP service. This time is imposed by the necessary procedures (identification of the radionuclides, determination of dose rate, preparation of the package and related paperwork). Large and massive objects require a longer procedure and will therefore take longer.

Binary classification of items of interest in a repeatable process

Science.gov (United States)

Abell, Jeffrey A.; Spicer, John Patrick; Wincek, Michael Anthony; Wang, Hui; Chakraborty, Debejyo

2014-06-24

A system includes host and learning machines in electrical communication with sensors positioned with respect to an item of interest, e.g., a weld, and memory. The host executes instructions from memory to predict a binary quality status of the item. The learning machine receives signals from the sensor(s), identifies candidate features, and extracts features from the candidates that are more predictive of the binary quality status relative to other candidate features. The learning machine maps the extracted features to a dimensional space that includes most of the items from a passing binary class and excludes all or most of the items from a failing binary class. The host also compares the received signals for a subsequent item of interest to the dimensional space to thereby predict, in real time, the binary quality status of the subsequent item of interest.

An evaluation of the brief symptom inventory-18 using item response theory: which items are most strongly related to psychological distress?

NARCIS (Netherlands)

Meijer, R.R.; de Vries, Rivka M.; van Bruggen, Vincent

2011-01-01

The psychometric structure of the Brief Symptom Inventory–18 (BSI-18; Derogatis, 2001) was investigated using Mokken scaling and parametric item response theory. Data of 487 outpatients, 266 students, and 207 prisoners were analyzed. Results of the Mokken analysis indicated that the BSI-18 formed a

An Evaluation of the Brief Symptom Inventory-18 Using Item Response Theory : Which Items Are Most Strongly Related to Psychological Distress?

NARCIS (Netherlands)

Meijer, Rob R.; de Vries, Rivka M.; van Bruggen, Vincent

The psychometric structure of the Brief Symptom Inventory-18 (BSI-18; Derogatis, 2001) was investigated using Mokken scaling and parametric item response theory. Data of 487 outpatients, 266 students, and 207 prisoners were analyzed. Results of the Mokken analysis indicated that the BSI-18 formed a

Comparison of uncertainties related to standardization of urine samples with volume and creatinine concentration

DEFF Research Database (Denmark)

Garde, Anne Helene; Hansen, Ase Marie; Kristiansen, Jesper

2004-01-01

When measuring biomarkers in urine, volume (and time) or concentration of creatinine are both accepted methods of standardization for diuresis. Both types of standardization contribute uncertainty to the final result. The aim of the present paper was to compare the uncertainty introduced when usi...... increase in convenience for the participants, when collecting small volumes rather than complete 24 h samples....... the two types of standardization on 24 h samples from healthy individuals. Estimates of uncertainties were based on results from the literature supplemented with data from our own studies. Only the difference in uncertainty related to the two standardization methods was evaluated. It was found...... that the uncertainty associated with creatinine standardization (19-35%) was higher than the uncertainty related to volume standardization (up to 10%, when not correcting for deviations from 24 h) for 24 h urine samples. However, volume standardization introduced an average bias of 4% due to missed volumes...

Method and apparatus for probing relative volume fractions

Science.gov (United States)

Jandrasits, Walter G.; Kikta, Thomas J.

1998-01-01

A relative volume fraction probe particularly for use in a multiphase fluid system includes two parallel conductive paths defining therebetween a sample zone within the system. A generating unit generates time varying electrical signals which are inserted into one of the two parallel conductive paths. A time domain reflectometer receives the time varying electrical signals returned by the second of the two parallel conductive paths and, responsive thereto, outputs a curve of impedance versus distance. An analysis unit then calculates the area under the curve, subtracts the calculated area from an area produced when the sample zone consists entirely of material of a first fluid phase, and divides this calculated difference by the difference between an area produced when the sample zone consists entirely of material of the first fluid phase and an area produced when the sample zone consists entirely of material of a second fluid phase. The result is the volume fraction.

Detection of advance item knowledge using response times in computer adaptive testing

NARCIS (Netherlands)

Meijer, R.R.; Sotaridona, Leonardo

2006-01-01

We propose a new method for detecting item preknowledge in a CAT based on an estimate of “effective response time” for each item. Effective response time is defined as the time required for an individual examinee to answer an item correctly. An unusually short response time relative to the expected

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.

Improving a measure of mobility-related fatigue (the mobility-tiredness scale) by establishing item intensity

DEFF Research Database (Denmark)

Fieo, Robert A; Mortensen, Erik L; Rantanen, Taina

2013-01-01

To improve the construct validity of self-reported fatigue by establishing a formal hierarchy of scale items and to determine whether such a hierarchy could be maintained across time (aged 75-80), sex, and nationality.......To improve the construct validity of self-reported fatigue by establishing a formal hierarchy of scale items and to determine whether such a hierarchy could be maintained across time (aged 75-80), sex, and nationality....

Analyzing force concept inventory with item response theory

Science.gov (United States)

Wang, Jing; Bao, Lei

2010-10-01

Item response theory is a popular assessment method used in education. It rests on the assumption of a probability framework that relates students' innate ability and their performance on test questions. Item response theory transforms students' raw test scores into a scaled proficiency score, which can be used to compare results obtained with different test questions. The scaled score also addresses the issues of ceiling effects and guessing, which commonly exist in quantitative assessment. We used item response theory to analyze the force concept inventory (FCI). Our results show that item response theory can be useful for analyzing physics concept surveys such as the FCI and produces results about the individual questions and student performance that are beyond the capability of classical statistics. The theory yields detailed measurement parameters regarding the difficulty, discrimination features, and probability of correct guess for each of the FCI questions.

Work-related stress assessed by a text message single-item stress question.

Science.gov (United States)

Arapovic-Johansson, B; Wåhlin, C; Kwak, L; Björklund, C; Jensen, I

2017-12-02

Given the prevalence of work stress-related ill-health in the Western world, it is important to find cost-effective, easy-to-use and valid measures which can be used both in research and in practice. To examine the validity and reliability of the single-item stress question (SISQ), distributed weekly by short message service (SMS) and used for measurement of work-related stress. The convergent validity was assessed through associations between the SISQ and subscales of the Job Demand-Control-Support model, the Effort-Reward Imbalance model and scales measuring depression, exhaustion and sleep. The predictive validity was assessed using SISQ data collected through SMS. The reliability was analysed by the test-retest procedure. Correlations between the SISQ and all the subscales except for job strain and esteem reward were significant, ranging from -0.186 to 0.627. The SISQ could also predict sick leave, depression and exhaustion at 12-month follow-up. The analysis on reliability revealed a satisfactory stability with a weighted kappa between 0.804 and 0.868. The SISQ, administered through SMS, can be used for the screening of stress levels in a working population. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Forced-Choice Assessment of Work-Related Maladaptive Personality Traits: Preliminary Evidence From an Application of Thurstonian Item Response Modeling.

Science.gov (United States)

Guenole, Nigel; Brown, Anna A; Cooper, Andrew J

2018-06-01

This article describes an investigation of whether Thurstonian item response modeling is a viable method for assessment of maladaptive traits. Forced-choice responses from 420 working adults to a broad-range personality inventory assessing six maladaptive traits were considered. The Thurstonian item response model's fit to the forced-choice data was adequate, while the fit of a counterpart item response model to responses to the same items but arranged in a single-stimulus design was poor. Monotrait heteromethod correlations indicated corresponding traits in the two formats overlapped substantially, although they did not measure equivalent constructs. A better goodness of fit and higher factor loadings for the Thurstonian item response model, coupled with a clearer conceptual alignment to the theoretical trait definitions, suggested that the single-stimulus item responses were influenced by biases that the independent clusters measurement model did not account for. Researchers may wish to consider forced-choice designs and appropriate item response modeling techniques such as Thurstonian item response modeling for personality questionnaire applications in industrial psychology, especially when assessing maladaptive traits. We recommend further investigation of this approach in actual selection situations and with different assessment instruments.

Instructional Topics in Educational Measurement (ITEMS) Module: Using Automated Processes to Generate Test Items

Science.gov (United States)

Gierl, Mark J.; Lai, Hollis

2013-01-01

Changes to the design and development of our educational assessments are resulting in the unprecedented demand for a large and continuous supply of content-specific test items. One way to address this growing demand is with automatic item generation (AIG). AIG is the process of using item models to generate test items with the aid of computer…

A 67-Item Stress Resilience item bank showing high content validity was developed in a psychosomatic sample.

Science.gov (United States)

Obbarius, Nina; Fischer, Felix; Obbarius, Alexander; Nolte, Sandra; Liegl, Gregor; Rose, Matthias

2018-04-10

To develop the first item bank to measure Stress Resilience (SR) in clinical populations. Qualitative item development resulted in an initial pool of 131 items covering a broad theoretical SR concept. These items were tested in n=521 patients at a psychosomatic outpatient clinic. Exploratory and Confirmatory Factor Analysis (CFA), as well as other state-of-the-art item analyses and IRT were used for item evaluation and calibration of the final item bank. Out of the initial item pool of 131 items, we excluded 64 items (54 factor loading .3, 2 non-discriminative Item Response Curves, 4 Differential Item Functioning). The final set of 67 items indicated sufficient model fit in CFA and IRT analyses. Additionally, a 10-item short form with high measurement precision (SE≤.32 in a theta range between -1.8 and +1.5) was derived. Both the SR item bank and the SR short form were highly correlated with an existing static legacy tool (Connor-Davidson Resilience Scale). The final SR item bank and 10-item short form showed good psychometric properties. When further validated, they will be ready to be used within a framework of Computer-Adaptive Tests for a comprehensive assessment of the Stress-Construct. Copyright © 2018. Published by Elsevier Inc.

Teoria da Resposta ao Item Teoria de la respuesta al item Item response theory

Directory of Open Access Journals (Sweden)

Eutalia Aparecida Candido de Araujo

2009-12-01

Full Text Available A preocupação com medidas de traços psicológicos é antiga, sendo que muitos estudos e propostas de métodos foram desenvolvidos no sentido de alcançar este objetivo. Entre os trabalhos propostos, destaca-se a Teoria da Resposta ao Item (TRI que, a princípio, veio completar limitações da Teoria Clássica de Medidas, empregada em larga escala até hoje na medida de traços psicológicos. O ponto principal da TRI é que ela leva em consideração o item particularmente, sem relevar os escores totais; portanto, as conclusões não dependem apenas do teste ou questionário, mas de cada item que o compõe. Este artigo propõe-se a apresentar esta Teoria que revolucionou a teoria de medidas.La preocupación con las medidas de los rasgos psicológicos es antigua y muchos estudios y propuestas de métodos fueron desarrollados para lograr este objetivo. Entre estas propuestas de trabajo se incluye la Teoría de la Respuesta al Ítem (TRI que, en principio, vino a completar las limitaciones de la Teoría Clásica de los Tests, ampliamente utilizada hasta hoy en la medida de los rasgos psicológicos. El punto principal de la TRI es que se tiene en cuenta el punto concreto, sin relevar las puntuaciones totales; por lo tanto, los resultados no sólo dependen de la prueba o cuestionario, sino que de cada ítem que lo compone. En este artículo se propone presentar la Teoría que revolucionó la teoría de medidas.The concern with measures of psychological traits is old and many studies and proposals of methods were developed to achieve this goal. Among these proposed methods highlights the Item Response Theory (IRT that, in principle, came to complete limitations of the Classical Test Theory, which is widely used until nowadays in the measurement of psychological traits. The main point of IRT is that it takes into account the item in particular, not relieving the total scores; therefore, the findings do not only depend on the test or questionnaire

Are great apes able to reason from multi-item samples to populations of food items?

Science.gov (United States)

Eckert, Johanna; Rakoczy, Hannes; Call, Josep

2017-10-01

Inductive learning from limited observations is a cognitive capacity of fundamental importance. In humans, it is underwritten by our intuitive statistics, the ability to draw systematic inferences from populations to randomly drawn samples and vice versa. According to recent research in cognitive development, human intuitive statistics develops early in infancy. Recent work in comparative psychology has produced first evidence for analogous cognitive capacities in great apes who flexibly drew inferences from populations to samples. In the present study, we investigated whether great apes (Pongo abelii, Pan troglodytes, Pan paniscus, Gorilla gorilla) also draw inductive inferences in the opposite direction, from samples to populations. In two experiments, apes saw an experimenter randomly drawing one multi-item sample from each of two populations of food items. The populations differed in their proportion of preferred to neutral items (24:6 vs. 6:24) but apes saw only the distribution of food items in the samples that reflected the distribution of the respective populations (e.g., 4:1 vs. 1:4). Based on this observation they were then allowed to choose between the two populations. Results show that apes seemed to make inferences from samples to populations and thus chose the population from which the more favorable (4:1) sample was drawn in Experiment 1. In this experiment, the more attractive sample not only contained proportionally but also absolutely more preferred food items than the less attractive sample. Experiment 2, however, revealed that when absolute and relative frequencies were disentangled, apes performed at chance level. Whether these limitations in apes' performance reflect true limits of cognitive competence or merely performance limitations due to accessory task demands is still an open question. © 2017 Wiley Periodicals, Inc.

MRI-Based Measurement of Hippocampal Volume in Patients With Combat-Related Posttraumatic Stress Disorder

Science.gov (United States)

Bremner, J. Douglas; Randall, Penny; Scott, Tammy M.; Bronen, Richard A.; Seibyl, John P.; Southwick, Steven M.; Delaney, Richard C.; McCarthy, Gregory; Charney, Dennis S.; Innis, Robert B.

2011-01-01

Objective Studies in nonhuman primates suggest that high levels of cortisol associated with stress have neurotoxic effects on the hippocampus, a brain structure involved in memory. The authors previously showed that patients with combat-related posttraumatic stress disorder (PTSD) had deficits in short-term memory. The purpose of this study was to compare the hippocampal volume of patients with PTSD to that of subjects without psychiatric disorder. Method Magnetic resonance imaging was used to measure the volume of the hippocampus in 26 Vietnam combat veterans with PTSD and 22 comparison subjects selected to be similar to the patients in age, sex, race, years of education, socioeconomic status, body size, and years of alcohol abuse. Results The PTSD patients had a statistically significant 8% smaller right hippocampal volume relative to that of the comparison subjects, but there was no difference in the volume of other brain regions (caudate and temporal lobe). Deficits in short-term verbal memory as measured with the Wechsler Memory Scale were associated with smaller right hippocampal volume in the PTSD patients only. Conclusions These findings are consistent with a smaller right hippocampal volume in PTSD that is associated with functional deficits in verbal memory. PMID:7793467

Using an FSDS-R Item to Screen for Sexually Related Distress: A MsFLASH Analysis

Science.gov (United States)

Carpenter, Janet S; Reed, Susan D; Guthrie, Katherine A; Larson, Joseph C; Newton, Katherine M; Lau, R Jane; Learman, Lee A; Shifren, Jan L

2015-01-01

Introduction The Female Sexual Distress Scale-Revised (FSDS-R) was created and validated to assess distress associated with impaired sexual function, but it is lengthy for use in clinical practice and research when assessing sexual function is not a primary objective. Aim The study aims to evaluate whether a single item from the FSDS-R could be identified to use to screen midlife women for bothersome diminution in sexual function based on three criteria: (i) highly correlated with total scores; (ii) correlated with commonly assessed domains of female sexual functioning; and (iii) able to differentiate between women reporting high and low sexual concerns during the prior month. Methods Data from 93 midlife women were collected by the Menopause Strategies Finding Lasting Answers to Symptoms and Health (MsFLASH) research network. Main Outcome Measures Women completed the FSDS-R, Female Sexual Function Index (FSFI), and Menopausal Quality of Life Scale (MENQOL). Those who reported a change in the past month on the MENQOL sexual were categorized into a high sexual concerns group, while all others were categorized into a low sexual concerns group. Results Women were an average of 54.6 years old (SD 3.1) and mostly Caucasian (77.4%), college educated (60.2%), married/living as married (64.5%), and postmenopausal (79.6%). The FSDS-R item number 1 “Distressed about sex life” was: (i) highly correlated with FSDS-R total scores (r = 0.90); (ii) moderately correlated with FSFI total scores (r = −0.38) and FSFI desire (r = −0.37) and satisfaction domains (r = −0.40); and (iii) showed one of the largest mean differences between high and low sexual concerns groups (P Guthrie KA, Larson JC, Newton KM, Lau RJ, Learman LA, and Shifren JL. Using an FSDS-R item to screen for sexually related distress: A MsFLASH analysis. Sex Med 2015;3:7–13. PMID:25844170

GPU v. B and W lawsuit review and its effect on TMI-1 (Docket 50-289). Volume 2. Appendices

International Nuclear Information System (INIS)

1983-09-01

Volume II of the GPU v. B and W lawsuit review contains four appendices supporting the review of the GPU v. B and W lawsuit discussed in Volume I of this report. As outlined in the Background section of Volume I under (3) Review Method Utilized by the Staff, the GPU v. B and W lawsuit review was partitioned into 10 categories. The 154 certification items and the 19 long-term actions (hearing items or restart issues) resulting from Commission Orders and the hearing process were each placed in one or more of the 10 categories. These appendices contain the hearing items by category; lawsuit record by category; category location matrix for lawsuit record; and uncategorized lawsuit record

32 CFR 507.17 - Procurement and wear of heraldic items.

Science.gov (United States)

2010-07-01

... controlled heraldic items, when authorized by local procurement procedures, may forward a sample insignia to... 32 National Defense 3 2010-07-01 2010-07-01 true Procurement and wear of heraldic items. 507.17... AUTHORITIES AND PUBLIC RELATIONS MANUFACTURE AND SALE OF DECORATIONS, MEDALS, BADGES, INSIGNIA, COMMERCIAL USE...

Validation of a 15-item care-related regret coping scale for health-care professionals (RCS-HCP).

Science.gov (United States)

Courvoisier, Delphine Sophie; Cullati, Stephane; Ouchi, Rieko; Schmidt, Ralph Eric; Haller, Guy; Chopard, Pierre; Agoritsas, Thomas; Perneger, Thomas V

2014-01-01

Coping with difficult care-related situations is a common challenge for health-care professionals. How these professionals deal with the regrets they may experience following one of the many decisions and interventions they must make every day can have an impact on their own health and quality of life, and also on their patient care practices. To identify professionals most at need for extra support, development and validation of a tool measuring coping style are needed. We performed a survey of physicians and nurses of a French-speaking University hospital; 469 health-care professionals responded to the survey, and 175 responded to the same survey one-month later. Regret was assessed with the regret coping scale developed for this study, self-report questions on the frequency of regretted situations and the intensity of regret. Construct validity was assessed using measures of health-care professionals' quality of life (including job and life satisfaction, and self-reported health) as well as sleep problems and depression. Based on factor analysis and item response analysis, the initial 31-item scale was shortened to 15 items, which measured three types of strategies: problem-focused strategies (i.e., trying to find solutions, talking to colleagues) and two types of emotion-focused strategies, A (i.e., self-blame, rumination) and B (e.g., acceptance, emotional distance). All subscales showed high internal consistency (α >0.85). Overall, as expected, problem-focused and emotion-focused B strategies correlated with higher quality of life, fewer sleep problems and less depression, and emotion-focused A strategies showed the opposite pattern. The regret coping scale (RCS-HCP) is a valid and reliable measure of coping abilities of hospital-based health-care professionals.

Image-guided radiotherapy of bladder cancer: bladder volume variation and its relation to margins

DEFF Research Database (Denmark)

Muren, Ludvig; Redpath, Anthony Thomas; Lord, Hannah

2007-01-01

: The correlation between the relative bladder volume (RBV, defined as repeat scan volume/planning scan volume) and the margins required to account for internal motion was first studied using a series of 20 bladder cancer patients with weekly repeat CT scanning during treatment. Both conformal RT (CRT) and IGRT......BACKGROUND AND PURPOSE: To control and account for bladder motion is a major challenge in radiotherapy (RT) of bladder cancer. This study investigates the relation between bladder volume variation and margins in conformal and image-guided RT (IGRT) for this disease. MATERIALS AND METHODS...... these patients were given fluid intake restrictions on alternating weeks during treatment. RESULTS: IGRT gave the strongest correlation between the RBV and margin size (R(2)=0.75; p10mm were required in only 1% of the situations when the RBV1, whereas isotropic margins >10...

Item response theory scoring and the detection of curvilinear relationships.

Science.gov (United States)

Carter, Nathan T; Dalal, Dev K; Guan, Li; LoPilato, Alexander C; Withrow, Scott A

2017-03-01

Psychologists are increasingly positing theories of behavior that suggest psychological constructs are curvilinearly related to outcomes. However, results from empirical tests for such curvilinear relations have been mixed. We propose that correctly identifying the response process underlying responses to measures is important for the accuracy of these tests. Indeed, past research has indicated that item responses to many self-report measures follow an ideal point response process-wherein respondents agree only to items that reflect their own standing on the measured variable-as opposed to a dominance process, wherein stronger agreement, regardless of item content, is always indicative of higher standing on the construct. We test whether item response theory (IRT) scoring appropriate for the underlying response process to self-report measures results in more accurate tests for curvilinearity. In 2 simulation studies, we show that, regardless of the underlying response process used to generate the data, using the traditional sum-score generally results in high Type 1 error rates or low power for detecting curvilinearity, depending on the distribution of item locations. With few exceptions, appropriate power and Type 1 error rates are achieved when dominance-based and ideal point-based IRT scoring are correctly used to score dominance and ideal point response data, respectively. We conclude that (a) researchers should be theory-guided when hypothesizing and testing for curvilinear relations; (b) correctly identifying whether responses follow an ideal point versus dominance process, particularly when items are not extreme is critical; and (c) IRT model-based scoring is crucial for accurate tests of curvilinearity. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Effects of Emotional Intelligence (EI Items Education on Job Related Stress in Physicians and Nurses who Work in Intensive Care Units

Directory of Open Access Journals (Sweden)

Kh Nooryan

2011-12-01

Full Text Available Background & Aim: Intensive care units (ICUs are recognized as stressful environments. The objective of this study was to determine the effects of emotional intelligence education items on job related stress on physicians and nurses who work in intensive care units at hospitals of Yerevan, Armenia. Methods: A interventional study design was implemented with 106 registered hospital physicians and nurses, who were widely distributed all the way through. Case group was taught about 15 E.I items. For data collection, the 20-question Berger situational (overt anxiety questionnaire, the 20-item personality (covert anxiety questionnaire, and the Bar-on emotional intelligence questionnaire with 133 questions were used. Statistical descriptive methods, chi-square (X2 and t-tests were used to analyze data. Results: The research achievements revealed that the average score of the case group`s situational anxiety was 46.59 before intervention, which decreased to 39.95 after the training of the items of emotional intelligence. The average score of situational anxiety of control group was 44.32 before intervention which increased to 44.76 after examination. There was a meaningful statistical difference between case and control group after education of emotional intelligence`s items (p=0.001. Conclusion: Results of the current study showed that physicians and nurses experience high level of stress. The ability to effectively deal with emotion intelligence and emotional information in the workplace assists employees in coping with occupational stress and should be developed in stress managing trainings.

Validity and Reliability of the 8-Item Work Limitations Questionnaire.

Science.gov (United States)

Walker, Timothy J; Tullar, Jessica M; Diamond, Pamela M; Kohl, Harold W; Amick, Benjamin C

2017-12-01

Purpose To evaluate factorial validity, scale reliability, test-retest reliability, convergent validity, and discriminant validity of the 8-item Work Limitations Questionnaire (WLQ) among employees from a public university system. Methods A secondary analysis using de-identified data from employees who completed an annual Health Assessment between the years 2009-2015 tested research aims. Confirmatory factor analysis (CFA) (n = 10,165) tested the latent structure of the 8-item WLQ. Scale reliability was determined using a CFA-based approach while test-retest reliability was determined using the intraclass correlation coefficient. Convergent/discriminant validity was tested by evaluating relations between the 8-item WLQ with health/performance variables for convergent validity (health-related work performance, number of chronic conditions, and general health) and demographic variables for discriminant validity (gender and institution type). Results A 1-factor model with three correlated residuals demonstrated excellent model fit (CFI = 0.99, TLI = 0.99, RMSEA = 0.03, and SRMR = 0.01). The scale reliability was acceptable (0.69, 95% CI 0.68-0.70) and the test-retest reliability was very good (ICC = 0.78). Low-to-moderate associations were observed between the 8-item WLQ and the health/performance variables while weak associations were observed between the demographic variables. Conclusions The 8-item WLQ demonstrated sufficient reliability and validity among employees from a public university system. Results suggest the 8-item WLQ is a usable alternative for studies when the more comprehensive 25-item WLQ is not available.

An Evaluation of the Brief Symptom Inventory-18 Using Item Response Theory: Which Items Are Most Strongly Related to Psychological Distress?

Science.gov (United States)

Meijer, Rob R.; de Vries, Rivka M.; van Bruggen, Vincent

2011-01-01

The psychometric structure of the Brief Symptom Inventory-18 (BSI-18; Derogatis, 2001) was investigated using Mokken scaling and parametric item response theory. Data of 487 outpatients, 266 students, and 207 prisoners were analyzed. Results of the Mokken analysis indicated that the BSI-18 formed a strong Mokken scale for outpatients and…

Three Modeling Applications to Promote Automatic Item Generation for Examinations in Dentistry.

Science.gov (United States)

Lai, Hollis; Gierl, Mark J; Byrne, B Ellen; Spielman, Andrew I; Waldschmidt, David M

2016-03-01

Test items created for dentistry examinations are often individually written by content experts. This approach to item development is expensive because it requires the time and effort of many content experts but yields relatively few items. The aim of this study was to describe and illustrate how items can be generated using a systematic approach. Automatic item generation (AIG) is an alternative method that allows a small number of content experts to produce large numbers of items by integrating their domain expertise with computer technology. This article describes and illustrates how three modeling approaches to item content-item cloning, cognitive modeling, and image-anchored modeling-can be used to generate large numbers of multiple-choice test items for examinations in dentistry. Test items can be generated by combining the expertise of two content specialists with technology supported by AIG. A total of 5,467 new items were created during this study. From substitution of item content, to modeling appropriate responses based upon a cognitive model of correct responses, to generating items linked to specific graphical findings, AIG has the potential for meeting increasing demands for test items. Further, the methods described in this study can be generalized and applied to many other item types. Future research applications for AIG in dental education are discussed.

Perceived Stress Is Differentially Related to Hippocampal Subfield Volumes among Older Adults.

Directory of Open Access Journals (Sweden)

Molly E Zimmerman

Full Text Available Chronic exposure to stress has been shown to impact a wide range of health-related outcomes in older adults. Despite extensive animal literature revealing deleterious effects of biological markers of stress on the dentate gyrus subfield of the hippocampus, links between hippocampal subfields and psychological stress have not been studied in humans. This study examined the relationship between perceived stress and hippocampal subfield volumes among racially/ethnically diverse older adults.Between July 2011 and March 2014, 116 nondemented participants were consecutively drawn from the Einstein Aging Study, an ongoing community-based sample of individuals over the age of 70 residing in Bronx, New York. All participants completed the Perceived Stress Scale, Geriatric Depression Scale, and underwent 3.0 T MRI. FreeSurfer was used to derive total hippocampal volume, hippocampal subfield volumes (CA1, CA2/CA3, CA4/Dentate Gyrus (CA4/DG, and subiculum, entorhinal cortex volume, whole brain volume, and total intracranial volume.Linear regression analyses revealed that higher levels of perceived stress were associated with smaller total hippocampal volume (β = -0.20, t = -2.40, p = 0.02, smaller CA2/CA3 volumes (β = -0.18, t = -2.24, p = 0.03 and smaller CA4/DG volumes (β = -0.19, t = -2.28, p = 0.03 after controlling for total intracranial volume, age, gender, and race. These findings remained unchanged after removal of individuals with clinically significant symptoms of depression.Our findings provide evidence of a relationship between a direct indicator of psychological stress and specific hippocampal subfield volumes in elderly individuals. These results highlight the importance of clinical screening for chronic stress in otherwise healthy older adults.

Are urine flow-volume nomograms developed on Caucasian men optimally applicable for Indian men? Need for appraisal of flow-volume relations in local population

Directory of Open Access Journals (Sweden)

Mayank M Agarwal

2010-01-01

Full Text Available Introduction : Flow-volume nomograms and volume-corrected flow-rates (cQ are tools to correct uroflow rates (Q with varied voided volumes (VV of urine. We investigated the applicability of the available nomograms in our local population. Materials and Methods : Raw data of our previous study on variation in Q with voiding position (standing, sitting, and squatting in healthy adult men was reanalyzed. Additionally, the departmental urodynamic database of the last four years was searched for uroflow data of men with voiding symptoms (International Prostatic Symptom Score (IPSS > 7 and global quality of life score >2. These results were projected on the Liverpool and Siroky nomograms for men. The Q-VV relations were statistically analyzed using curve-estimation regression method to examine the current definition of corrected maximum flow rate (Qmax. Results : We found a cubic relation between Q and VV; based on this we developed novel equation for cQ [cQ=Q/(VV 1/3 ] and novel confidence-limit flow-volume nomograms. The imaginary 16 th percentile line of Liverpool nomogram, -1 standard-deviation line of Siroky nomogram and lower 68% confidence-limit line of our nomogram had sensitivity of 96.2%, 100% and 89.3%, and specificity of 75.3% 69.3% and 86.0%, respectively for Qmax-VV relations. Corresponding values for average flow rate (Qave-volume relations were 96.2%, 100% and 94.6%, and 75.2%, 50.4% and 86.0%, respectively. The area under curve of the receiver operating characteristics (ROC curve for cQmax and cQave was 0.954 and 0.965, respectively, suggesting significantly higher discriminatory power than chance (P = 0.0001. Conclusion : Flow-volume nomograms developed on Caucasian population may not be optimally applicable to the Indian population. We introduce flow-volume nomograms and cQ, which have high sensitivity and specificity.

24 CFR 200.926a - Residential building code comparison items.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Residential building code comparison items. 200.926a Section 200.926a Housing and Urban Development Regulations Relating to Housing and... § 200.926a Residential building code comparison items. HUD will review each local and State code...

Selecting Items for Criterion-Referenced Tests.

Science.gov (United States)

Mellenbergh, Gideon J.; van der Linden, Wim J.

1982-01-01

Three item selection methods for criterion-referenced tests are examined: the classical theory of item difficulty and item-test correlation; the latent trait theory of item characteristic curves; and a decision-theoretic approach for optimal item selection. Item contribution to the standardized expected utility of mastery testing is discussed. (CM)

Geriatric Anxiety Scale: item response theory analysis, differential item functioning, and creation of a ten-item short form (GAS-10).

Science.gov (United States)

Mueller, Anne E; Segal, Daniel L; Gavett, Brandon; Marty, Meghan A; Yochim, Brian; June, Andrea; Coolidge, Frederick L

2015-07-01

The Geriatric Anxiety Scale (GAS; Segal et al. (Segal, D. L., June, A., Payne, M., Coolidge, F. L. and Yochim, B. (2010). Journal of Anxiety Disorders, 24, 709-714. doi:10.1016/j.janxdis.2010.05.002) is a self-report measure of anxiety that was designed to address unique issues associated with anxiety assessment in older adults. This study is the first to use item response theory (IRT) to examine the psychometric properties of a measure of anxiety in older adults. A large sample of older adults (n = 581; mean age = 72.32 years, SD = 7.64 years, range = 60 to 96 years; 64% women; 88% European American) completed the GAS. IRT properties were examined. The presence of differential item functioning (DIF) or measurement bias by age and sex was assessed, and a ten-item short form of the GAS (called the GAS-10) was created. All GAS items had discrimination parameters of 1.07 or greater. Items from the somatic subscale tended to have lower discrimination parameters than items on the cognitive or affective subscales. Two items were flagged for DIF, but the impact of the DIF was negligible. Women scored significantly higher than men on the GAS and its subscales. Participants in the young-old group (60 to 79 years old) scored significantly higher on the cognitive subscale than participants in the old-old group (80 years old and older). Results from the IRT analyses indicated that the GAS and GAS-10 have strong psychometric properties among older adults. We conclude by discussing implications and future research directions.

Asymptotic Standard Errors for Item Response Theory True Score Equating of Polytomous Items

Science.gov (United States)

Cher Wong, Cheow

2015-01-01

Building on previous works by Lord and Ogasawara for dichotomous items, this article proposes an approach to derive the asymptotic standard errors of item response theory true score equating involving polytomous items, for equivalent and nonequivalent groups of examinees. This analytical approach could be used in place of empirical methods like…

Qualitative Development and Content Validation of the PROMIS Pediatric Sleep Health Items.

Science.gov (United States)

Bevans, Katherine B; Meltzer, Lisa J; De La Motte, Anna; Kratchman, Amy; Viél, Dominique; Forrest, Christopher B

2018-04-25

To develop the Patient Reported Outcome Measurement Information System (PROMIS) Pediatric Sleep Health item pool and evaluate its content validity. Participants included 8 expert sleep clinician-researchers, 64 children ages 8-17 years, and 54 parents of children ages 5-17 years. We started with item concepts and expressions from the PROMIS Sleep Disturbance and Sleep Related Impairment adult measures. Additional pediatric sleep health concepts were generated by expert (n = 8), child (n = 28), and parent (n = 33) concept elicitation interviews and a systematic review of existing pediatric sleep health questionnaires. Content validity of the item pool was evaluated with item translatability review, readability analysis, and child (n = 36) and parent (n = 21) cognitive interviews. The final pediatric Sleep Health item pool includes 43 items that assess sleep disturbance (children's capacity to fall and stay asleep, sleep quality, dreams, and parasomnias) and sleep-related impairments (daytime sleepiness, low energy, difficulty waking up, and the impact of sleep and sleepiness on cognition, affect, behavior, and daily activities). Items are translatable and relevant and well understood by children ages 8-17 and parents of children ages 5-17. Rigorous qualitative procedures were used to develop and evaluate the content validity of the PROMIS Pediatric Sleep Health item pool. Once the item pool's psychometric properties are established, the scales will be useful for measuring children's subjective experiences of sleep.

MIMIC Methods for Assessing Differential Item Functioning in Polytomous Items

Science.gov (United States)

Wang, Wen-Chung; Shih, Ching-Lin

2010-01-01

Three multiple indicators-multiple causes (MIMIC) methods, namely, the standard MIMIC method (M-ST), the MIMIC method with scale purification (M-SP), and the MIMIC method with a pure anchor (M-PA), were developed to assess differential item functioning (DIF) in polytomous items. In a series of simulations, it appeared that all three methods…

Evaluation of Northwest University, Kano Post-UTME Test Items Using Item Response Theory

Science.gov (United States)

Bichi, Ado Abdu; Hafiz, Hadiza; Bello, Samira Abdullahi

2016-01-01

High-stakes testing is used for the purposes of providing results that have important consequences. Validity is the cornerstone upon which all measurement systems are built. This study applied the Item Response Theory principles to analyse Northwest University Kano Post-UTME Economics test items. The developed fifty (50) economics test items was…

Using Differential Item Functioning Procedures to Explore Sources of Item Difficulty and Group Performance Characteristics.

Science.gov (United States)

Scheuneman, Janice Dowd; Gerritz, Kalle

1990-01-01

Differential item functioning (DIF) methodology for revealing sources of item difficulty and performance characteristics of different groups was explored. A total of 150 Scholastic Aptitude Test items and 132 Graduate Record Examination general test items were analyzed. DIF was evaluated for males and females and Blacks and Whites. (SLD)

Item Response Data Analysis Using Stata Item Response Theory Package

Science.gov (United States)

Yang, Ji Seung; Zheng, Xiaying

2018-01-01

The purpose of this article is to introduce and review the capability and performance of the Stata item response theory (IRT) package that is available from Stata v.14, 2015. Using a simulated data set and a publicly available item response data set extracted from Programme of International Student Assessment, we review the IRT package from…

Item Banking with Embedded Standards

Science.gov (United States)

MacCann, Robert G.; Stanley, Gordon

2009-01-01

An item banking method that does not use Item Response Theory (IRT) is described. This method provides a comparable grading system across schools that would be suitable for low-stakes testing. It uses the Angoff standard-setting method to obtain item ratings that are stored with each item. An example of such a grading system is given, showing how…

Comparison of Alternate and Original Items on the Montreal Cognitive Assessment.

Science.gov (United States)

Lebedeva, Elena; Huang, Mei; Koski, Lisa

2016-03-01

The Montreal Cognitive Assessment (MoCA) is a screening tool for mild cognitive impairment (MCI) in elderly individuals. We hypothesized that measurement error when using the new alternate MoCA versions to monitor change over time could be related to the use of items that are not of comparable difficulty to their corresponding originals of similar content. The objective of this study was to compare the difficulty of the alternate MoCA items to the original ones. Five selected items from alternate versions of the MoCA were included with items from the original MoCA administered adaptively to geriatric outpatients (N = 78). Rasch analysis was used to estimate the difficulty level of the items. None of the five items from the alternate versions matched the difficulty level of their corresponding original items. This study demonstrates the potential benefits of a Rasch analysis-based approach for selecting items during the process of development of parallel forms. The results suggest that better match of the items from different MoCA forms by their difficulty would result in higher sensitivity to changes in cognitive function over time.

Molecular representation of molar domain (volume), evolution equations, and linear constitutive relations for volume transport.

Science.gov (United States)

Eu, Byung Chan

2008-09-07

In the traditional theories of irreversible thermodynamics and fluid mechanics, the specific volume and molar volume have been interchangeably used for pure fluids, but in this work we show that they should be distinguished from each other and given distinctive statistical mechanical representations. In this paper, we present a general formula for the statistical mechanical representation of molecular domain (volume or space) by using the Voronoi volume and its mean value that may be regarded as molar domain (volume) and also the statistical mechanical representation of volume flux. By using their statistical mechanical formulas, the evolution equations of volume transport are derived from the generalized Boltzmann equation of fluids. Approximate solutions of the evolution equations of volume transport provides kinetic theory formulas for the molecular domain, the constitutive equations for molar domain (volume) and volume flux, and the dissipation of energy associated with volume transport. Together with the constitutive equation for the mean velocity of the fluid obtained in a previous paper, the evolution equations for volume transport not only shed a fresh light on, and insight into, irreversible phenomena in fluids but also can be applied to study fluid flow problems in a manner hitherto unavailable in fluid dynamics and irreversible thermodynamics. Their roles in the generalized hydrodynamics will be considered in the sequel.

Transport volume in regions of the Czech Republic in relation to the production of waste

OpenAIRE

Pojkarová, Kateřina; Hruška, Roman

2010-01-01

The article deals with the transport volume in regions of the Czech Republic in relation to the production of waste. On the basis of waste statistics and transport statistics is researched the greatness of the relation between the transport volume and the production of waste in regions of the Czech Republic. The relation is illustrated graphically too. We have many kinds of waste which we can monitor. The most important kinds of waste are municipal waste, industrial waste, construction ...

P2-19: The Effect of item Repetition on Item-Context Association Depends on the Prior Exposure of Items

Directory of Open Access Journals (Sweden)

Hongmi Lee

2012-10-01

Full Text Available Previous studies have reported conflicting findings on whether item repetition has beneficial or detrimental effects on source memory. To reconcile such contradictions, we investigated whether the degree of pre-exposure of items can be a potential modulating factor. The experimental procedures spanned two consecutive days. On Day 1, participants were exposed to a set of unfamiliar faces. On Day 2, the same faces presented on the previous day were used again in half of the participants, whereas novel faces were used for the other half. Day 2 procedures consisted of three successive phases: item repetition, source association, and source memory test. In the item repetition phase, half of the face stimuli were repeatedly presented while participants were making male/female judgments. During the source association phase, both the repeated and the unrepeated faces appeared in one of the four locations on the screen. Finally, participants were tested on the location in which a given face was presented during the previous phase and reported the confidence of their memory. Source memory accuracy was measured as the percentage of correct non-guess trials. As results, we found a significant interaction between prior exposure and repetition. Repetition impaired source memory when the items had been pre-exposed on Day 1, while it led to greater accuracy in novel ones. These results show that pre-experimental exposure can modulate the effects of repetition on associative binding between an item and its contextual information, suggesting that pre-existing representation and novelty signal interact to form new episodic memory.

Recommended core items to assess e-cigarette use in population-based surveys.

Science.gov (United States)

Pearson, Jennifer L; Hitchman, Sara C; Brose, Leonie S; Bauld, Linda; Glasser, Allison M; Villanti, Andrea C; McNeill, Ann; Abrams, David B; Cohen, Joanna E

2018-05-01

A consistent approach using standardised items to assess e-cigarette use in both youth and adult populations will aid cross-survey and cross-national comparisons of the effect of e-cigarette (and tobacco) policies and improve our understanding of the population health impact of e-cigarette use. Focusing on adult behaviour, we propose a set of e-cigarette use items, discuss their utility and potential adaptation, and highlight e-cigarette constructs that researchers should avoid without further item development. Reliable and valid items will strengthen the emerging science and inform knowledge synthesis for policy-making. Building on informal discussions at a series of international meetings of 65 experts from 15 countries, the authors provide recommendations for assessing e-cigarette use behaviour, relative perceived harm, device type, presence of nicotine, flavours and reasons for use. We recommend items assessing eight core constructs: e-cigarette ever use, frequency of use and former daily use; relative perceived harm; device type; primary flavour preference; presence of nicotine; and primary reason for use. These items should be standardised or minimally adapted for the policy context and target population. Researchers should be prepared to update items as e-cigarette device characteristics change. A minimum set of e-cigarette items is proposed to encourage consensus around items to allow for cross-survey and cross-jurisdictional comparisons of e-cigarette use behaviour. These proposed items are a starting point. We recognise room for continued improvement, and welcome input from e-cigarette users and scientific colleagues. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Brief Sensation Seeking Scale: Latent structure of 8-item and 4-item versions in Peruvian adolescents.

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Merino-Soto, Cesar; Salas Blas, Edwin

2018-01-01

This research intended to validate two brief scales of sensations seeking with Peruvian adolescents: the eight item scale (BSSS8; Hoyle, Stephenson, Palmgreen, Lorch, y Donohew, 2002) and the four item scale (BSSS4; Stephenson, Hoyle, Slater, y Palmgreen, 2003). Questionnaires were administered to 618 voluntary participants, with an average age of 13.6 years, from different levels of high school, state and private school in a district in the south of Lima. It analyzed the internal structure of both short versions using three models: a) unidimensional (M1), b) oblique or related dimensions (M2), and c) the bifactor model (M3). Results show that both instruments have a single dimension which best represents the variability of the items; a fact that can be explained both by the complexity of the concept and by the small number of items representing each factor, which is more noticeable in the BSSS4. Reliability is within levels found by previous studies: alpha: .745 = BSSS8 and BSSS4 =. 643; omega coefficient: .747 in BSSS8 and .651 in BSSS4. These are considered suitable for the type of instruments studied. Based on the correlation between the two instruments, it was found that there are satisfactory levels of equivalence between the BSSS8 and BSSS4. However, it is recommended that the BSSS4 is mainly used for research and for the purpose of describing populations.

Local context effects during emotional item directed forgetting in younger and older adults.

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Gallant, Sara N; Dyson, Benjamin J; Yang, Lixia

2017-09-01

This paper explored the differential sensitivity young and older adults exhibit to the local context of items entering memory. We examined trial-to-trial performance during an item directed forgetting task for positive, negative, and neutral (or baseline) words each cued as either to-be-remembered (TBR) or to-be-forgotten (TBF). This allowed us to focus on how variations in emotional valence (independent of arousal) and instruction (TBR vs. TBF) of the previous item (trial n-1) impacted memory for the current item (trial n) during encoding. Different from research showing impairing effects of emotional arousal, both age groups showed a memorial boost for stimuli when preceded by items high in positive or negative valence relative to those preceded by neutral items. This advantage was particularly prominent for neutral trial n items that followed emotional items suggesting that, regardless of age, neutral memories may be strengthened by a local context that is high in valence. A trending age difference also emerged with older adults showing greater sensitivity when encoding instructions changed between trial n-1 and n. Results are discussed in light of age-related theories of cognitive and emotional processing, highlighting the need to consider the dynamic, moment-to-moment fluctuations of these systems.

Investigating the Impact of Item Parameter Drift for Item Response Theory Models with Mixture Distributions

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Yoon Soo ePark

2016-02-01

Full Text Available This study investigates the impact of item parameter drift (IPD on parameter and ability estimation when the underlying measurement model fits a mixture distribution, thereby violating the item invariance property of unidimensional item response theory (IRT models. An empirical study was conducted to demonstrate the occurrence of both IPD and an underlying mixture distribution using real-world data. Twenty-one trended anchor items from the 1999, 2003, and 2007 administrations of Trends in International Mathematics and Science Study (TIMSS were analyzed using unidimensional and mixture IRT models. TIMSS treats trended anchor items as invariant over testing administrations and uses pre-calibrated item parameters based on unidimensional IRT. However, empirical results showed evidence of two latent subgroups with IPD. Results showed changes in the distribution of examinee ability between latent classes over the three administrations. A simulation study was conducted to examine the impact of IPD on the estimation of ability and item parameters, when data have underlying mixture distributions. Simulations used data generated from a mixture IRT model and estimated using unidimensional IRT. Results showed that data reflecting IPD using mixture IRT model led to IPD in the unidimensional IRT model. Changes in the distribution of examinee ability also affected item parameters. Moreover, drift with respect to item discrimination and distribution of examinee ability affected estimates of examinee ability. These findings demonstrate the need to caution and evaluate IPD using a mixture IRT framework to understand its effect on item parameters and examinee ability.

Investigating the Impact of Item Parameter Drift for Item Response Theory Models with Mixture Distributions.

Science.gov (United States)

Park, Yoon Soo; Lee, Young-Sun; Xing, Kuan

2016-01-01

This study investigates the impact of item parameter drift (IPD) on parameter and ability estimation when the underlying measurement model fits a mixture distribution, thereby violating the item invariance property of unidimensional item response theory (IRT) models. An empirical study was conducted to demonstrate the occurrence of both IPD and an underlying mixture distribution using real-world data. Twenty-one trended anchor items from the 1999, 2003, and 2007 administrations of Trends in International Mathematics and Science Study (TIMSS) were analyzed using unidimensional and mixture IRT models. TIMSS treats trended anchor items as invariant over testing administrations and uses pre-calibrated item parameters based on unidimensional IRT. However, empirical results showed evidence of two latent subgroups with IPD. Results also showed changes in the distribution of examinee ability between latent classes over the three administrations. A simulation study was conducted to examine the impact of IPD on the estimation of ability and item parameters, when data have underlying mixture distributions. Simulations used data generated from a mixture IRT model and estimated using unidimensional IRT. Results showed that data reflecting IPD using mixture IRT model led to IPD in the unidimensional IRT model. Changes in the distribution of examinee ability also affected item parameters. Moreover, drift with respect to item discrimination and distribution of examinee ability affected estimates of examinee ability. These findings demonstrate the need to caution and evaluate IPD using a mixture IRT framework to understand its effects on item parameters and examinee ability.

Item difficulty of multiple choice tests dependant on different item response formats – An experiment in fundamental research on psychological assessment

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KLAUS D. KUBINGER

2007-12-01

Full Text Available Multiple choice response formats are problematical as an item is often scored as solved simply because the test-taker is a lucky guesser. Instead of applying pertinent IRT models which take guessing effects into account, a pragmatic approach of re-conceptualizing multiple choice response formats to reduce the chance of lucky guessing is considered. This paper compares the free response format with two different multiple choice formats. A common multiple choice format with a single correct response option and five distractors (“1 of 6” is used, as well as a multiple choice format with five response options, of which any number of the five is correct and the item is only scored as mastered if all the correct response options and none of the wrong ones are marked (“x of 5”. An experiment was designed, using pairs of items with exactly the same content but different response formats. 173 test-takers were randomly assigned to two test booklets of 150 items altogether. Rasch model analyses adduced a fitting item pool, after the deletion of 39 items. The resulting item difficulty parameters were used for the comparison of the different formats. The multiple choice format “1 of 6” differs significantly from “x of 5”, with a relative effect of 1.63, while the multiple choice format “x of 5” does not significantly differ from the free response format. Therefore, the lower degree of difficulty of items with the “1 of 6” multiple choice format is an indicator of relevant guessing effects. In contrast the “x of 5” multiple choice format can be seen as an appropriate substitute for free response format.

Racial differences in hypertension knowledge: effects of differential item functioning.

Science.gov (United States)

Ayotte, Brian J; Trivedi, Ranak; Bosworth, Hayden B

2009-01-01

Health-related knowledge is an important component in the self-management of chronic illnesses. The objective of this study was to more accurately assess racial differences in hypertension knowledge by using a latent variable modeling approach that controlled for sociodemographic factors and accounted for measurement issues in the assessment of hypertension knowledge. Cross-sectional data from 1,177 participants (45% African American; 35% female) were analyzed using a multiple indicator multiple causes (MIMIC) modeling approach. Available sociodemographic data included race, education, sex, financial status, and age. All participants completed six items on a hypertension knowledge questionnaire. Overall, the final model suggested that females, Whites, and patients with at least a high school diploma had higher latent knowledge scores than males, African Americans, and patients with less than a high school diploma, respectively. The model also detected differential item functioning (DIF) based on race for two of the items. Specifically, the error rate for African Americans was lower than would be expected given the lower level of latent knowledge on the items, on the questions related to: (a) the association between high blood pressure and kidney disease, and (b) the increased risk African Americans have for developing hypertension. Not accounting for DIF resulted in the difference between Whites and African Americans to be underestimated. These results are discussed in the context of the need for careful measurement of health-related constructs, and how measurement-related issues can result in an inaccurate estimation of racial differences in hypertension knowledge.

Solar central receiver prototype heliostat CDRL item B. d. Final technical report, Volume 2

Energy Technology Data Exchange (ETDEWEB)

Easton, C. R.

1978-08-01

This is volume II of a two volume report which presents the results of a study to define a low-cost approach to the production, installation, and operation of heliostats for central receiver solar thermal power plants. Performance and cost analyses are presented, and critical R and D areas are identified. Also, computer printed work sheets are included for heliostat investment, maintenance equipment investment, initial spares investment, and first years operations and maintenance for 2,500, 25,000, 250,000, and 1,000,000 units per year production. (WHK)

An ancient relation between units of length and volume based on a sphere.

Directory of Open Access Journals (Sweden)

Elena Zapassky

Full Text Available The modern metric system defines units of volume based on the cube. We propose that the ancient Egyptian system of measuring capacity employed a similar concept, but used the sphere instead. When considered in ancient Egyptian units, the volume of a sphere, whose circumference is one royal cubit, equals half a hekat. Using the measurements of large sets of ancient containers as a database, the article demonstrates that this formula was characteristic of Egyptian and Egyptian-related pottery vessels but not of the ceramics of Mesopotamia, which had a different system of measuring length and volume units.

ISABELLE. Volume 4. Detector R and D

International Nuclear Information System (INIS)

1981-01-01

Workshop participants were asked to assess the current status of detector R and D in terms of the specific needs for ISABELLE experiments: the demands of high particle rates, extremely selective triggers on complex and rare events, and the economics of large detector systems. The detailed results of working groups convened to consider specific areas of detector development are presented. The key points of this assessment, as regards the continuing R and D program for ISABELLE are summarized here. Twenty-six items from the volume were prepared separately for the data base, along with five items previously prepared

ISABELLE. Volume 4. Detector R and D

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

Workshop participants were asked to assess the current status of detector R and D in terms of the specific needs for ISABELLE experiments: the demands of high particle rates, extremely selective triggers on complex and rare events, and the economics of large detector systems. The detailed results of working groups convened to consider specific areas of detector development are presented. The key points of this assessment, as regards the continuing R and D program for ISABELLE are summarized here. Twenty-six items from the volume were prepared separately for the data base, along with five items previously prepared. (GHT)

Procurement Engineering Process for Commercial Grade Item Dedication

International Nuclear Information System (INIS)

Park, Jong-Hyuck; Park, Jong-Eun; Kwak, Tack-Hun; Yoo, Keun-Bae; Lee, Sang-Guk; Hong, Sung-Yull

2006-01-01

Procurement Engineering Process for commercial grade item dedication plays an increasingly important role in operation management of Korea Nuclear Power Plants. The purpose of the Procurement Engineering Process is the provision and assurance of a high quality and quantity of spare, replacement, retrofit and new parts and equipment while maximizing plant availability, minimizing downtime due to parts unavailability and providing reasonable overall program and inventory cost. In this paper, we will review the overview requirements, responsibilities and the process for demonstrating with reasonable assurance that a procured item for potential nuclear safety related services or other essential plant service is adequate with reasonable assurance for its application. This paper does not cover the details of technical evaluation, selecting critical characteristics, selecting acceptance methods, performing failure modes and effects analysis, performing source surveillance, performing quality surveys, performing special tests and inspections, and the other aspects of effective Procurement Engineering and Commercial Grade Item Dedication. The main contribution of this paper is to provide the provision of an overview of Procurement Engineering Process for commercial grade item

Attention in spina bifida myelomeningocele: Relations with brain volume and integrity

Directory of Open Access Journals (Sweden)

Paulina A. Kulesz

2015-01-01

Full Text Available This study investigated the relations of tectal volume and superior parietal cortex, as well as alterations in tectocortical white matter connectivity, with the orienting and executive control attention networks in individuals with spina bifida myelomeningocele (SBM. Probabilistic diffusion tractography and quantification of tectal and superior parietal cortical volume were performed on 74 individuals aged 8–29 with SBM and a history of hydrocephalus. Behavioral assessments measured posterior (covert orienting and anterior (conflict resolution, attentional control attention network functions. Reduced tectal volume was associated with slower covert orienting; reduced superior parietal cortical volume was associated with slower conflict resolution; and increased axial diffusivity and radial diffusivity along both frontal and parietal tectocortical pathways were associated with reduced attentional control. Results suggest that components of both the orienting and executive control attention networks are impaired in SBM. Neuroanatomical disruption to the orienting network appears more robust and a direct consequence of characteristic midbrain dysmorphology; whereas, executive control difficulties may emerge from parietal cortical anomalies and reduced frontal and parietal cortical–subcortical white matter pathways susceptible to the pathophysiological effects of congenital hydrocephalus.

Relative strengths of the calf muscles based on MRI volume measurements.

Science.gov (United States)

Jeng, Clifford L; Thawait, Gaurav K; Kwon, John Y; Machado, Antonio; Boyle, James W; Campbell, John; Carrino, John A

2012-05-01

In 1985, Silver et al. published a cadaver study which determined the relative order of strength of the muscles in the calf. Muscle strength, which is proportional to volume, was obtained by dissecting out the individual muscles, weighing them, and then multiplying by the specific gravity. No similar studies have been performed using {\\it in vivo} measurements of muscle volume. Ten normal subjects underwent 3-Tesla MRI's of both lower extremities using non-fat-saturated T2 SPACE sequences. The volume for each muscle was determined by tracing the muscle contour on sequential axial images and then interpolating the volume using imaging software. The results from this study differ from Silver's original article. The lateral head of the gastrocnemius was found to be stronger than the tibialis anterior muscle. The FHL and EDL muscles were both stronger than the peroneus longus. There was no significant difference in strength between the peroneus longus and brevis muscles. This revised order of muscle strengths in the calf based on in vivo MRI findings may assist surgeons in determining the optimal tendons to transfer in order to address muscle weakness and deformity.

The Single-Item Math Anxiety Scale: An Alternative Way of Measuring Mathematical Anxiety

Science.gov (United States)

Núñez-Peña, M. Isabel; Guilera, Georgina; Suárez-Pellicioni, Macarena

2014-01-01

This study examined whether the Single-Item Math Anxiety Scale (SIMA), based on the item suggested by Ashcraft, provided valid and reliable scores of mathematical anxiety. A large sample of university students (n = 279) was administered the SIMA and the 25-item Shortened Math Anxiety Rating Scale (sMARS) to evaluate the relation between the scores…

Use of commercial grade item dedication to reduce procurement costs

International Nuclear Information System (INIS)

Rosch, F.

1995-01-01

In the mid-1980s, the Nuclear Regulatory Industry (NRC) began inspecting utility practices of procuring and dedicating commercial grade items intended for plant safety-related applications. As a result of the industry efforts to address NRC concerns, nuclear utilities have enhanced existing programs and procedures for dedication of commercial grade items. Though these programs were originally enhanced to meet NRC concerns, utilities have discovered that the dedication of commercial grade items can also reduce overall procurement costs. This paper will discuss the enhancement of utility dedication programs and demonstrates how utilities have utilized them to reduce procurement costs

The Technical Quality of Test Items Generated Using a Systematic Approach to Item Writing.

Science.gov (United States)

Siskind, Theresa G.; Anderson, Lorin W.

The study was designed to examine the similarity of response options generated by different item writers using a systematic approach to item writing. The similarity of response options to student responses for the same item stems presented in an open-ended format was also examined. A non-systematic (subject matter expertise) approach and a…

Larger amygdala volume in first-degree relatives of patients with major depression

Directory of Open Access Journals (Sweden)

Nina Romanczuk-Seiferth

2014-01-01

Conclusions: Larger gray matter volume in healthy relatives of MDD patients point to a possible vulnerability mechanism in MDD etiology and therefore extend knowledge in the field of high-risk approaches in MDD.

The design of the run Clever randomized trial: running volume, -intensity and running-related injuries.

Science.gov (United States)

Ramskov, Daniel; Nielsen, Rasmus Oestergaard; Sørensen, Henrik; Parner, Erik; Lind, Martin; Rasmussen, Sten

2016-04-23

Injury incidence and prevalence in running populations have been investigated and documented in several studies. However, knowledge about injury etiology and prevention is needed. Training errors in running are modifiable risk factors and people engaged in recreational running need evidence-based running schedules to minimize the risk of injury. The existing literature on running volume and running intensity and the development of injuries show conflicting results. This may be related to previously applied study designs, methods used to quantify the performed running and the statistical analysis of the collected data. The aim of the Run Clever trial is to investigate if a focus on running intensity compared with a focus on running volume in a running schedule influences the overall injury risk differently. The Run Clever trial is a randomized trial with a 24-week follow-up. Healthy recreational runners between 18 and 65 years and with an average of 1-3 running sessions per week the past 6 months are included. Participants are randomized into two intervention groups: Running schedule-I and Schedule-V. Schedule-I emphasizes a progression in running intensity by increasing the weekly volume of running at a hard pace, while Schedule-V emphasizes a progression in running volume, by increasing the weekly overall volume. Data on the running performed is collected by GPS. Participants who sustain running-related injuries are diagnosed by a diagnostic team of physiotherapists using standardized diagnostic criteria. The members of the diagnostic team are blinded. The study design, procedures and informed consent were approved by the Ethics Committee Northern Denmark Region (N-20140069). The Run Clever trial will provide insight into possible differences in injury risk between running schedules emphasizing either running intensity or running volume. The risk of sustaining volume- and intensity-related injuries will be compared in the two intervention groups using a competing

Classifying running-related injuries based upon etiology, with emphasis on volume and pace

DEFF Research Database (Denmark)

Nielsen, Rasmus Oestergaard; Nohr, Ellen Aagaard; Rasmussen, Sten

2013-01-01

BACKGROUND AND PURPOSE: Many researchers acknowledge the importance of "training errors" as the main cause of running-related injuries. The purpose of this clinical commentary is to present a theoretical framework for the assumption that some running-related injuries among rear-foot strikers...... of patellofemoral pain syndrome, iliotibial band syndrome, and patellar tendinopathy, while change in running pace may be associated with the development of achilles tendinopathy, gastrocnemius injuries, and plantar fasciitis. DISCUSSIONRELATION TO CLINICAL PRACTICE: If this assertion is correct, bias may...... develop due to rapidly changing running volume, while others develop due to rapidly changing running pace. DESCRIPTION OF TOPIC WITH RELATED EVIDENCE: Evidence from clinical and experimental studies is presented to support the assertion that rapid change in running volume may lead to the development...

Developing an item bank to measure the coping strategies of people with hereditary retinal diseases.

Science.gov (United States)

Prem Senthil, Mallika; Khadka, Jyoti; De Roach, John; Lamey, Tina; McLaren, Terri; Campbell, Isabella; Fenwick, Eva K; Lamoureux, Ecosse L; Pesudovs, Konrad

2018-05-05

Our understanding of the coping strategies used by people with visual impairment to manage stress related to visual loss is limited. This study aims to develop a sophisticated coping instrument in the form of an item bank implemented via Computerised adaptive testing (CAT) for hereditary retinal diseases. Items on coping were extracted from qualitative interviews with patients which were supplemented by items from a literature review. A systematic multi-stage process of item refinement was carried out followed by expert panel discussion and cognitive interviews. The final coping item bank had 30 items. Rasch analysis was used to assess the psychometric properties. A CAT simulation was carried out to estimate an average number of items required to gain precise measurement of hereditary retinal disease-related coping. One hundred eighty-nine participants answered the coping item bank (median age = 58 years). The coping scale demonstrated good precision and targeting. The standardised residual loadings for items revealed six items grouped together. Removal of the six items reduced the precision of the main coping scale and worsened the variance explained by the measure. Therefore, the six items were retained within the main scale. Our CAT simulation indicated that, on average, less than 10 items are required to gain a precise measurement of coping. This is the first study to develop a psychometrically robust coping instrument for hereditary retinal diseases. CAT simulation indicated that on an average, only four and nine items were required to gain measurement at moderate and high precision, respectively.

Dissociative effects of orthographic distinctiveness in pure and mixed lists: an item-order account.

Science.gov (United States)

McDaniel, Mark A; Cahill, Michael; Bugg, Julie M; Meadow, Nathaniel G

2011-10-01

We apply the item-order theory of list composition effects in free recall to the orthographic distinctiveness effect. The item-order account assumes that orthographically distinct items advantage item-specific encoding in both mixed and pure lists, but at the expense of exploiting relational information present in the list. Experiment 1 replicated the typical free recall advantage of orthographically distinct items in mixed lists and the elimination of that advantage in pure lists. Supporting the item-order account, recognition performances indicated that orthographically distinct items received greater item-specific encoding than did orthographically common items in mixed and pure lists (Experiments 1 and 2). Furthermore, order memory (input-output correspondence and sequential contiguity effects) was evident in recall of pure unstructured common lists, but not in recall of unstructured distinct lists (Experiment 1). These combined patterns, although not anticipated by prevailing views, are consistent with an item-order account.

Generalizability theory and item response theory

NARCIS (Netherlands)

Glas, Cornelis A.W.; Eggen, T.J.H.M.; Veldkamp, B.P.

2012-01-01

Item response theory is usually applied to items with a selected-response format, such as multiple choice items, whereas generalizability theory is usually applied to constructed-response tasks assessed by raters. However, in many situations, raters may use rating scales consisting of items with a

Inventory of Federal energy-related environment and safety research for FY 1978. Volume 1. Executive summary

International Nuclear Information System (INIS)

1979-12-01

The FY 1978 Federal Inventory is a compilation of 3225 federally funded energy-related environmental and safety reserch projects. It consists of three volumes: an executive summary providing an overview of the data (Volume I), a catalog listing each Inventory project followed by series of indexes (Volume II), and an interactive terminal guide giving instructions for on-line data retrieval (Volume III). Volume I reviews the inventory data as a whole and also within each of three major categories: biomedical and environmental research, environmental control technology research, and operational safety research

Commingled uranium-tailings study. Volume II. Technical report

Energy Technology Data Exchange (ETDEWEB)

None

1982-06-30

Public Law 96-540, Section 213, directs the Secretary of Energy to develop a plan for a cooperative program to provide assistance in the stabilization and management of defense-related uranium mill tailings commingled with other tailings. In developing the plan, the Secretary is further directed to: (1) establish the amount and condition of tailings generated under federal contracts; (2) examine appropriate methodologies for establishing the extent of federal assistance; and (3) consult with the owners and operators of each site. This technical report summarizes US Department of Energy (DOE) and contractor activities in pursuit of items (1), (2), and (3) above. Recommendations regarding policy and a cooperative plan for federal assistance are under separate cover as Volume I.

Improving measurement of injection drug risk behavior using item response theory.

Science.gov (United States)

Janulis, Patrick

2014-03-01

Recent research highlights the multiple steps to preparing and injecting drugs and the resultant viral threats faced by drug users. This research suggests that more sensitive measurement of injection drug HIV risk behavior is required. In addition, growing evidence suggests there are gender differences in injection risk behavior. However, the potential for differential item functioning between genders has not been explored. To explore item response theory as an improved measurement modeling technique that provides empirically justified scaling of injection risk behavior and to examine for potential gender-based differential item functioning. Data is used from three studies in the National Institute on Drug Abuse's Criminal Justice Drug Abuse Treatment Studies. A two-parameter item response theory model was used to scale injection risk behavior and logistic regression was used to examine for differential item functioning. Item fit statistics suggest that item response theory can be used to scale injection risk behavior and these models can provide more sensitive estimates of risk behavior. Additionally, gender-based differential item functioning is present in the current data. Improved measurement of injection risk behavior using item response theory should be encouraged as these models provide increased congruence between construct measurement and the complexity of injection-related HIV risk. Suggestions are made to further improve injection risk behavior measurement. Furthermore, results suggest direct comparisons of composite scores between males and females may be misleading and future work should account for differential item functioning before comparing levels of injection risk behavior.

Intentional forgetting reduces color-naming interference: evidence from item-method directed forgetting.

Science.gov (United States)

Lee, Yuh-Shiow; Lee, Huang-Mou; Fawcett, Jonathan M

2013-01-01

In an item-method-directed forgetting task, Chinese words were presented individually, each followed by an instruction to remember or forget. Colored probe items were presented following each memory instruction requiring a speeded color-naming response. Half of the probe items were novel and unrelated to the preceding study item, whereas the remaining half of the probe items were a repetition of the preceding study item. Repeated probe items were either identical to the preceding study item (E1, E2), a phonetic reproduction of the preceding study item (E3), or perceptually matched to the preceding study item (E4). Color-naming interference was calculated by subtracting color-naming reaction times made in response to a string of meaningless symbols from that of the novel and repeated conditions. Across all experiments, participants recalled more to-be-remembered (TBR) than to-be-forgotten (TBF) study words. More importantly, Experiments 1 and 2 found that color-naming interference was reduced for repeated TBF words relative to repeated TBR words. Experiments 3 and 4 further found that this effect occurred at the perceptual rather than semantic level. These findings suggest that participants may bias processing resources away from the perceptual representation of to-be-forgotten information.

Dissociating the neural correlates of intra-item and inter-item working-memory binding.

Directory of Open Access Journals (Sweden)

Carinne Piekema

Full Text Available BACKGROUND: Integration of information streams into a unitary representation is an important task of our cognitive system. Within working memory, the medial temporal lobe (MTL has been conceptually linked to the maintenance of bound representations. In a previous fMRI study, we have shown that the MTL is indeed more active during working-memory maintenance of spatial associations as compared to non-spatial associations or single items. There are two explanations for this result, the mere presence of the spatial component activates the MTL, or the MTL is recruited to bind associations between neurally non-overlapping representations. METHODOLOGY/PRINCIPAL FINDINGS: The current fMRI study investigates this issue further by directly comparing intrinsic intra-item binding (object/colour, extrinsic intra-item binding (object/location, and inter-item binding (object/object. The three binding conditions resulted in differential activation of brain regions. Specifically, we show that the MTL is important for establishing extrinsic intra-item associations and inter-item associations, in line with the notion that binding of information processed in different brain regions depends on the MTL. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that different forms of working-memory binding rely on specific neural structures. In addition, these results extend previous reports indicating that the MTL is implicated in working-memory maintenance, challenging the classic distinction between short-term and long-term memory systems.

Generalizability theory and item response theory

OpenAIRE

Glas, Cornelis A.W.; Eggen, T.J.H.M.; Veldkamp, B.P.

2012-01-01

Item response theory is usually applied to items with a selected-response format, such as multiple choice items, whereas generalizability theory is usually applied to constructed-response tasks assessed by raters. However, in many situations, raters may use rating scales consisting of items with a selected-response format. This chapter presents a short overview of how item response theory and generalizability theory were integrated to model such assessments. Further, the precision of the esti...

Item Response Theory with Covariates (IRT-C): Assessing Item Recovery and Differential Item Functioning for the Three-Parameter Logistic Model

Science.gov (United States)

Tay, Louis; Huang, Qiming; Vermunt, Jeroen K.

2016-01-01

In large-scale testing, the use of multigroup approaches is limited for assessing differential item functioning (DIF) across multiple variables as DIF is examined for each variable separately. In contrast, the item response theory with covariate (IRT-C) procedure can be used to examine DIF across multiple variables (covariates) simultaneously. To…

Item response theory analysis of the Pain Self-Efficacy Questionnaire.

Science.gov (United States)

Costa, Daniel S J; Asghari, Ali; Nicholas, Michael K

2017-01-01

The Pain Self-Efficacy Questionnaire (PSEQ) is a 10-item instrument designed to assess the extent to which a person in pain believes s/he is able to accomplish various activities despite their pain. There is strong evidence for the validity and reliability of both the full-length PSEQ and a 2-item version. The purpose of this study is to further examine the properties of the PSEQ using an item response theory (IRT) approach. We used the two-parameter graded response model to examine the category probability curves, and location and discrimination parameters of the 10 PSEQ items. In item response theory, responses to a set of items are assumed to be probabilistically determined by a latent (unobserved) variable. In the graded-response model specifically, item response threshold (the value of the latent variable for which adjacent response categories are equally likely) and discrimination parameters are estimated for each item. Participants were 1511 mixed, chronic pain patients attending for initial assessment at a tertiary pain management centre. All items except item 7 ('I can cope with my pain without medication') performed well in IRT analysis, and the category probability curves suggested that participants used the 7-point response scale consistently. Items 6 ('I can still do many of the things I enjoy doing, such as hobbies or leisure activity, despite pain'), 8 ('I can still accomplish most of my goals in life, despite the pain') and 9 ('I can live a normal lifestyle, despite the pain') captured higher levels of the latent variable with greater precision. The results from this IRT analysis add to the body of evidence based on classical test theory illustrating the strong psychometric properties of the PSEQ. Despite the relatively poor performance of Item 7, its clinical utility warrants its retention in the questionnaire. The strong psychometric properties of the PSEQ support its use as an effective tool for assessing self-efficacy in people with pain

The randomly renewed general item and the randomly inspected item with exponential life distribution

International Nuclear Information System (INIS)

Schneeweiss, W.G.

1979-01-01

For a randomly renewed item the probability distributions of the time to failure and of the duration of down time and the expectations of these random variables are determined. Moreover, it is shown that the same theory applies to randomly checked items with exponential probability distribution of life such as electronic items. The case of periodic renewals is treated as an example. (orig.) [de

FORMALIZING PRODUCT COST DISTORTION: The Impact of Volume-Related Allocation Bases on Cost Information

Directory of Open Access Journals (Sweden)

Johnny Jermias

2003-09-01

Full Text Available The purpose o f this study is to formally analyze product cost distortions resulting from the process of allocating costs to products based on Activity-Based Costing (ABC and the conventional product costing systems. The model developed in this paper rigorously shows the impact of treating costs that are not volume related as if they are. The model demonstrates that the source of product cost distortion is the difference between the proportion of driver used by each product in ABC and the proportion of the base used by the same product in the conventional costing systems. The difference arises because the conventional costing systems ignore the existence of batch-related and product-related costs. The model predicts a positive association between volume and size diversity with product cost distortions. When interaction between volume and size diversity exists, the distortion is either mitigated or exacerbated. The magnitude of the distortion is jointly determined by the size of the differences and the size of the total indirect costs.

Assessment of Differential Item Functioning in Health-Related Outcomes: A Simulation and Empirical Analysis with Hierarchical Polytomous Data

Directory of Open Access Journals (Sweden)

Zahra Sharafi

2017-01-01

Full Text Available Background. The purpose of this study was to evaluate the effectiveness of two methods of detecting differential item functioning (DIF in the presence of multilevel data and polytomously scored items. The assessment of DIF with multilevel data (e.g., patients nested within hospitals, hospitals nested within districts from large-scale assessment programs has received considerable attention but very few studies evaluated the effect of hierarchical structure of data on DIF detection for polytomously scored items. Methods. The ordinal logistic regression (OLR and hierarchical ordinal logistic regression (HOLR were utilized to assess DIF in simulated and real multilevel polytomous data. Six factors (DIF magnitude, grouping variable, intraclass correlation coefficient, number of clusters, number of participants per cluster, and item discrimination parameter with a fully crossed design were considered in the simulation study. Furthermore, data of Pediatric Quality of Life Inventory™ (PedsQL™ 4.0 collected from 576 healthy school children were analyzed. Results. Overall, results indicate that both methods performed equivalently in terms of controlling Type I error and detection power rates. Conclusions. The current study showed negligible difference between OLR and HOLR in detecting DIF with polytomously scored items in a hierarchical structure. Implications and considerations while analyzing real data were also discussed.

Scoring best-worst data in unbalanced many-item designs, with applications to crowdsourcing semantic judgments.

Science.gov (United States)

Hollis, Geoff

2018-04-01

Best-worst scaling is a judgment format in which participants are presented with a set of items and have to choose the superior and inferior items in the set. Best-worst scaling generates a large quantity of information per judgment because each judgment allows for inferences about the rank value of all unjudged items. This property of best-worst scaling makes it a promising judgment format for research in psychology and natural language processing concerned with estimating the semantic properties of tens of thousands of words. A variety of different scoring algorithms have been devised in the previous literature on best-worst scaling. However, due to problems of computational efficiency, these scoring algorithms cannot be applied efficiently to cases in which thousands of items need to be scored. New algorithms are presented here for converting responses from best-worst scaling into item scores for thousands of items (many-item scoring problems). These scoring algorithms are validated through simulation and empirical experiments, and considerations related to noise, the underlying distribution of true values, and trial design are identified that can affect the relative quality of the derived item scores. The newly introduced scoring algorithms consistently outperformed scoring algorithms used in the previous literature on scoring many-item best-worst data.

Asset price and trade volume relation in artificial market impacted by value investors

Science.gov (United States)

Tangmongkollert, K.; Suwanna, S.

2016-05-01

The relationship between return and trade volume has been of great interests in a financial market. The appearance of asymmetry in the price-volume relation in the bull and bear market is still unsettled. We present a model of the value investor traders (VIs) in the double auction system, in which agents make trading decision based on the pseudo fundamental price modelled by sawtooth oscillations. We investigate the system by two different time series for the asset fundamental price: one corresponds to the fundamental price in a growing phase; and the other corresponds to that in a declining phase. The simulation results show that the trade volume is proportional to the difference between the market price and the fundamental price, and that there is asymmetry between the buying and selling phases. Furthermore, the selling phase has more significant impact of price on the trade volume than the buying phase.

A hidden variable in shear transformation zone volume versus Poisson's ratio relation in metallic glasses

Science.gov (United States)

Kim, S. Y.; Oh, H. S.; Park, E. S.

2017-10-01

Herein, we elucidate a hidden variable in a shear transformation zone (STZ) volume (Ω) versus Poisson's ratio (ν) relation and clarify the correlation between STZ characteristics and the plasticity of metallic glasses (MGs). On the basis of cooperative shear model and atomic stress theories, we carefully formulate Ω as a function of molar volume (Vm) and ν. The twofold trend in Ω and ν is attributed to a relatively large variation of Vm as compared to that of ν as well as an inverse relation between Vm and ν. Indeed, the derived equation reveals that the number of atoms in an STZ instead of Ω is a microstructural characteristic which has a close relationship with plasticity since it reflects the preference of atomistic behaviors between cooperative shearing and the generation of volume strain fluctuation under stress. The results would deepen our understanding of the correlation between microscopic behaviors (STZ activation) and macroscopic properties (plasticity) in MGs and enable a quantitative approach in associating various STZ-related macroscopic behaviors with intrinsic properties of MGs.

17 CFR 260.7a-16 - Inclusion of items, differentiation between items and answers, omission of instructions.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Inclusion of items, differentiation between items and answers, omission of instructions. 260.7a-16 Section 260.7a-16 Commodity and... INDENTURE ACT OF 1939 Formal Requirements § 260.7a-16 Inclusion of items, differentiation between items and...

Linguistic Simplification of Mathematics Items: Effects for Language Minority Students in Germany

Science.gov (United States)

Haag, Nicole; Heppt, Birgit; Roppelt, Alexander; Stanat, Petra

2015-01-01

In large-scale assessment studies, language minority students typically obtain lower test scores in mathematics than native speakers. Although this performance difference was related to the linguistic complexity of test items in some studies, other studies did not find linguistically demanding math items to be disproportionally more difficult for…

Reduced anterior cingulate and orbitofrontal volumes in child abuse-related complex PTSD

NARCIS (Netherlands)

Thomaes, K.; Dorrepaal, E.; Draijer, P.J.; de Ruiter, M.B.; van Balkom, A.J.L.M.; Smit, J.H.; Veltman, D.J.

2010-01-01

Objective: Classic posttraumatic stress disorder (PTSD) is associated with smaller hippocampus, amygdala, and anterior cingulate cortex (ACC) volumes. We investigated whether child abuse-related complex PTSD - a severe form of PTSD with affect dysregulation and high comorbidity-showed similar brain

Reduced Anterior Cingulate and Orbitofrontal Volumes in Child Abuse-Related Complex PTSD

NARCIS (Netherlands)

Thomaes, Kathleen; Dorrepaal, Ethy; Draijer, Nel; de Ruiter, Michiel B.; van Balkom, Anton J.; Smit, Johannes H.; Veltman, Dick J.

2010-01-01

Objective: Classic posttraumatic stress disorder (PTSD) is associated with smaller hippocampus, amygdala, and anterior cingulate cortex (ACC) volumes. We investigated whether child abuse-related complex PTSD a severe form of PTSD with affect dysregulation and high comorbidity-showed similar brain

The Effects of Test Length and Sample Size on Item Parameters in Item Response Theory

Science.gov (United States)

Sahin, Alper; Anil, Duygu

2017-01-01

This study investigates the effects of sample size and test length on item-parameter estimation in test development utilizing three unidimensional dichotomous models of item response theory (IRT). For this purpose, a real language test comprised of 50 items was administered to 6,288 students. Data from this test was used to obtain data sets of…

Commercial grade item (CGI) dedication of MDR relays for nuclear safety related applications

Science.gov (United States)

Das, Ranjit K.; Julka, Anil; Modi, Govind

1994-08-01

MDR relays manufactured by Potter & Brumfield (P&B) have been used in various safety related applications in commercial nuclear power plants. These include emergency safety features (ESF) actuation systems, emergency core cooling systems (ECCS) actuation, and reactor protection systems. The MDR relays manufactured prior to May 1990 showed signs of generic failure due to corrosion and outgassing of coil varnish. P&B has made design changes to correct these problems in relays manufactured after May 1990. However, P&B does not manufacture the relays under any 10CFR50 Appendix B quality assurance (QA) program. They manufacture the relays under their commercial QA program and supply these as commercial grade items. This necessitates CGI Dedication of these relays for use in nuclear-safety-related applications. This paper presents a CGI dedication program that has been used to dedicate the MDR relays manufactured after been used to dedicate the MDR relays manufactured after May 1990. The program is in compliance with current Nuclear Regulatory Commission (NRC) and Electric Power Research Institute (EPRI) guidelines and applicable industry standards; it specifies the critical characteristics of the relays, provides the tests and analysis required to verify the critical characteristics, the acceptance criteria for the test results, performs source verification to quality P&B for its control of the critical characteristics, and provides documentation. The program provides reasonable assurance that the new MDR relays will perform their intended safety functions.

Approximation Preserving Reductions among Item Pricing Problems

Science.gov (United States)

Hamane, Ryoso; Itoh, Toshiya; Tomita, Kouhei

When a store sells items to customers, the store wishes to determine the prices of the items to maximize its profit. Intuitively, if the store sells the items with low (resp. high) prices, the customers buy more (resp. less) items, which provides less profit to the store. So it would be hard for the store to decide the prices of items. Assume that the store has a set V of n items and there is a set E of m customers who wish to buy those items, and also assume that each item i ∈ V has the production cost di and each customer ej ∈ E has the valuation vj on the bundle ej ⊆ V of items. When the store sells an item i ∈ V at the price ri, the profit for the item i is pi = ri - di. The goal of the store is to decide the price of each item to maximize its total profit. We refer to this maximization problem as the item pricing problem. In most of the previous works, the item pricing problem was considered under the assumption that pi ≥ 0 for each i ∈ V, however, Balcan, et al. [In Proc. of WINE, LNCS 4858, 2007] introduced the notion of “loss-leader, ” and showed that the seller can get more total profit in the case that pi < 0 is allowed than in the case that pi < 0 is not allowed. In this paper, we derive approximation preserving reductions among several item pricing problems and show that all of them have algorithms with good approximation ratio.

Which Statistic Should Be Used to Detect Item Preknowledge When the Set of Compromised Items Is Known?

Science.gov (United States)

Sinharay, Sandip

2017-09-01

Benefiting from item preknowledge is a major type of fraudulent behavior during educational assessments. Belov suggested the posterior shift statistic for detection of item preknowledge and showed its performance to be better on average than that of seven other statistics for detection of item preknowledge for a known set of compromised items. Sinharay suggested a statistic based on the likelihood ratio test for detection of item preknowledge; the advantage of the statistic is that its null distribution is known. Results from simulated and real data and adaptive and nonadaptive tests are used to demonstrate that the Type I error rate and power of the statistic based on the likelihood ratio test are very similar to those of the posterior shift statistic. Thus, the statistic based on the likelihood ratio test appears promising in detecting item preknowledge when the set of compromised items is known.

Brain activity is related to individual differences in the number of items stored in auditory short-term memory for pitch: evidence from magnetoencephalography.

Science.gov (United States)

Grimault, Stephan; Nolden, Sophie; Lefebvre, Christine; Vachon, François; Hyde, Krista; Peretz, Isabelle; Zatorre, Robert; Robitaille, Nicolas; Jolicoeur, Pierre

2014-07-01

We used magnetoencephalography (MEG) to examine brain activity related to the maintenance of non-verbal pitch information in auditory short-term memory (ASTM). We focused on brain activity that increased with the number of items effectively held in memory by the participants during the retention interval of an auditory memory task. We used very simple acoustic materials (i.e., pure tones that varied in pitch) that minimized activation from non-ASTM related systems. MEG revealed neural activity in frontal, temporal, and parietal cortices that increased with a greater number of items effectively held in memory by the participants during the maintenance of pitch representations in ASTM. The present results reinforce the functional role of frontal and temporal cortices in the retention of pitch information in ASTM. This is the first MEG study to provide both fine spatial localization and temporal resolution on the neural mechanisms of non-verbal ASTM for pitch in relation to individual differences in the capacity of ASTM. This research contributes to a comprehensive understanding of the mechanisms mediating the representation and maintenance of basic non-verbal auditory features in the human brain. Copyright © 2014 Elsevier Inc. All rights reserved.

Longitudinal Changes in Total Brain Volume in Schizophrenia: Relation to Symptom Severity, Cognition and Antipsychotic Medication

NARCIS (Netherlands)

Veijola, J.; Guo, J.Y.; Moilanen, J.S.; Jaaskelainen, E.; Miettunen, J.; Kyllonen, M.; Haapea, M.; Huhtaniska, S.; Alaraisanen, A.; Maki, P.; Kiviniemi, V.; Nikkinen, J.; Starck, T.; Remes, J.J.; Tanskanen, P.; Tervonen, O.; Wink, A.M.; Kehagia, A.; Suckling, J.; Kobayashi, H.; Barnett, J.H.; Barnes, A.; Koponen, H.J.; Jones, P.B.; Isohanni, M.; Murray, G.K.

2014-01-01

Studies show evidence of longitudinal brain volume decreases in schizophrenia. We studied brain volume changes and their relation to symptom severity, level of function, cognition, and antipsychotic medication in participants with schizophrenia and control participants from a general population

Evolution of brain region volumes during artificial selection for relative brain size.

Science.gov (United States)

Kotrschal, Alexander; Zeng, Hong-Li; van der Bijl, Wouter; Öhman-Mägi, Caroline; Kotrschal, Kurt; Pelckmans, Kristiaan; Kolm, Niclas

2017-12-01

The vertebrate brain shows an extremely conserved layout across taxa. Still, the relative sizes of separate brain regions vary markedly between species. One interesting pattern is that larger brains seem associated with increased relative sizes only of certain brain regions, for instance telencephalon and cerebellum. Till now, the evolutionary association between separate brain regions and overall brain size is based on comparative evidence and remains experimentally untested. Here, we test the evolutionary response of brain regions to directional selection on brain size in guppies (Poecilia reticulata) selected for large and small relative brain size. In these animals, artificial selection led to a fast response in relative brain size, while body size remained unchanged. We use microcomputer tomography to investigate how the volumes of 11 main brain regions respond to selection for larger versus smaller brains. We found no differences in relative brain region volumes between large- and small-brained animals and only minor sex-specific variation. Also, selection did not change allometric scaling between brain and brain region sizes. Our results suggest that brain regions respond similarly to strong directional selection on relative brain size, which indicates that brain anatomy variation in contemporary species most likely stem from direct selection on key regions. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

An emotional functioning item bank of 24 items for computerized adaptive testing (CAT) was established

DEFF Research Database (Denmark)

Petersen, Morten Aa.; Gamper, Eva-Maria; Costantini, Anna

2016-01-01

of the widely used EORTC Quality of Life questionnaire (QLQ-C30). STUDY DESIGN AND SETTING: On the basis of literature search and evaluations by international samples of experts and cancer patients, 38 candidate items were developed. The psychometric properties of the items were evaluated in a large...... international sample of cancer patients. This included evaluations of dimensionality, item response theory (IRT) model fit, differential item functioning (DIF), and of measurement precision/statistical power. RESULTS: Responses were obtained from 1,023 cancer patients from four countries. The evaluations showed...... that 24 items could be included in a unidimensional IRT model. DIF did not seem to have any significant impact on the estimation of EF. Evaluations indicated that the CAT measure may reduce sample size requirements by up to 50% compared to the QLQ-C30 EF scale without reducing power. CONCLUSION...

Factoring handedness data: I. Item analysis.

Science.gov (United States)

Messinger, H B; Messinger, M I

1995-12-01

Recently in this journal Peters and Murphy challenged the validity of factor analyses done on bimodal handedness data, suggesting instead that right- and left-handers be studied separately. But bimodality may be avoidable if attention is paid to Oldfield's questionnaire format and instructions for the subjects. Two characteristics appear crucial: a two-column LEFT-RIGHT format for the body of the instrument and what we call Oldfield's Admonition: not to indicate strong preference for handedness item, such as write, unless "... the preference is so strong that you would never try to use the other hand unless absolutely forced to...". Attaining unimodality of an item distribution would seem to overcome the objections of Peters and Murphy. In a 1984 survey in Boston we used Oldfield's ten-item questionnaire exactly as published. This produced unimodal item distributions. With reflection of the five-point item scale and a logarithmic transformation, we achieved a degree of normalization for the items. Two surveys elsewhere based on Oldfield's 20-item list but with changes in the questionnaire format and the instructions, yielded markedly different item distributions with peaks at each extreme and sometimes in the middle as well.

Use of indicator items to monitor marine debris on a New Jersey beach from 1991 to 1996

Science.gov (United States)

Ribic, C.A.

1998-01-01

The US National Marine Debris Monitoring Program is using indicator items from beach surveys to identify whether amounts of marine debris are changing over time. Indicator items were selected through expert opinion and assumed to reflect the trend of all debris. We used monthly data from a 1991-1996 study of debris on a New Jersey beach to determine if indicator and non-indicator items showed similar trends. Total indicator debris levels did not change; this was true regardless of probable source. Non-indicator debris increased about 40% annually. Plastic non-indicator items increased regardless of whether items were whole items, cigarette filters, or pieces. Of the whole items, almost 50% were plastic lids, cups, and utensils, and about 25% were drug-related paraphernalia, tobacco-related products, plastic stirrers, pull rings, and fireworks. When indicator items are used in a monitoring programme to reflect total debris patterns, concordance of trends in indicator and non-indicator debris should be checked.

Random Item Generation Is Affected by Age

Science.gov (United States)

Multani, Namita; Rudzicz, Frank; Wong, Wing Yiu Stephanie; Namasivayam, Aravind Kumar; van Lieshout, Pascal

2016-01-01

Purpose: Random item generation (RIG) involves central executive functioning. Measuring aspects of random sequences can therefore provide a simple method to complement other tools for cognitive assessment. We examine the extent to which RIG relates to specific measures of cognitive function, and whether those measures can be estimated using RIG…

Item Modeling Concept Based on Multimedia Authoring

Directory of Open Access Journals (Sweden)

Janez Stergar

2008-09-01

Full Text Available In this paper a modern item design framework for computer based assessment based on Flash authoring environment will be introduced. Question design will be discussed as well as the multimedia authoring environment used for item modeling emphasized. Item type templates are a structured means of collecting and storing item information that can be used to improve the efficiency and security of the innovative item design process. Templates can modernize the item design, enhance and speed up the development process. Along with content creation, multimedia has vast potential for use in innovative testing. The introduced item design template is based on taxonomy of innovative items which have great potential for expanding the content areas and construct coverage of an assessment. The presented item design approach is based on GUI's – one for question design based on implemented item design templates and one for user interaction tracking/retrieval. The concept of user interfaces based on Flash technology will be discussed as well as implementation of the innovative approach of the item design forms with multimedia authoring. Also an innovative method for user interaction storage/retrieval based on PHP extending Flash capabilities in the proposed framework will be introduced.

Measuring stigma after spinal cord injury: Development and psychometric characteristics of the SCI-QOL Stigma item bank and short form.

Science.gov (United States)

Kisala, Pamela A; Tulsky, David S; Pace, Natalie; Victorson, David; Choi, Seung W; Heinemann, Allen W

2015-05-01

To develop a calibrated item bank and computer adaptive test (CAT) to assess the effects of stigma on health-related quality of life in individuals with spinal cord injury (SCI). Grounded-theory based qualitative item development methods, large-scale item calibration field testing, confirmatory factor analysis, and item response theory (IRT)-based psychometric analyses. Five SCI Model System centers and one Department of Veterans Affairs medical center in the United States. Adults with traumatic SCI. SCI-QOL Stigma Item Bank A sample of 611 individuals with traumatic SCI completed 30 items assessing SCI-related stigma. After 7 items were iteratively removed, factor analyses confirmed a unidimensional pool of items. Graded Response Model IRT analyses were used to estimate slopes and thresholds for the final 23 items. The SCI-QOL Stigma item bank is unique not only in the assessment of SCI-related stigma but also in the inclusion of individuals with SCI in all phases of its development. Use of confirmatory factor analytic and IRT methods provide flexibility and precision of measurement. The item bank may be administered as a CAT or as a 10-item fixed-length short form and can be used for research and clinical applications.

Differential item functioning of the patient-reported outcomes information system (PROMIS®) pain interference item bank by language (Spanish versus English).

Science.gov (United States)

Paz, Sylvia H; Spritzer, Karen L; Reise, Steven P; Hays, Ron D

2017-06-01

About 70% of Latinos, 5 years old or older, in the United States speak Spanish at home. Measurement equivalence of the PROMIS ® pain interference (PI) item bank by language of administration (English versus Spanish) has not been evaluated. A sample of 527 adult Spanish-speaking Latinos completed the Spanish version of the 41-item PROMIS ® pain interference item bank. We evaluate dimensionality, monotonicity and local independence of the Spanish-language items. Then we evaluate differential item functioning (DIF) using ordinal logistic regression with item response theory scores estimated from DIF-free "anchor" items. One of the 41 items in the Spanish version of the PROMIS ® PI item bank was identified as having significant uniform DIF. English- and Spanish-speaking subjects with the same level of pain interference responded differently to 1 of the 41 items in the PROMIS ® PI item bank. This item was not retained due to proprietary issues. The original English language item parameters can be used when estimating PROMIS ® PI scores.

Fatty acid intake in relation to reproductive hormones and testicular volume among young healthy men

DEFF Research Database (Denmark)

Mínguez-alarcón, Lidia; Chavarro, Jorgee; Mendiola, Jaime

2017-01-01

, and provided a blood sample. Linear regression was used to examine the association between each fatty acid type and reproductive hormone levels and testicular volumes. Monounsaturated fatty acids intake was inversely associated with serum blood levels of calculated free testosterone, total testosterone......, and inhibin B. A positive association was observed between the intake of polyunsaturated fatty acids, particularly of omega-6 polyunsaturated fatty acids, and luteinizing hormone concentrations. In addition, the intake of trans fatty acids was associated with lower total testosterone and calculated free...... testosterone concentrations (P trend = 0.01 and 0.02, respectively). The intake of omega-3 polyunsaturated fatty acids was positively related to testicular volume while the intake of omega-6 polyunsaturated fatty acids and trans fatty acids was inversely related to testicular volume. These data suggest...

A strategy for optimizing item-pool management

NARCIS (Netherlands)

Ariel, A.; van der Linden, Willem J.; Veldkamp, Bernard P.

2006-01-01

Item-pool management requires a balancing act between the input of new items into the pool and the output of tests assembled from it. A strategy for optimizing item-pool management is presented that is based on the idea of a periodic update of an optimal blueprint for the item pool to tune item

Radial Internal Material Handling System (RIMS) for Circular Habitat Volumes

Science.gov (United States)

Howe, Alan S.; Haselschwardt, Sally; Bogatko, Alex; Humphrey, Brian; Patel, Amit

2013-01-01

On planetary surfaces, pressurized human habitable volumes will require a means to carry equipment around within the volume of the habitat, regardless of the partial gravity (Earth, Moon, Mars, etc.). On the NASA Habitat Demonstration Unit (HDU), a vertical cylindrical volume, it was determined that a variety of heavy items would need to be carried back and forth from deployed locations to the General Maintenance Work Station (GMWS) when in need of repair, and other equipment may need to be carried inside for repairs, such as rover parts and other external equipment. The vertical cylindrical volume of the HDU lent itself to a circular overhead track and hoist system that allows lifting of heavy objects from anywhere in the habitat to any other point in the habitat interior. In addition, the system is able to hand-off lifted items to other material handling systems through the side hatches, such as through an airlock. The overhead system consists of two concentric circle tracks that have a movable beam between them. The beam has a hoist carriage that can move back and forth on the beam. Therefore, the entire system acts like a bridge crane curved around to meet itself in a circle. The novelty of the system is in its configuration, and how it interfaces with the volume of the HDU habitat. Similar to how a bridge crane allows coverage for an entire rectangular volume, the RIMS system covers a circular volume. The RIMS system is the first generation of what may be applied to future planetary surface vertical cylinder habitats on the Moon or on Mars.

Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

International Nuclear Information System (INIS)

Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

1987-01-01

This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation

Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

Energy Technology Data Exchange (ETDEWEB)

Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

1987-01-01

This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation.

Item response theory analyses of the Delis-Kaplan Executive Function System card sorting subtest.

Science.gov (United States)

Spencer, Mercedes; Cho, Sun-Joo; Cutting, Laurie E

2018-02-02

In the current study, we examined the dimensionality of the 16-item Card Sorting subtest of the Delis-Kaplan Executive Functioning System assessment in a sample of 264 native English-speaking children between the ages of 9 and 15 years. We also tested for measurement invariance for these items across age and gender groups using item response theory (IRT). Results of the exploratory factor analysis indicated that a two-factor model that distinguished between verbal and perceptual items provided the best fit to the data. Although the items demonstrated measurement invariance across age groups, measurement invariance was violated for gender groups, with two items demonstrating differential item functioning for males and females. Multigroup analysis using all 16 items indicated that the items were more effective for individuals whose IRT scale scores were relatively high. A single-group explanatory IRT model using 14 non-differential item functioning items showed that for perceptual ability, females scored higher than males and that scores increased with age for both males and females; for verbal ability, the observed increase in scores across age differed for males and females. The implications of these findings are discussed.

Investigation of initial contamination for disposal medical infusion items and determination of sterilization dose

International Nuclear Information System (INIS)

Hu Jinhui; Xu Ziyan; Sun Naifeng; Yan Aoshuang; Gao Wei; Wang Binglin

1993-01-01

Statistical analyses on initial contamination of 624 disposal medical infusion items are made. The normal distribution of the initial contamination, the relation of initial contamination of inner and outer walls of disposal medical infusion items and the changes of initial contamination before irradiation are shown. The sterilized dose for disposal infusion is determined as 17.2 kGy using bioburden information. The SAL (sterility assurance level) dose is 10 6 . The SIP (device sample item proportion) is 1 and the average initial contamination is 7 CFU/item

Some aspects of the relation between the volume of prostate carcinoma and its interstitial BT volume

International Nuclear Information System (INIS)

Zivanovic, A; Babic, J; Erak, M.; Dabic, K.; Donat, D.; Kuzmanovic, Z.; Savic, D.

1996-01-01

It is a fact that the volume achieved by the interstitial procedure during the brachy treatment of prostate carcinoma is several times smaller than the one we get in, so called, external beam therapy. Furthermore, interstitial brachytherapy offers the possibility to apply large dose into the small volume. However, both dose and volume are at the same time the factors that limit the therapy and the main technical offenders in case of therapy failure. We tried, through a strong individual approach, to compare the volume obtained mathematically and the volume obtained by planning (TPS). By means of clinical examinations and CT scans we conceived a prostate as half of the volume of ellipsoid under one condition only: the magnification of the prostate has to be a symmetrical one. Finally, we applied the following formula: V prostate=(1(2)) ellipsoid=2.09·a/2·e/2·b where a=(1(2)) of sagittal diameter b=prostate height (from apex to base) c=(1(2)) of transversal diameter Each volume obtained in the this way has been taken into account during the application of interstitial needles which in their own way and in accordance to a routine planning, form an active therapeutic interstitial volume. The obtained data showed differences between these two types of volumes. From the statistical point of view, mathematically obtained volume of CV was 16.6% while interstitial volume was 14.9%. T-test was 3.9. On average, mathematical volume is lower and this balance is a desirable one because it means a smaller possibility for potential positive biopsy as a result of a 'rest' tumour. If on the other hand, positive biopsy is a result of the 'rest' tumour and our interpretation has been a contradictory one, precious time with disappointing results will be lost. At the end we achieved: a) double checked control of the embraced volumes, b) stronger fulcrum for the next step: dose-fraction balance

Concreteness effects in short-term memory: a test of the item-order hypothesis.

Science.gov (United States)

Roche, Jaclynn; Tolan, G Anne; Tehan, Gerald

2011-12-01

The following experiments explore word length and concreteness effects in short-term memory within an item-order processing framework. This framework asserts order memory is better for those items that are relatively easy to process at the item level. However, words that are difficult to process benefit at the item level for increased attention/resources being applied. The prediction of the model is that differential item and order processing can be detected in episodic tasks that differ in the degree to which item or order memory are required by the task. The item-order account has been applied to the word length effect such that there is a short word advantage in serial recall but a long word advantage in item recognition. The current experiment considered the possibility that concreteness effects might be explained within the same framework. In two experiments, word length (Experiment 1) and concreteness (Experiment 2) are examined using forward serial recall, backward serial recall, and item recognition. These results for word length replicate previous studies showing the dissociation in item and order tasks. The same was not true for the concreteness effect. In all three tasks concrete words were better remembered than abstract words. The concreteness effect cannot be explained in terms of an item-order trade off. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Safety classification of items in Tianwan Nuclear Power Plant

International Nuclear Information System (INIS)

Sun Yongbin

2005-01-01

The principle of integrality, moderation and equilibrium should be considered in the safety classification of items in nuclear power plant. The basic ways for safety classification of items is to classify the safety function based on the effect of the outside enclosure damage of the items (parts) on the safety. Tianwan Nuclear Power Plant adopts Russian VVER-1000/428 type reactor, it safety classification mainly refers to Russian Guidelines and standards. The safety classification of the electric equipment refers to IEEE-308(80) standard, including 1E and Non 1E classification. The safety classification of the instrumentation and control equipment refers to GB/T 15474-1995 standard, including safety 1E, safety-related SR and NC non-safety classification. The safety classification of Tianwan Nuclear Power Plant has to be approved by NNSA and satisfy Chinese Nuclear Safety Guidelines. (authors)

Practice of radiation dose control for tech-modification items in Qinshan Nuclear Power Plant

International Nuclear Information System (INIS)

Zhang Yong; Chen Zhongyu; Xu Hongming; Fan Liguang; Jiang Jianqi; Bu Weidong

2006-01-01

In order to improve the safety and reliability of nuclear power plant operation, many tech-modifications related to system or equipment have been completed since operation in Qinshan NPP. this paper introduces radiation dose control for mainly tech-modifications items related to radiation, including radiation protection optimization measures and experience in aspects of item planning, program writing, process control, etc. (authors)

Longitudinal changes in total brain volume in schizophrenia: relation to symptom severity, cognition and antipsychotic medication.

Directory of Open Access Journals (Sweden)

Juha Veijola

Full Text Available Studies show evidence of longitudinal brain volume decreases in schizophrenia. We studied brain volume changes and their relation to symptom severity, level of function, cognition, and antipsychotic medication in participants with schizophrenia and control participants from a general population based birth cohort sample in a relatively long follow-up period of almost a decade. All members of the Northern Finland Birth Cohort 1966 with any psychotic disorder and a random sample not having psychosis were invited for a MRI brain scan, and clinical and cognitive assessment during 1999-2001 at the age of 33-35 years. A follow-up was conducted 9 years later during 2008-2010. Brain scans at both time points were obtained from 33 participants with schizophrenia and 71 control participants. Regression models were used to examine whether brain volume changes predicted clinical and cognitive changes over time, and whether antipsychotic medication predicted brain volume changes. The mean annual whole brain volume reduction was 0.69% in schizophrenia, and 0.49% in controls (p = 0.003, adjusted for gender, educational level, alcohol use and weight gain. The brain volume reduction in schizophrenia patients was found especially in the temporal lobe and periventricular area. Symptom severity, functioning level, and decline in cognition were not associated with brain volume reduction in schizophrenia. The amount of antipsychotic medication (dose years of equivalent to 100 mg daily chlorpromazine over the follow-up period predicted brain volume loss (p = 0.003 adjusted for symptom level, alcohol use and weight gain. In this population based sample, brain volume reduction continues in schizophrenia patients after the onset of illness, and antipsychotic medications may contribute to these reductions.

Two items remembered as precisely as one: how integral features can improve visual working memory.

Science.gov (United States)

Bae, Gi Yeul; Flombaum, Jonathan I

2013-10-01

In the ongoing debate about the efficacy of visual working memory for more than three items, a consensus has emerged that memory precision declines as memory load increases from one to three. Many studies have reported that memory precision seems to be worse for two items than for one. We argue that memory for two items appears less precise than that for one only because two items present observers with a correspondence challenge that does not arise when only one item is stored--the need to relate observations to their corresponding memory representations. In three experiments, we prevented correspondence errors in two-item trials by varying sample items along task-irrelevant but integral (as opposed to separable) dimensions. (Initial experiments with a classic sorting paradigm identified integral feature relationships.) In three memory experiments, our manipulation produced equally precise representations of two items and of one item.

Classifying running-related injuries based upon etiology, with emphasis on volume and pace

DEFF Research Database (Denmark)

Nielsen, R.O.; Nohr, Ellen Aagaard; Rasmussen, Sten

2013-01-01

Many researchers acknowledge the importance of "training errors" as the main cause of running-related injuries. The purpose of this clinical commentary is to present a theoretical framework for the assumption that some running-related injuries among rear-foot strikers develop due to rapidly...... changing running volume, while others develop due to rapidly changing running pace....

Investigating Separate and Concurrent Approaches for Item Parameter Drift in 3PL Item Response Theory Equating

Science.gov (United States)

Arce-Ferrer, Alvaro J.; Bulut, Okan

2017-01-01

This study examines separate and concurrent approaches to combine the detection of item parameter drift (IPD) and the estimation of scale transformation coefficients in the context of the common item nonequivalent groups design with the three-parameter item response theory equating. The study uses real and synthetic data sets to compare the two…

Instemmingsgeneigdheid en verskillende item- en responsformate in 'n gesommeerde selfbeoordelingskaal

Directory of Open Access Journals (Sweden)

Nadene Hanekom

1998-06-01

Full Text Available This study examines the degree of acquiescence present when the item and response formats of a summated rating scale are varied. It is often recommended that acquiescence response bias in rating scales may be controlled by using both positively and negatively worded items. Such items are generally worded in the Likert-type format of statements. The purpose of the study was to establish whether items in question format would result in a smaller degree of acquiescence than items worded as statements. the response format was also varied (five- and seven-point options to determine whether this would influence the reliability and degree of acquiescence in the scales. A twenty-item Locus of Control (LC questionnaire was used, but each item was complemented by its opposite, resulting in 40 items. The subjects, divided randomly into two groups, were second year students who had to complete four versions of the questionnaire, plus a shortened version of Bass's scale for measuring acquiescence. The LC version were questions or statements each combined with a five- or seven-point respons format. Partial counterbalancing was introduced by testing on two separate occasions, presenting the tests to the two groups in the opposite order. The degree of acquiescence was assessed by correlating the items with their opposite, and by correlating scores on each version with scores on the acquiescence questionnaire. No major difference were found between the various item and response format in relation to acquiescence. Opsomming Hierdie ondersoek is uitgevoer om te bepaal of die mate van instemmingsgeneigdheid deur die item- en responsformaat van 'n gesommeerde selfbeoordelingskaal beinvloed word. Daar word dikwels aanbeveel dat die gebruik van positief- sowel as negatiefbewoorde items in 'n vraelys instemmingsgeneigdheid beperk. Suike items word gewoonlik in die tradisionele Likertformaat as stellings geformuleer. Die doel van die ondersoek was om te bepaal of items

MMPI-2 Item Endorsements in Dissociative Identity Disorder vs. Simulators.

Science.gov (United States)

Brand, Bethany L; Chasson, Gregory S; Palermo, Cori A; Donato, Frank M; Rhodes, Kyle P; Voorhees, Emily F

2016-03-01

Elevated scores on some MMPI-2 (Minnesota Multiphasic Inventory-2) validity scales are common among patients with dissociative identity disorder (DID), which raises questions about the validity of their responses. Such patients show elevated scores on atypical answers (F), F-psychopathology (Fp), atypical answers in the second half of the test (FB), schizophrenia (Sc), and depression (D) scales, with Fp showing the greatest utility in distinguishing them from coached and uncoached DID simulators. In the current study, we investigated the items on the MMPI-2 F, Fp, FB, Sc, and D scales that were most and least commonly endorsed by participants with DID in our 2014 study and compared these responses with those of coached and uncoached DID simulators. The comparisons revealed that patients with DID most frequently endorsed items related to dissociation, trauma, depression, fearfulness, conflict within family, and self-destructiveness. The coached group more successfully imitated item endorsements of the DID group than did the uncoached group. However, both simulating groups, especially the uncoached group, frequently endorsed items that were uncommonly endorsed by the DID group. The uncoached group endorsed items consistent with popular media portrayals of people with DID being violent, delusional, and unlawful. These results suggest that item endorsement patterns can provide useful information to clinicians making determinations about whether an individual is presenting with DID or feigning. © 2016 American Academy of Psychiatry and the Law.

The Effects of Goal Relevance and Perceptual Features on Emotional Items and Associative Memory.

Science.gov (United States)

Mao, Wei B; An, Shu; Yang, Xiao F

2017-01-01

Showing an emotional item in a neutral background scene often leads to enhanced memory for the emotional item and impaired associative memory for background details. Meanwhile, both top-down goal relevance and bottom-up perceptual features played important roles in memory binding. We conducted two experiments and aimed to further examine the effects of goal relevance and perceptual features on emotional items and associative memory. By manipulating goal relevance (asking participants to categorize only each item image as living or non-living or to categorize each whole composite picture consisted of item image and background scene as natural scene or manufactured scene) and perceptual features (controlling visual contrast and visual familiarity) in two experiments, we found that both high goal relevance and salient perceptual features (high salience of items vs. high familiarity of items) could promote emotional item memory, but they had different effects on associative memory for emotional items and neutral backgrounds. Specifically, high goal relevance and high perceptual-salience of items could jointly impair the associative memory for emotional items and neutral backgrounds, while the effect of item familiarity on associative memory for emotional items would be modulated by goal relevance. High familiarity of items could increase associative memory for negative items and neutral backgrounds only in the low goal relevance condition. These findings suggest the effect of emotion on associative memory is not only related to attentional capture elicited by emotion, but also can be affected by goal relevance and perceptual features of stimulus.

Differential Weighting of Items to Improve University Admission Test Validity

Directory of Open Access Journals (Sweden)

Eduardo Backhoff Escudero

2001-05-01

Full Text Available This paper gives an evaluation of different ways to increase university admission test criterion-related validity, by differentially weighting test items. We compared four methods of weighting multiple-choice items of the Basic Skills and Knowledge Examination (EXHCOBA: (1 punishing incorrect responses by a constant factor, (2 weighting incorrect responses, considering the levels of error, (3 weighting correct responses, considering the item’s difficulty, based on the Classic Measurement Theory, and (4 weighting correct responses, considering the item’s difficulty, based on the Item Response Theory. Results show that none of these methods increased the instrument’s predictive validity, although they did improve its concurrent validity. It was concluded that it is appropriate to score the test by simply adding up correct responses.

Independent Orbiter Assessment (IOA): Assessment of the main propulsion subsystem FMEA/CIL, volume 2

Science.gov (United States)

Holden, K. A.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Main Propulsion System (MPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were than compared to available data from the Rockwell Downey/NASA JSC FMEA/CIL review. Volume 2 continues the presentation of IOA worksheets for MPS hardware items.

76 FR 60474 - Commercial Item Handbook

Science.gov (United States)

2011-09-29

... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System Commercial Item Handbook AGENCY.... SUMMARY: DoD has updated its Commercial Item Handbook. The purpose of the Handbook is to help acquisition personnel develop sound business strategies for procuring commercial items. DoD is seeking industry input on...

Distribution of zooplankton and its relations to food items of fish in coral areas of Karah Island, Malaysia, South China Sea

International Nuclear Information System (INIS)

Ibrahim, S.; Joni, Z.M.; Kassim, Z.; Hussin, W.M.R.W.; Zakaria, M.Z.; Hajisamae, S.

2005-01-01

The composition of food items of coral reef fish in breeding grounds of the coastal waters of Karah Island was studied. Samples of fish were caught manually by divers using conventional fishing gears. Stomachs of fish collected were removed onboard, preserved and taken to the laboratory for the analysis of the content. Crustaceous were found to be the main food item of the fish families. The selected breeding ground appeared to be the productive stations for the studied species of fish, zooplankton and the food items. The result also shows a significant relationship between the food items in fish stomachs and zooptoankton distribution. Information on the availability and distribution of food items is important for the management of fishery resources as well as for the efficient exploitation of the species. (author)

"Detecting Differential Item Functioning and Differential Step Functioning due to Differences that ""Should"" Matter"

Directory of Open Access Journals (Sweden)

Tess Miller

2010-07-01

Full Text Available This study illustrates the use of differential item functioning (DIF and differential step functioning (DSF analyses to detect differences in item difficulty that are related to experiences of examinees, such as their teachers' instructional practices, that are relevant to the knowledge, skill, or ability the test is intended to measure. This analysis is in contrast to the typical use of DIF or DSF to detect differences related to characteristics of examinees, such as gender, language, or cultural knowledge, that should be irrelevant. Using data from two forms of Ontario's Grade 9 Assessment of Mathematics, analyses were performed comparing groups of students defined by their teachers' instructional practices. All constructed-response items were tested for DIF using the Mantel Chi-Square, standardized Liu Agresti cumulative common log-odds ratio, and standardized Cox's noncentrality parameter. Items exhibiting moderate to large DIF were subsequently tested for DSF. In contrast to typical DIF or DSF analyses, which inform item development, these analyses have the potential to inform instructional practice.

SOME EMPIRICAL RELATIONS BETWEEN TRAVEL SPEED, TRAFFIC VOLUME AND TRAFFIC COMPOSITION IN URBAN ARTERIALS

Directory of Open Access Journals (Sweden)

Eleni I. VLAHOGIANNI, Ph.D.

2007-01-01

Full Text Available The effects of traffic mix (the percentage of cars, trucks, buses and so on are of particular interest in the speed-volume relationship in urban signalized arterials under various geometric and control characteristics. The paper presents some empirical observations on the relation between travel speed, traffic volume and traffic composition in urban signalized arterials. A methodology based on emerging self-organizing structures of neural networks to identify regions in the speed-volume relationship with respect to traffic composition and Bayesian networks to evaluate the effect of different types of motorized vehicles on prevailing traffic conditions is proposed. Results based on data from a large urban network indicate that the variability in traffic conditions can be described by eight regions in speed-volume relationship with respect to traffic composition. Further evaluation of the effect of motorized vehicles in each region separately indicates that the effect of traffic composition decreases with the onset of congestion. Moreover, taxis and motorcycles are the primary affecting parameter of the form of the speed-volume relationship in urban arterials.

Item Response Theory analysis of Fagerström Test for Cigarette Dependence.

Science.gov (United States)

Svicher, Andrea; Cosci, Fiammetta; Giannini, Marco; Pistelli, Francesco; Fagerström, Karl

2018-02-01

The Fagerström Test for Cigarette Dependence (FTCD) and the Heaviness of Smoking Index (HSI) are the gold standard measures to assess cigarette dependence. However, FTCD reliability and factor structure have been questioned and HSI psychometric properties are in need of further investigations. The present study examined the psychometrics properties of the FTCD and the HSI via the Item Response Theory. The study was a secondary analysis of data collected in 862 Italian daily smokers. Confirmatory factor analysis was run to evaluate the dimensionality of FTCD. A Grade Response Model was applied to FTCD and HSI to verify the fit to the data. Both item and test functioning were analyzed and item statistics, Test Information Function, and scale reliabilities were calculated. Mokken Scale Analysis was applied to estimate homogeneity and Loevinger's coefficients were calculated. The FTCD showed unidimensionality and homogeneity for most of the items and for the total score. It also showed high sensitivity and good reliability from medium to high levels of cigarette dependence, although problems related to some items (i.e., items 3 and 5) were evident. HSI had good homogeneity, adequate item functioning, and high reliability from medium to high levels of cigarette dependence. Significant Differential Item Functioning was found for items 1, 4, 5 of the FTCD and for both items of HSI. HSI seems highly recommended in clinical settings addressed to heavy smokers while FTCD would be better used in smokers with a level of cigarette dependence ranging between low and high. Copyright © 2017 Elsevier Ltd. All rights reserved.

ZNF804A risk allele is associated with relatively intact gray matter volume in patients with schizophrenia.

LENUS (Irish Health Repository)

Donohoe, Gary

2011-02-01

ZNF804A rs1344706 is the first genetic risk variant to achieve genome wide significance for psychosis. Following earlier evidence that patients carrying the ZNF804A risk allele had relatively spared memory function compared to patient non-carriers, we investigated whether ZNF804A was also associated with variation in brain volume. In a sample of 70 patients and 38 healthy participants we used voxel based morphometry to compare homozygous (AA) carriers of the ZNF804A risk allele to heterozygous and homozygous (AC\\/CC) non-carriers for both whole brain volume and specific regions implicated in earlier ZNF804A studies-the dorsolateral pre-frontal cortex, the hippocampus, and the amygdala. For patients, but not for controls, we found that homozygous \\'AA\\' risk carriers had relatively larger gray matter volumes than heterozygous\\/homozygous non-carriers (AC\\/CC), particularly for hippocampal volumes. These data are consistent with our earlier behavioral data and suggest that ZNF804A is delineating a schizophrenia subtype characterized by relatively intact brain volume. Establishing if this represents a discrete molecular pathogenesis with consequences for nosology and treatment will be an important next step in understanding ZNF084A\\'s role in illness risk.

Effect of Bcl-2 rs956572 polymorphism on age-related gray matter volume changes.

Directory of Open Access Journals (Sweden)

Mu-En Liu

Full Text Available The anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2 gene is a major regulator of neural plasticity and cellular resilience. Recently, the Bcl-2 rs956572 single nucleotide polymorphism was proposed to be a functional allelic variant that modulates cellular vulnerability to apoptosis. Our cross-sectional study investigated the genetic effect of this Bcl-2 polymorphism on age-related decreases in gray matter (GM volume across the adult lifespan. Our sample comprised 330 healthy volunteers (191 male, 139 female with a mean age of 56.2±22.0 years (range: 21-92. Magnetic resonance imaging and genotyping of the Bcl-2 rs956572 were performed for each participant. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. The association between the Bcl-2 rs956572 polymorphism and age was a predictor of regional GM volumes in the right cerebellum, bilateral lingual gyrus, right middle temporal gyrus, and right parahippocampal gyrus. We found that the volume of these five regions decreased with increasing age (all P<.001. Moreover, the downward slope was steeper among the Bcl-2 rs956572 A-allele carriers than in the G-homozygous participants. Our data provide convergent evidence for the genetic effect of the Bcl-2 functional allelic variant in brain aging. The rs956572 G-allele, which is associated with significantly higher Bcl-2 protein expression and diminished cellular sensitivity to stress-induced apoptosis, conferred a protective effect against age-related changes in brain GM volume, particularly in the cerebellum.

Item Analysis in Introductory Economics Testing.

Science.gov (United States)

Tinari, Frank D.

1979-01-01

Computerized analysis of multiple choice test items is explained. Examples of item analysis applications in the introductory economics course are discussed with respect to three objectives: to evaluate learning; to improve test items; and to help improve classroom instruction. Problems, costs and benefits of the procedures are identified. (JMD)

Early Life Stress-Related Elevations in Reaction Time Variability Are Associated with Brain Volume Reductions in HIV+ Adults

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Uraina S. Clark

2018-01-01

Full Text Available There is burgeoning evidence that, among HIV+ adults, exposure to high levels of early life stress (ELS is associated with increased cognitive impairment as well as brain volume abnormalities and elevated neuropsychiatric symptoms. Currently, we have a limited understanding of the degree to which cognitive difficulties observed in HIV+ High-ELS samples reflect underlying neural abnormalities rather than increases in neuropsychiatric symptoms. Here, we utilized a behavioral marker of cognitive function, reaction time intra-individual variability (RT-IIV, which is sensitive to both brain volume reductions and neuropsychiatric symptoms, to elucidate the unique contributions of brain volume abnormalities and neuropsychiatric symptoms to cognitive difficulties in HIV+ High-ELS adults. We assessed the relation of RT-IIV to neuropsychiatric symptom levels and total gray and white matter volumes in 44 HIV+ adults (26 with high ELS. RT-IIV was examined during a working memory task. Self-report measures assessed current neuropsychiatric symptoms (depression, stress, post-traumatic stress disorder. Magnetic resonance imaging was used to quantify total gray and white matter volumes. Compared to Low-ELS participants, High-ELS participants exhibited elevated RT-IIV, elevated neuropsychiatric symptoms, and reduced gray and white matter volumes. Across the entire sample, RT-IIV was significantly associated with gray and white matter volumes, whereas significant associations with neuropsychiatric symptoms were not observed. In the High-ELS group, despite the presence of elevated neuropsychiatric symptom levels, brain volume reductions explained more than 13% of the variance in RT-IIV, whereas neuropsychiatric symptoms explained less than 1%. Collectively, these data provide evidence that, in HIV+ High-ELS adults, ELS-related cognitive difficulties (as indexed by RT-IIV exhibit strong associations with global brain volumes, whereas ELS-related elevations in

Applying automatic item generation to create cohesive physics testlets

Science.gov (United States)

Mindyarto, B. N.; Nugroho, S. E.; Linuwih, S.

2018-03-01

Computer-based testing has created the demand for large numbers of items. This paper discusses the production of cohesive physics testlets using an automatic item generation concepts and procedures. The testlets were composed by restructuring physics problems to reveal deeper understanding of the underlying physical concepts by inserting a qualitative question and its scientific reasoning question. A template-based testlet generator was used to generate the testlet variants. Using this methodology, 1248 testlet variants were effectively generated from 25 testlet templates. Some issues related to the effective application of the generated physics testlets in practical assessments were discussed.

Software for automated tracking of open items at NRC

International Nuclear Information System (INIS)

DeWispelare, A.R.; Mackin, P.C.; Johnson, R.L.

1995-01-01

The Open Item Tracking System (OITS) was developed in response to the Nuclear Regulatory Commission (NRC) need for a reliable, easy to use automated database system, to track all open (awaiting resolution) items related to regulatory, institutional, and technical uncertainties for the Department of Energy's (DOE's) high-level waste (HLW) disposal program. The OITS system was integrated with the Regulatory Program Database (RPD) Version 1.1, resulting in the RPD/OITS Version 2.0 system. RPD/OITS is a network bases system with client server architecture and a graphical user interface. This paper outlines the system and results of its implementation

Health state evaluation of an item: A general framework and graphical representation

International Nuclear Information System (INIS)

Jiang, R.; Jardine, A.K.S.

2008-01-01

This paper presents a general theoretical framework to evaluate the health state of an item based on condition monitoring information. The item's health state is defined in terms of its relative health level and overall health level. The former is evaluated based on the relative magnitude of the composite covariate and the latter is evaluated using a fractile life of the residual life distribution at the decision instant. In addition, a method is developed to graphically represent the degradation model, failure threshold model, and the observation history of the composite covariate. As a result, the health state of the monitored item can be intuitively presented and the evaluated result can be subsequently used in a condition-based maintenance optimization decision model, which is amenable to computer modeling. A numerical example is included to illustrate the proposed approach and its appropriateness

A Comparison of the 27-Item and 12-Item Intolerance of Uncertainty Scales

Science.gov (United States)

Khawaja, Nigar G.; Yu, Lai Ngo Heidi

2010-01-01

The 27-item Intolerance of Uncertainty Scale (IUS) has become one of the most frequently used measures of Intolerance of Uncertainty. More recently, an abridged, 12-item version of the IUS has been developed. The current research used clinical (n = 50) and non-clinical (n = 56) samples to examine and compare the psychometric properties of both…

The Effects of Goal Relevance and Perceptual Features on Emotional Items and Associative Memory

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Wei B. Mao

2017-07-01

Full Text Available Showing an emotional item in a neutral background scene often leads to enhanced memory for the emotional item and impaired associative memory for background details. Meanwhile, both top–down goal relevance and bottom–up perceptual features played important roles in memory binding. We conducted two experiments and aimed to further examine the effects of goal relevance and perceptual features on emotional items and associative memory. By manipulating goal relevance (asking participants to categorize only each item image as living or non-living or to categorize each whole composite picture consisted of item image and background scene as natural scene or manufactured scene and perceptual features (controlling visual contrast and visual familiarity in two experiments, we found that both high goal relevance and salient perceptual features (high salience of items vs. high familiarity of items could promote emotional item memory, but they had different effects on associative memory for emotional items and neutral backgrounds. Specifically, high goal relevance and high perceptual-salience of items could jointly impair the associative memory for emotional items and neutral backgrounds, while the effect of item familiarity on associative memory for emotional items would be modulated by goal relevance. High familiarity of items could increase associative memory for negative items and neutral backgrounds only in the low goal relevance condition. These findings suggest the effect of emotion on associative memory is not only related to attentional capture elicited by emotion, but also can be affected by goal relevance and perceptual features of stimulus.

Encoding and retrieval processes involved in the access of source information in the absence of item memory.

Science.gov (United States)

Ball, B Hunter; DeWitt, Michael R; Knight, Justin B; Hicks, Jason L

2014-09-01

The current study sought to examine the relative contributions of encoding and retrieval processes in accessing contextual information in the absence of item memory using an extralist cuing procedure in which the retrieval cues used to query memory for contextual information were related to the target item but never actually studied. In Experiments 1 and 2, participants studied 1 category member (e.g., onion) from a variety of different categories and at test were presented with an unstudied category label (e.g., vegetable) to probe memory for item and source information. In Experiments 3 and 4, 1 member of unidirectional (e.g., credit or card) or bidirectional (e.g., salt or pepper) associates was studied, whereas the other unstudied member served as a test probe. When recall failed, source information was accessible only when items were processed deeply during encoding (Experiments 1 and 2) and when there was strong forward associative strength between the retrieval cue and target (Experiments 3 and 4). These findings suggest that a retrieval probe diagnostic of semantically related item information reinstantiates information bound in memory during encoding that results in reactivation of associated contextual information, contingent upon sufficient learning of the item itself and the association between the item and its context information.

LLWnotes - Volume 11, Number 3

International Nuclear Information System (INIS)

1996-04-01

This document is the April 1996 issue of LLWnotes. It contains articles and news items on the following topics: news items related to states and compacts, Low-Level Radioactive Waste (LLW) Forum activities, and court rulings and calendars. State and compact items featured include Texas licensing procedures, renewal of Envirocare's license, and Ward Valley. Massachusetts Board suspension of some siting tasks and Massachusetts Court rules for US DOE regarding rebates are also reported

Negative effects of item repetition on source memory.

Science.gov (United States)

Kim, Kyungmi; Yi, Do-Joon; Raye, Carol L; Johnson, Marcia K

2012-08-01

In the present study, we explored how item repetition affects source memory for new item-feature associations (picture-location or picture-color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item repetition also had a negative effect on source memory when different source dimensions were used in Phases 1 and 2 (Experiment 3) and when participants were explicitly instructed to learn source information in Phase 2 (Experiments 4 and 5). Importantly, when the order between Phases 1 and 2 was reversed, such that item repetition occurred after the encoding of critical item-source combinations, item repetition no longer affected source memory (Experiment 6). Overall, our findings did not support predictions based on item predifferentiation, within-dimension source interference, or general interference from multiple traces of an item. Rather, the findings were consistent with the idea that prior item repetition reduces attention to subsequent presentations of the item, decreasing the likelihood that critical item-source associations will be encoded.

Encyclopedia of Explosives and Related Items. Volume 7. H2 to Lysol

Science.gov (United States)

1975-01-01

29, 263 (1934) 11) Dr. (Ref 10) Konrad, Nitrocellulose 5, 124 (1934) Impact Sensitivity, it is v sens to impact even 12) Nuevos Explosivos Industriales...INTERACTION 1a) PRESSURE-DISTANCE PROFILE BEFORE INTERACTION HUGONIOT FOR MATERIAL R / MIRROR LINE- A HUGNOT FOR HUGONIOT FOR I MATERIALL (P2 u 2) STATE2...CHARACTERISTIC ’.| ’$,"(P u REFLECTION FOR MATERIAL L / 2" " 2- CHARACTERISTIC MIRROR LINE FOR MATERIALL STATE PARTICLE VELOCITY, u PARTICLE VELOCITY. u (b

Examination of the PROMIS upper extremity item bank.

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Hung, Man; Voss, Maren W; Bounsanga, Jerry; Crum, Anthony B; Tyser, Andrew R

Clinical measurement. The psychometric properties of the PROMIS v1.2 UE item bank were tested on various samples prior to its release, but have not been fully evaluated among the orthopaedic population. This study assesses the performance of the UE item bank within the UE orthopaedic patient population. The UE item bank was administered to 1197 adult patients presenting to a tertiary orthopaedic clinic specializing in hand and UE conditions and was examined using traditional statistics and Rasch analysis. The UE item bank fits a unidimensional model (outfit MNSQ range from 0.64 to 1.70) and has adequate reliabilities (person = 0.84; item = 0.82) and local independence (item residual correlations range from -0.37 to 0.34). Only one item exhibits gender differential item functioning. Most items target low levels of function. The UE item bank is a useful clinical assessment tool. Additional items covering higher functions are needed to enhance validity. Supplemental testing is recommended for patients at higher levels of function until more high function UE items are developed. 2c. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Psychometric Consequences of Subpopulation Item Parameter Drift

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Huggins-Manley, Anne Corinne

2017-01-01

This study defines subpopulation item parameter drift (SIPD) as a change in item parameters over time that is dependent on subpopulations of examinees, and hypothesizes that the presence of SIPD in anchor items is associated with bias and/or lack of invariance in three psychometric outcomes. Results show that SIPD in anchor items is associated…

Life sciences payload definition and integration study. Volume 3: Appendices

Science.gov (United States)

1972-01-01

Detail design information concerning payloads for biomedical research projects conducted during space missions is presented. Subjects discussed are: (1) equipment modules and equipment item lists, (2) weight and volume breakdown by payload and equipment units, (3) longitudinal floor arrangement configuration, and (4) nonbaseline second generation layouts.

Proceedings of the 1984 workshop on high-energy excitations in condensed matter. Volume II

International Nuclear Information System (INIS)

Silver, R.N.

1984-12-01

This volume covers electronic excitations, momentum distributions, high energy photons, and a wrap-up session. Abstracts of individual items from the conference were prepared separately for the data base

48 CFR 852.214-72 - Alternate item(s).

Science.gov (United States)

2010-10-01

... AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses 852.214-72... 2008) Bids on []* will be given equal consideration along with bids on []** and any such bids received... [].** * Contracting officer will insert an alternate item that is considered acceptable. ** Contracting officer will...

A New Functional Health Literacy Scale for Japanese Young Adults Based on Item Response Theory.

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Tsubakita, Takashi; Kawazoe, Nobuo; Kasano, Eri

2017-03-01

Health literacy predicts health outcomes. Despite concerns surrounding the health of Japanese young adults, to date there has been no objective assessment of health literacy in this population. This study aimed to develop a Functional Health Literacy Scale for Young Adults (funHLS-YA) based on item response theory. Each item in the scale requires participants to choose the most relevant term from 3 choices in relation to a target item, thus assessing objective rather than perceived health literacy. The 20-item scale was administered to 1816 university students and 1751 responded. Cronbach's α coefficient was .73. Difficulty and discrimination parameters of each item were estimated, resulting in the exclusion of 1 item. Some items showed different difficulty parameters for male and female participants, reflecting that some aspects of health literacy may differ by gender. The current 19-item version of funHLS-YA can reliably assess the objective health literacy of Japanese young adults.

Volume and Tissue Composition Changes Measured with Dual-Energy X-Ray Absorptiometry in Melanoma-Related Limb Lymphedema

DEFF Research Database (Denmark)

Gjorup, Caroline A; Hendel, Helle W; Zerahn, Bo

2017-01-01

Abstracts Background: The aim of this cross-sectional study was to investigate the volume, fat mass, and lean mass in both upper and lower limbs measured with dual-energy X-ray absorptiometry (DXA) in melanoma patients with melanoma-related limb lymphedema. METHODS AND RESULTS: Four hundred thirty...... lymphedema was diagnosed on the basis of history and characteristic physical findings on the clinical examination. The inter-limb differences in volume, fat mass, and lean mass measured with DXA were categorized as none/mild, moderate, or severe according to reference values (taking handedness into account......, and the majority of lymphedemas were categorized as mild. The increase in the volume of limbs with lymphedema was primarily due to an increase in fat mass. CONCLUSION: There is a high prevalence of melanoma-related limb lymphedema. The increase in volume in the limb with lymphedema is primarily due to an increase...

Independent Orbiter Assessment (IOA): Assessment of the main propulsion subsystem FMEA/CIL, volume 3

Science.gov (United States)

Holden, K. A.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Main Propulsion System (MPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to available data from the Rockwell Downey/NASA JSC FMEA/CIL review. Volume 3 continues the presentation of IOA worksheets and includes the potential critical items list.

Macrostructural Treatment of Multi-word Lexical Items

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Alenka Vrbinc

2011-05-01

Full Text Available The paper discusses the macrostructural treatment of multi-word lexical items in mono- and bilingual dictionaries. First, the classification of multi-word lexical items is presented, and special attention is paid to the discussion of compounds – a specific group of multi-word lexical items that is most commonly afforded headword status but whose inclusion in the headword list may also depend on spelling. Then the inclusion of multi-word lexical items in monolingual dictionaries is dealt with in greater detail, while the results of a short survey on the inclusion of five randomly chosen multi-word lexical items in seven English monolingual dictionaries are presented. The proposals as to how to treat these five multi-word lexical items in bilingual dictionaries are presented in the section about the inclusion of multi-word lexical items in bilingual dictionaries. The conclusion is that it is most important to take the users’ needs into consideration and to make any dictionary as user friendly as possible.

Losing Items in the Psychogeriatric Nursing Home

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J. van Hoof PhD

2016-09-01

Full Text Available Introduction: Losing items is a time-consuming occurrence in nursing homes that is ill described. An explorative study was conducted to investigate which items got lost by nursing home residents, and how this affects the residents and family caregivers. Method: Semi-structured interviews and card sorting tasks were conducted with 12 residents with early-stage dementia and 12 family caregivers. Thematic analysis was applied to the outcomes of the sessions. Results: The participants stated that numerous personal items and assistive devices get lost in the nursing home environment, which had various emotional, practical, and financial implications. Significant amounts of time are spent on trying to find items, varying from 1 hr up to a couple of weeks. Numerous potential solutions were identified by the interviewees. Discussion: Losing items often goes together with limitations to the participation of residents. Many family caregivers are reluctant to replace lost items, as these items may get lost again.

Use of other industry standards to facilitate the procurement and dedication of commercial-grade items

International Nuclear Information System (INIS)

Beard, R.L.; Rosch, F.C.; Sanwarwalla, M.H.; Tjernlund, R.M.

1994-01-01

Nuclear utilities are embarking on innovative approaches for reducing costs in all aspects of engineering, operation, maintenance, and procurement to produce power cheaply and efficiently and remain competitive with other power producers. In the area of procurement, utilities are increasingly obtaining commercial-grade items for use in safety-related applications. This trend is occurring because of lack of suppliers capable or willing to meet 10 CFR 21 and 10 CFR 50 App. B requirements and because of the absence of original equipment suppliers or the spiraling cost associated with procuring items' basic components safety-related from original suppliers. Utilities have been looking at ways to reduce procurement costs. One promising means to reduce costs is to utilize information provided in other nonnuclear industry standards regarding the specification, control, manufacture, and acceptance of the critical characteristics required of the item to perform its design function. A task force was instituted under the sponsorship of the Electric Power Research Institute to investigate the feasibility of using items manufactured to other industry standards in nuclear safety-related applications. This investigation looked at a broad spectrum of available industry standards pertaining to the design, function, manufacture, and testing of items and determined that some standards are more useful than others. This paper discusses the results of this investigation and how credit from the controls exercised for items manufactured to certain existing industry standards can be taken to minimize dedication costs

‘Forget me (not?’ – Remembering forget-items versus un-cued items in directed forgetting

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Bastian eZwissler

2015-11-01

Full Text Available Humans need to be able to selectively control their memories. Here, we investigate the underlying processes in item-method directed forgetting and compare the classic active memory cues in this paradigm with a passive instruction. Typically, individual items are presented and each is followed by either a forget- or remember-instruction. On a surprise test of all items, memory is then worse for to-be-forgotten items (TBF compared to to-be-remembered items (TBR. This is thought to result from selective rehearsal of TBR, or from active inhibition of TBF, or from both. However, evidence suggests that if a forget instruction initiates active processing, paradoxical effects may also arise. To investigate the underlying mechanisms, four experiments were conducted where un-cued items (UI were introduced and recognition performance was compared between TBR, TBF and UI stimuli. Accuracy was encouraged via a performance-dependent monetary bonus. Across all experiments, including perceptually fully matched variants, memory accuracy for TBF was reduced compared to TBR, but better than for UI. Moreover, participants used a more conservative response criterion when responding to TBF stimuli. Thus, ironically, the F cue results in active processing, but this does not have inhibitory effects that would impair recognition memory beyond a un-cued baseline condition. This casts doubts on inhibitory accounts of item-method directed forgetting and is also difficult to reconcile with pure selective rehearsal of TBR. While the F-cue does induce active processing, this does not result in particularly successful forgetting. The pattern seems most consistent with the notion of ironic processing.

A comparative study on component volumes from outer to inner dental enamel in relation to enamel tufts.

Science.gov (United States)

Setally Azevedo Macena, Marcus; de Alencar e Silva Leite, Maria Luísa; de Lima Gouveia, Cíntia; de Lima, Tamires Alcoforado Sena; Athayde, Priscilla Alves Aguiar; de Sousa, Frederico Barbosa

2014-06-01

Dental enamel presents marked mechanical properties gradients from outer to inner enamel, a region lacking component volumes profiles. Tufts, structures of inner enamel, have been shown to play a role in enamel resilience. We aimed at comparing component volumes from inner to outer enamel in relation to enamel tufts. Transversal ground sections from the cervical half of unerupted human third molars (n=10) were prepared and histological points were selected along transversal lines (extending from innermost to outer enamel) traced across tufts and adjacent control areas without tufts. Component volumes were measured at each histological point. Component volumes ranges were: 70.6-98.5% (mineral), 0.02-20.78% (organic), 3.8-9.8% (total water), 3-9% (firmly bound water), and 0.02-3.3% (loosely bound water). Inner enamel presented the lowest mineral volumes and the highest non-mineral volumes. Mineral, water and organic contents differed as a function of the distance from innermost enamel but not between the tuft and control lines. Tufts presented opaqueness in polarizing microscopy (feature of fracture lines). Organic volume gradient correlated with a relatively flat profile of loosely bound water. Inner, but not outer enamel, rehydrated after air-dried enamel was heated to 50°C and re-exposed to room conditions, as predicted by the organic/water gradient profiles. Component volumes vary markedly from outer to inner enamel, but not between areas with or without tufts (that behave like fracture lines under polarizing microscopy). Copyright © 2014 Elsevier Ltd. All rights reserved.

BDNF val(66)met affects hippocampal volume and emotion-related hippocampal memory activity

NARCIS (Netherlands)

Molendijk, M. L.; van Tol, M-J; Penninx, B. W. J. H.; van der Wee, N. J. A.; Aleman, A.; Veltman, D. J.; Spinhoven, P.; Elzinga, B. M.

2012-01-01

The val(66)met polymorphism on the BDNF gene has been reported to explain individual differences in hippocampal volume and memory-related activity. These findings, however, have not been replicated consistently and no studies to date controlled for the potentially confounding impact of early life

Item selection via Bayesian IRT models.

Science.gov (United States)

Arima, Serena

2015-02-10

With reference to a questionnaire that aimed to assess the quality of life for dysarthric speakers, we investigate the usefulness of a model-based procedure for reducing the number of items. We propose a mixed cumulative logit model, which is known in the psychometrics literature as the graded response model: responses to different items are modelled as a function of individual latent traits and as a function of item characteristics, such as their difficulty and their discrimination power. We jointly model the discrimination and the difficulty parameters by using a k-component mixture of normal distributions. Mixture components correspond to disjoint groups of items. Items that belong to the same groups can be considered equivalent in terms of both difficulty and discrimination power. According to decision criteria, we select a subset of items such that the reduced questionnaire is able to provide the same information that the complete questionnaire provides. The model is estimated by using a Bayesian approach, and the choice of the number of mixture components is justified according to information criteria. We illustrate the proposed approach on the basis of data that are collected for 104 dysarthric patients by local health authorities in Lecce and in Milan. Copyright © 2014 John Wiley & Sons, Ltd.

Development of the Quantitative Reasoning Items on the National Survey of Student Engagement

Directory of Open Access Journals (Sweden)

Amber D. Dumford

2015-01-01

Full Text Available As society’s needs for quantitative skills become more prevalent, college graduates require quantitative skills regardless of their career choices. Therefore, it is important that institutions assess students’ engagement in quantitative activities during college. This study chronicles the process taken by the National Survey of Student Engagement (NSSE to develop items that measure students’ participation in quantitative reasoning (QR activities. On the whole, findings across the quantitative and qualitative analyses suggest good overall properties for the developed QR items. The items show great promise to explore and evaluate the frequency with which college students participate in QR-related activities. Each year, hundreds of institutions across the United States and Canada participate in NSSE, and, with the addition of these new items on the core survey, every participating institution will have information on this topic. Our hope is that these items will spur conversations on campuses about students’ use of quantitative reasoning activities.

Thermodynamics of volume-collapse transitions in cerium and related compounds

International Nuclear Information System (INIS)

Bustingorry, S.; Jagla, E.A.; Lorenzana, J.

2005-01-01

We present a non-linear elastic model of a coherent transition with discontinuous volume change in an isotropic solid. The model reproduces the anomalous thermodynamics typical of coherent equilibrium including intrinsic hysteresis (for a pressure driven experiment) and a negative bulk modulus. The novelty of the model is that the statistical mechanics solution can be easily worked out. We find that coherency leads to an infinite-range density-density interaction, which drives classical critical behavior. The pressure width of the hysteresis loop shrinks with increasing temperature, ending at a critical point at a temperature related to the shear modulus. The bulk modulus softens with a 1/2 exponent at the transition even far from the critical point. Many well known features of the phase diagram of Ce and related systems are explained by the model

Item response theory analysis of the life orientation test-revised: age and gender differential item functioning analyses.

Science.gov (United States)

Steca, Patrizia; Monzani, Dario; Greco, Andrea; Chiesi, Francesca; Primi, Caterina

2015-06-01

This study is aimed at testing the measurement properties of the Life Orientation Test-Revised (LOT-R) for the assessment of dispositional optimism by employing item response theory (IRT) analyses. The LOT-R was administered to a large sample of 2,862 Italian adults. First, confirmatory factor analyses demonstrated the theoretical conceptualization of the construct measured by the LOT-R as a single bipolar dimension. Subsequently, IRT analyses for polytomous, ordered response category data were applied to investigate the items' properties. The equivalence of the items across gender and age was assessed by analyzing differential item functioning. Discrimination and severity parameters indicated that all items were able to distinguish people with different levels of optimism and adequately covered the spectrum of the latent trait. Additionally, the LOT-R appears to be gender invariant and, with minor exceptions, age invariant. Results provided evidence that the LOT-R is a reliable and valid measure of dispositional optimism. © The Author(s) 2014.

Development of the Oxford Participation and Activities Questionnaire: constructing an item pool

Directory of Open Access Journals (Sweden)

Kelly L

2015-05-01

Full Text Available Laura Kelly, Crispin Jenkinson, Sarah Dummett, Jill Dawson, Ray Fitzpatrick, David Morley Health Services Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK Purpose: The Oxford Participation and Activities Questionnaire is a patient-reported outcome measure in development that is grounded on the World Health Organization International Classification of Functioning, Disability, and Health (ICF. The study reported here aimed to inform and generate an item pool for the new measure, which is specifically designed for the assessment of participation and activity in patients experiencing a range of health conditions. Methods: Items were informed through in-depth interviews conducted with 37 participants spanning a range of conditions. Interviews aimed to identify how their condition impacted their ability to participate in meaningful activities. Conditions included arthritis, cancer, chronic back pain, diabetes, motor neuron disease, multiple sclerosis, Parkinson's disease, and spinal cord injury. Transcripts were analyzed using the framework method. Statements relating to ICF themes were recast as questionnaire items and shown for review to an expert panel. Cognitive debrief interviews (n=13 were used to assess items for face and content validity. Results: ICF themes relevant to activities and participation in everyday life were explored, and a total of 222 items formed the initial item pool. This item pool was refined by the research team and 28 generic items were mapped onto all nine chapters of the ICF construct, detailing activity and participation. Cognitive interviewing confirmed the questionnaire instructions, items, and response options were acceptable to participants. Conclusion: Using a clear conceptual basis to inform item generation, 28 items have been identified as suitable to undergo further psychometric testing. A large-scale postal survey will follow in order to refine the instrument further and

The quadratic relationship between difficulty of intelligence test items and their correlations with working memory

Directory of Open Access Journals (Sweden)

Tomasz eSmoleń

2015-08-01

Full Text Available Fluid intelligence (Gf is a crucial cognitive ability that involves abstract reasoning in order to solve novel problems. Recent research demonstrated that Gf strongly depends on the individual effectiveness of working memory (WM. We investigated a popular claim that if the storage capacity underlay the WM-Gf correlation, then such a correlation should increase with an increasing number of items or rules (load in a Gf test. As often no such link is observed, on that basis the storage-capacity account is rejected, and alternative accounts of Gf (e.g., related to executive control or processing speed are proposed. Using both analytical inference and numerical simulations, we demonstrated that the load-dependent change in correlation is primarily a function of the amount of floor/ceiling effect for particular items. Thus, the item-wise WM correlation of a Gf test depends on its overall difficulty, and the difficulty distribution across its items. When the early test items yield huge ceiling, but the late items do not approach floor, that correlation will increase throughout the test. If the early items locate themselves between ceiling and floor, but the late items approach floor, the respective correlation will decrease. For a hallmark Gf test, the Raven test, whose items span from ceiling to floor, the quadratic relationship is expected, and it was shown empirically using a large sample and two types of WMC tasks. In consequence, no changes in correlation due to varying WM/Gf load, or lack of them, can yield an argument for or against any theory of WM/Gf. Moreover, as the mathematical properties of the correlation formula make it relatively immune to ceiling/floor effects for overall moderate correlations, only minor changes (if any in the WM-Gf correlation should be expected for many psychological tests.

The quadratic relationship between difficulty of intelligence test items and their correlations with working memory.

Science.gov (United States)

Smolen, Tomasz; Chuderski, Adam

2015-01-01

Fluid intelligence (Gf) is a crucial cognitive ability that involves abstract reasoning in order to solve novel problems. Recent research demonstrated that Gf strongly depends on the individual effectiveness of working memory (WM). We investigated a popular claim that if the storage capacity underlay the WM-Gf correlation, then such a correlation should increase with an increasing number of items or rules (load) in a Gf-test. As often no such link is observed, on that basis the storage-capacity account is rejected, and alternative accounts of Gf (e.g., related to executive control or processing speed) are proposed. Using both analytical inference and numerical simulations, we demonstrated that the load-dependent change in correlation is primarily a function of the amount of floor/ceiling effect for particular items. Thus, the item-wise WM correlation of a Gf-test depends on its overall difficulty, and the difficulty distribution across its items. When the early test items yield huge ceiling, but the late items do not approach floor, that correlation will increase throughout the test. If the early items locate themselves between ceiling and floor, but the late items approach floor, the respective correlation will decrease. For a hallmark Gf-test, the Raven-test, whose items span from ceiling to floor, the quadratic relationship is expected, and it was shown empirically using a large sample and two types of WMC tasks. In consequence, no changes in correlation due to varying WM/Gf load, or lack of them, can yield an argument for or against any theory of WM/Gf. Moreover, as the mathematical properties of the correlation formula make it relatively immune to ceiling/floor effects for overall moderate correlations, only minor changes (if any) in the WM-Gf correlation should be expected for many psychological tests.

Software Note: Using BILOG for Fixed-Anchor Item Calibration

Science.gov (United States)

DeMars, Christine E.; Jurich, Daniel P.

2012-01-01

The nonequivalent groups anchor test (NEAT) design is often used to scale item parameters from two different test forms. A subset of items, called the anchor items or common items, are administered as part of both test forms. These items are used to adjust the item calibrations for any differences in the ability distributions of the groups taking…

Encoding and Retrieval Processes Involved in the Access of Source Information in the Absence of Item Memory

Science.gov (United States)

Ball, B. Hunter; DeWitt, Michael R.; Knight, Justin B.; Hicks, Jason L.

2014-01-01

The current study sought to examine the relative contributions of encoding and retrieval processes in accessing contextual information in the absence of item memory using an extralist cuing procedure in which the retrieval cues used to query memory for contextual information were "related" to the target item but never actually studied.…

Inventions on presenting textual items in Graphical User Interface

OpenAIRE

Mishra, Umakant

2014-01-01

Although a GUI largely replaces textual descriptions by graphical icons, the textual items are not completely removed. The textual items are inevitably used in window titles, message boxes, help items, menu items and popup items. Textual items are necessary for communicating messages that are beyond the limitation of graphical messages. However, it is necessary to harness the textual items on the graphical interface in such a way that they complement each other to produce the best effect. One...

Feed mechanism and method for feeding minute items

Science.gov (United States)

Stringer, Timothy Kent [Bucyrus, KS; Yerganian, Simon Scott [Lee's Summit, MO

2009-10-20

A feeding mechanism and method for feeding minute items, such as capacitors, resistors, or solder preforms. The mechanism is adapted to receive a plurality of the randomly-positioned and randomly-oriented extremely small or minute items, and to isolate, orient, and position one or more of the items in a specific repeatable pickup location wherefrom they may be removed for use by, for example, a computer-controlled automated assembly machine. The mechanism comprises a sliding shelf adapted to receive and support the items; a wiper arm adapted to achieve a single even layer of the items; and a pushing arm adapted to push the items into the pickup location. The mechanism can be adapted for providing the items with a more exact orientation, and can also be adapted for use in a liquid environment.

Evaluation of the Relative Validity and Test-Retest Reliability of a 15-Item Beverage Intake Questionnaire in Children and Adolescents.

Science.gov (United States)

Hill, Catelyn E; MacDougall, Carly R; Riebl, Shaun K; Savla, Jyoti; Hedrick, Valisa E; Davy, Brenda M

2017-11-01

Added sugar intake, in the form of sugar-sweetened beverages (SSBs), may contribute to weight gain and obesity development in children and adolescents. A valid and reliable brief beverage intake assessment tool for children and adolescents could facilitate research in this area. The purpose of this investigation was to evaluate the relative validity and test-retest reliability of a 15-item beverage intake questionnaire (BEVQ) for assessing usual beverage intake in children and adolescents. This cross-sectional investigation included four study visits within a 2- to 3-week time period. Participants (333 enrolled; 98% completion rate) were children aged 6 to 11 years and adolescents aged 12 to18 years recruited from the New River Valley, VA, region from January 2014 to September 2015. Study visits included assessment of height/weight, health history, and four 24-hour dietary recalls (24HRs). The BEVQ was completed at two visits (BEVQ 1, BEVQ 2). To evaluate relative validity, BEVQ 1 was compared with habitual beverage intake determined by the averaged 24HR. To evaluate test-retest reliability, BEVQ 1 was compared with BEVQ 2. Analyses included descriptive statistics, independent sample t tests, χ 2 tests, one-way analysis of variance, paired sample t tests, and correlational analyses. In the full sample, self-reported water and total SSB intake were not different between BEVQ 1 and 24HR (mean differences 0±1 fl oz and 0±1 fl oz, respectively; both P values >0.05). Reported intake across all beverage categories was significantly correlated between BEVQ 1 and BEVQ 2 (Pbeverages was not different (all P values >0.05) between BEVQ 1 and 24HR (mean differences: whole milk=3±4 kcal, reduced-fat milk=9±5 kcal, and fat-free milk=7±6 kcal, which is 7±15 total beverage kilocalories). In adolescents (n=200), water and SSB kilocalories were not different (both P values >0.05) between BEVQ 1 and 24HR (mean differences: -1±1 fl oz and 12±9 kcal, respectively). A 15

Does the oscillation of the water volume of the reservoir influence in the same way in fish diet?

Directory of Open Access Journals (Sweden)

Jean Carlos Dantas de Oliveira

2018-04-01

Full Text Available Abstract Aim: To evaluate the fish feeding and to establish the preferential and secondary items of their diets, to determine the trophic guilds and the possible trophic structure variations in function of the water volume in Umari reservoir, Rio Grande do Norte, Brazilian semiarid. Methods The fish were captured quarterly between February and November of 2013, with gill nets with different meshes, being the apparatuses exposed at 5:00 p.m., with removal at 5:00 a.m. The food items were identified using stereoscopic and optical microscopes and evaluated through the Feeding Index (IAi, being the results of this procedure used in food similarity analysis. The volume of the items was orderly in NMDS and the time differences were tested in PERMANOVA. Results A total of 740 individuals belonging to 14 species were sampled, being analyzed a total of 258 stomachs and 8 intestines of 11 species. From the IAi values used in the trophic similarity analysis, the species were classified into five trophic guilds: detritivorous, insectivorous, malacophagous, carcinophagous and piscivorous. Conclusion The oscillation in the water volume of the reservoir did not influence the diet of the guild detritivorous, which shows that the variations in the volume of water of the reservoir do not influence in the same way the diet of the local ichthyofauna.

Reading ability and print exposure: item response theory analysis of the author recognition test.

Science.gov (United States)

Moore, Mariah; Gordon, Peter C

2015-12-01

In the author recognition test (ART), participants are presented with a series of names and foils and are asked to indicate which ones they recognize as authors. The test is a strong predictor of reading skill, and this predictive ability is generally explained as occurring because author knowledge is likely acquired through reading or other forms of print exposure. In this large-scale study (1,012 college student participants), we used item response theory (IRT) to analyze item (author) characteristics in order to facilitate identification of the determinants of item difficulty, provide a basis for further test development, and optimize scoring of the ART. Factor analysis suggested a potential two-factor structure of the ART, differentiating between literary and popular authors. Effective and ineffective author names were identified so as to facilitate future revisions of the ART. Analyses showed that the ART is a highly significant predictor of the time spent encoding words, as measured using eyetracking during reading. The relationship between the ART and time spent reading provided a basis for implementing a higher penalty for selecting foils, rather than the standard method of ART scoring (names selected minus foils selected). The findings provide novel support for the view that the ART is a valid indicator of reading volume. Furthermore, they show that frequency data can be used to select items of appropriate difficulty, and that frequency data from corpora based on particular time periods and types of texts may allow adaptations of the test for different populations.

78 FR 31431 - Export Administration Regulations (EAR): Control of Spacecraft Systems and Related Items the...

Science.gov (United States)

2013-05-24

... inappropriate to include these types of items in the ``600 series,'' which is, by definition, comprised of... also add a new definition for the ``500 series'' to Sec. 772.1. The new ``500 series'' would not... space tourism, research or scientific endeavors, or transportation from one point to another for...

Applying Hierarchical Model Calibration to Automatically Generated Items.

Science.gov (United States)

Williamson, David M.; Johnson, Matthew S.; Sinharay, Sandip; Bejar, Isaac I.

This study explored the application of hierarchical model calibration as a means of reducing, if not eliminating, the need for pretesting of automatically generated items from a common item model prior to operational use. Ultimately the successful development of automatic item generation (AIG) systems capable of producing items with highly similar…

41 CFR 101-27.404 - Review of items.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Review of items. 101-27.404 Section 101-27.404 Public Contracts and Property Management Federal Property Management...-Elimination of Items From Inventory § 101-27.404 Review of items. Except for standby or reserve stocks, items...

Towards an authoring system for item construction

NARCIS (Netherlands)

Rikers, Jos H.A.N.

1988-01-01

The process of writing test items is analyzed, and a blueprint is presented for an authoring system for test item writing to reduce invalidity and to structure the process of item writing. The developmental methodology is introduced, and the first steps in the process are reported. A historical

Modeling Local Item Dependence in Cloze and Reading Comprehension Test Items Using Testlet Response Theory

Science.gov (United States)

Baghaei, Purya; Ravand, Hamdollah

2016-01-01

In this study the magnitudes of local dependence generated by cloze test items and reading comprehension items were compared and their impact on parameter estimates and test precision was investigated. An advanced English as a foreign language reading comprehension test containing three reading passages and a cloze test was analyzed with a…

Cultural Interchangeability? Culture-Specific Items in Translation

Directory of Open Access Journals (Sweden)

Ajtony Zsuzsanna

2016-12-01

Full Text Available This paper summarizes the results of the translation work carried out within an international project aiming to develop the language skills of staff working in hotel and catering services. As the topics touched upon in the English source texts are related to several European cultures, these cultural differences bring about several challenges related to the translation of realia, or culture-specific items (CSIs. In the first part of the paper, a series of translation strategies for rendering source-language CSIs into the target language are enlisted, while the second part presents the main strategies employed in the prepared translations.

10 CFR 835.605 - Labeling items and containers.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Labeling items and containers. 835.605 Section 835.605... items and containers. Except as provided at § 835.606, each item or container of radioactive material... information to permit individuals handling, using, or working in the vicinity of the items or containers to...

Obtaining a Proportional Allocation by Deleting Items

NARCIS (Netherlands)

Dorn, B.; de Haan, R.; Schlotter, I.; Röthe, J.

2017-01-01

We consider the following control problem on fair allocation of indivisible goods. Given a set I of items and a set of agents, each having strict linear preference over the items, we ask for a minimum subset of the items whose deletion guarantees the existence of a proportional allocation in the

Control of Suspect/Counterfeit and Defective Items

Energy Technology Data Exchange (ETDEWEB)

Sheriff, Marnelle L.

2013-09-03

This procedure implements portions of the requirements of MSC-MP-599, Quality Assurance Program Description. It establishes the Mission Support Alliance (MSA) practices for minimizing the introduction of and identifying, documenting, dispositioning, reporting, controlling, and disposing of suspect/counterfeit and defective items (S/CIs). employees whose work scope relates to Safety Systems (i.e., Safety Class [SC] or Safety Significant [SS] items), non-safety systems and other applications (i.e., General Service [GS]) where engineering has determined that their use could result in a potential safety hazard. MSA implements an effective Quality Assurance (QA) Program providing a comprehensive network of controls and verification providing defense-in-depth by preventing the introduction of S/CIs through the design, procurement, construction, operation, maintenance, and modification of processes. This procedure focuses on those safety systems, and other systems, including critical load paths of lifting equipment, where the introduction of S/CIs would have the greatest potential for creating unsafe conditions.

Effect of study context on item recollection.

Science.gov (United States)

Skinner, Erin I; Fernandes, Myra A

2010-07-01

We examined how visual context information provided during encoding, and unrelated to the target word, affected later recollection for words presented alone using a remember-know paradigm. Experiments 1A and 1B showed that participants had better overall memory-specifically, recollection-for words studied with pictures of intact faces than for words studied with pictures of scrambled or inverted faces. Experiment 2 replicated these results and showed that recollection was higher for words studied with pictures of faces than when no image accompanied the study word. In Experiment 3 participants showed equivalent memory for words studied with unique faces as for those studied with a repeatedly presented face. Results suggest that recollection benefits when visual context information high in meaningful content accompanies study words and that this benefit is not related to the uniqueness of the context. We suggest that participants use elaborative processes to integrate item and meaningful contexts into ensemble information, improving subsequent item recollection.

Item-Based Top-N Recommendation Algorithms

Science.gov (United States)

2003-01-20

basket of items, utilized by many e-commerce sites, cannot take advantage of pre-computed user-to-user similarities. Finally, even though the...not discriminate between items that are present in frequent itemsets and items that are not, while still maintaining the computational advantages of...453219 0.02% 7.74 ccard 42629 68793 398619 0.01% 9.35 ecommerce 6667 17491 91222 0.08% 13.68 em 8002 1648 769311 5.83% 96.14 ml 943 1682 100000 6.31

A Review of Classical Methods of Item Analysis.

Science.gov (United States)

French, Christine L.

Item analysis is a very important consideration in the test development process. It is a statistical procedure to analyze test items that combines methods used to evaluate the important characteristics of test items, such as difficulty, discrimination, and distractibility of the items in a test. This paper reviews some of the classical methods for…

Electronics. Criterion-Referenced Test (CRT) Item Bank.

Science.gov (United States)

Davis, Diane, Ed.

This document contains 519 criterion-referenced multiple choice and true or false test items for a course in electronics. The test item bank is designed to work with both the Vocational Instructional Management System (VIMS) and the Vocational Administrative Management System (VAMS) in Missouri. The items are grouped into 15 units covering the…

26 CFR 301.6501(o)-3 - Partnership items.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Partnership items. 301.6501(o)-3 Section 301... § 301.6501(o)-3 Partnership items. (a) Partnership item defined. For purposes of section 6501(o) (as it..., and § 301.6511(g)-1, the term “partnership item” means— (1) Any item required to be taken into account...

The Department of Energy`s Rocky Flats Plant: A guide to record series useful for health-related research. Volume I, introduction

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-01

This guide consists of seven volumes which describe records useful for conducting health-related research at the DOE`s Rocky Flats Plant. Volume I is an introduction, and the remaining six volumes are arranged by the following categories: administrative and general, facilities and equipment, production and materials handling, waste management, workplace and environmental monitoring, and employee occupational exposure and health. Volume I briefly describes the Epidemiologic Records Project and provides information on the methodology used to inventory and describe the records series contained in subsequent volumes. Volume II describes records concerning administrative functions and general information. Volume III describes records series relating to the construction and routine maintenance of plant buildings and the purchase and installation of equipment. Volume IV describes records pertaining to the inventory and production of nuclear materials and weapon components. Records series include materials inventories, manufacturing specifications, engineering orders, transfer and shipment records, and War Reserve Bomb Books. Volume V describes records series pertaining to the storage, handling, treatment, and disposal of radioactive, chemical, or mixed materials produced or used at Rocky Flats. Volume VI describes records series pertaining to monitoring of the workplace and of the environment outside of buildings onsite and offsite. Volume VII describes records series pertaining to the health and occupational exposures of employees and visitors.

A Balance Sheet for Educational Item Banking.

Science.gov (United States)

Hiscox, Michael D.

Educational item banking presents observers with a considerable paradox. The development of test items from scratch is viewed as wasteful, a luxury in times of declining resources. On the other hand, item banking has failed to become a mature technology despite large amounts of money and the efforts of talented professionals. The question of which…

Promoting cold-start items in recommender systems.

Science.gov (United States)

Liu, Jin-Hu; Zhou, Tao; Zhang, Zi-Ke; Yang, Zimo; Liu, Chuang; Li, Wei-Min

2014-01-01

As one of the major challenges, cold-start problem plagues nearly all recommender systems. In particular, new items will be overlooked, impeding the development of new products online. Given limited resources, how to utilize the knowledge of recommender systems and design efficient marketing strategy for new items is extremely important. In this paper, we convert this ticklish issue into a clear mathematical problem based on a bipartite network representation. Under the most widely used algorithm in real e-commerce recommender systems, the so-called item-based collaborative filtering, we show that to simply push new items to active users is not a good strategy. Interestingly, experiments on real recommender systems indicate that to connect new items with some less active users will statistically yield better performance, namely, these new items will have more chance to appear in other users' recommendation lists. Further analysis suggests that the disassortative nature of recommender systems contributes to such observation. In a word, getting in-depth understanding on recommender systems could pave the way for the owners to popularize their cold-start products with low costs.

Promoting Cold-Start Items in Recommender Systems

Science.gov (United States)

Liu, Jin-Hu; Zhou, Tao; Zhang, Zi-Ke; Yang, Zimo; Liu, Chuang; Li, Wei-Min

2014-01-01

As one of the major challenges, cold-start problem plagues nearly all recommender systems. In particular, new items will be overlooked, impeding the development of new products online. Given limited resources, how to utilize the knowledge of recommender systems and design efficient marketing strategy for new items is extremely important. In this paper, we convert this ticklish issue into a clear mathematical problem based on a bipartite network representation. Under the most widely used algorithm in real e-commerce recommender systems, the so-called item-based collaborative filtering, we show that to simply push new items to active users is not a good strategy. Interestingly, experiments on real recommender systems indicate that to connect new items with some less active users will statistically yield better performance, namely, these new items will have more chance to appear in other users' recommendation lists. Further analysis suggests that the disassortative nature of recommender systems contributes to such observation. In a word, getting in-depth understanding on recommender systems could pave the way for the owners to popularize their cold-start products with low costs. PMID:25479013

Mixed-Format Test Score Equating: Effect of Item-Type Multidimensionality, Length and Composition of Common-Item Set, and Group Ability Difference

Science.gov (United States)

Wang, Wei

2013-01-01

Mixed-format tests containing both multiple-choice (MC) items and constructed-response (CR) items are now widely used in many testing programs. Mixed-format tests often are considered to be superior to tests containing only MC items although the use of multiple item formats leads to measurement challenges in the context of equating conducted under…

Non-ignorable missingness item response theory models for choice effects in examinee-selected items.

Science.gov (United States)

Liu, Chen-Wei; Wang, Wen-Chung

2017-11-01

Examinee-selected item (ESI) design, in which examinees are required to respond to a fixed number of items in a given set, always yields incomplete data (i.e., when only the selected items are answered, data are missing for the others) that are likely non-ignorable in likelihood inference. Standard item response theory (IRT) models become infeasible when ESI data are missing not at random (MNAR). To solve this problem, the authors propose a two-dimensional IRT model that posits one unidimensional IRT model for observed data and another for nominal selection patterns. The two latent variables are assumed to follow a bivariate normal distribution. In this study, the mirt freeware package was adopted to estimate parameters. The authors conduct an experiment to demonstrate that ESI data are often non-ignorable and to determine how to apply the new model to the data collected. Two follow-up simulation studies are conducted to assess the parameter recovery of the new model and the consequences for parameter estimation of ignoring MNAR data. The results of the two simulation studies indicate good parameter recovery of the new model and poor parameter recovery when non-ignorable missing data were mistakenly treated as ignorable. © 2017 The British Psychological Society.

How French subjects describe well-being from food and eating habits? Development, item reduction and scoring definition of the Well-Being related to Food Questionnaire (Well-BFQ©).

Science.gov (United States)

Guillemin, I; Marrel, A; Arnould, B; Capuron, L; Dupuy, A; Ginon, E; Layé, S; Lecerf, J-M; Prost, M; Rogeaux, M; Urdapilleta, I; Allaert, F-A

2016-01-01

Providing well-being and maintaining good health are main objectives subjects seek from diet. This manuscript describes the development and preliminary validation of an instrument assessing well-being associated with food and eating habits in a general healthy population. Qualitative data from 12 groups of discussion (102 subjects) conducted with healthy subjects were used to develop the core of the Well-being related to Food Questionnaire (Well-BFQ). Twelve other groups of discussion with subjects with joint (n = 34), digestive (n = 32) or repetitive infection complaints (n = 30) were performed to develop items specific to these complaints. Five main themes emerged from the discussions and formed the modular backbone of the questionnaire: "Grocery shopping", "Cooking", "Dining places", "Commensality", "Eating and drinking". Each module has a common structure: items about subject's food behavior and items about immediate and short-term benefits. An additional theme - "Eating habits and health" - assesses subjects' beliefs about expected benefits of food and eating habits on health, disease prevention and protection, and quality of ageing. A preliminary validation was conducted with 444 subjects with balanced diet; non-balanced diet; and standard diet. The structure of the questionnaire was further determined using principal component analyses exploratory factor analyses, with confirmation of the sub-sections food behaviors, immediate benefits (pleasure, security, relaxation), direct short-term benefits (digestion and satiety, energy and psychology), and deferred long-term benefits (eating habits and health). Thirty-three subscales and 14 single items were further defined. Confirmatory analyses confirmed the structure, with overall moderate to excellent convergent and divergent validity and internal consistency reliability. The Well-BFQ is a unique, modular tool that comprehensively assesses the full picture of well-being related to food and eating habits in

Clusters of cultures: diversity in meaning of family value and gender role items across Europe.

Science.gov (United States)

van Vlimmeren, Eva; Moors, Guy B D; Gelissen, John P T M

2017-01-01

Survey data are often used to map cultural diversity by aggregating scores of attitude and value items across countries. However, this procedure only makes sense if the same concept is measured in all countries. In this study we argue that when (co)variances among sets of items are similar across countries, these countries share a common way of assigning meaning to the items. Clusters of cultures can then be observed by doing a cluster analysis on the (co)variance matrices of sets of related items. This study focuses on family values and gender role attitudes. We find four clusters of cultures that assign a distinct meaning to these items, especially in the case of gender roles. Some of these differences reflect response style behavior in the form of acquiescence. Adjusting for this style effect impacts on country comparisons hence demonstrating the usefulness of investigating the patterns of meaning given to sets of items prior to aggregating scores into cultural characteristics.

A Case Study on an Item Writing Process: Use of Test Specifications, Nature of Group Dynamics, and Individual Item Writers' Characteristics

Science.gov (United States)

Kim, Jiyoung; Chi, Youngshin; Huensch, Amanda; Jun, Heesung; Li, Hongli; Roullion, Vanessa

2010-01-01

This article discusses a case study on an item writing process that reflects on our practical experience in an item development project. The purpose of the article is to share our lessons from the experience aiming to demystify item writing process. The study investigated three issues that naturally emerged during the project: how item writers use…

Does Categorization Method Matter in Exploring Volume-Outcome Relation? A Multiple Categorization Methods Comparison in Coronary Artery Bypass Graft Surgery Surgical Site Infection.

Science.gov (United States)

Yu, Tsung-Hsien; Tung, Yu-Chi; Chung, Kuo-Piao

2015-08-01

Volume-infection relation studies have been published for high-risk surgical procedures, although the conclusions remain controversial. Inconsistent results may be caused by inconsistent categorization methods, the definitions of service volume, and different statistical approaches. The purpose of this study was to examine whether a relation exists between provider volume and coronary artery bypass graft (CABG) surgical site infection (SSI) using different categorization methods. A population-based cross-sectional multi-level study was conducted. A total of 10,405 patients who received CABG surgery between 2006 and 2008 in Taiwan were recruited. The outcome of interest was surgical site infection for CABG surgery. The associations among several patient, surgeon, and hospital characteristics was examined. The definition of surgeons' and hospitals' service volume was the cumulative CABG service volumes in the previous year for each CABG operation and categorized by three types of approaches: Continuous, quartile, and k-means clustering. The results of multi-level mixed effects modeling showed that hospital volume had no association with SSI. Although the relation between surgeon volume and surgical site infection was negative, it was inconsistent among the different categorization methods. Categorization of service volume is an important issue in volume-infection study. The findings of the current study suggest that different categorization methods might influence the relation between volume and SSI. The selection of an optimal cutoff point should be taken into account for future research.

A comparison of discriminant logistic regression and Item Response Theory Likelihood-Ratio Tests for Differential Item Functioning (IRTLRDIF) in polytomous short tests.

Science.gov (United States)

Hidalgo, María D; López-Martínez, María D; Gómez-Benito, Juana; Guilera, Georgina

2016-01-01

Short scales are typically used in the social, behavioural and health sciences. This is relevant since test length can influence whether items showing DIF are correctly flagged. This paper compares the relative effectiveness of discriminant logistic regression (DLR) and IRTLRDIF for detecting DIF in polytomous short tests. A simulation study was designed. Test length, sample size, DIF amount and item response categories number were manipulated. Type I error and power were evaluated. IRTLRDIF and DLR yielded Type I error rates close to nominal level in no-DIF conditions. Under DIF conditions, Type I error rates were affected by test length DIF amount, degree of test contamination, sample size and number of item response categories. DLR showed a higher Type I error rate than did IRTLRDIF. Power rates were affected by DIF amount and sample size, but not by test length. DLR achieved higher power rates than did IRTLRDIF in very short tests, although the high Type I error rate involved means that this result cannot be taken into account. Test length had an important impact on the Type I error rate. IRTLRDIF and DLR showed a low power rate in short tests and with small sample sizes.

No Retrieval-Induced Forgetting Using Item-Specific Independent Cues: Evidence against a General Inhibitory Account

Science.gov (United States)

Camp, Gino; Pecher, Diane; Schmidt, Henk G.

2007-01-01

Retrieval practice with particular items from memory can impair the recall of related items on a later memory test. This retrieval-induced forgetting effect has been ascribed to inhibitory processes (M. C. Anderson & B. A. Spellman, 1995). A critical finding that distinguishes inhibitory from interference explanations is that forgetting is found…

Calorie Changes in Large Chain Restaurants: Declines in New Menu Items but Room for Improvement.

Science.gov (United States)

Bleich, Sara N; Wolfson, Julia A; Jarlenski, Marian P

2016-01-01

Large chain restaurants reduced the number of calories in newly introduced menu items in 2013 by about 60 calories (or 12%) relative to 2012. This paper describes trends in calories available in large U.S. chain restaurants to understand whether previously documented patterns persist. Data (a census of items for included restaurants) were obtained from the MenuStat project. This analysis included 66 of the 100 largest U.S. restaurants that are available in all three of the data years (2012-2014; N=23,066 items). Generalized linear models were used to examine: (1) per-item calorie changes from 2012 to 2014 among items on the menu in all years; and (2) mean calories in new items in 2013 and 2014 compared with items on the menu in 2012 only. Data were analyzed in 2014. Overall, calories in newly introduced menu items declined by 71 (or 15%) from 2012 to 2013 (p=0.001) and by 69 (or 14%) from 2012 to 2014 (p=0.03). These declines were concentrated mainly in new main course items (85 fewer calories in 2013 and 55 fewer calories in 2014; p=0.01). Although average calories in newly introduced menu items are declining, they are higher than items common to the menu in all 3 years. No differences in mean calories among items on menus in 2012, 2013, or 2014 were found. The previously observed declines in newly introduced menu items among large restaurant chains have been maintained, which suggests the beginning of a trend toward reducing calories. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Significance of breast boost volume changes during radiotherapy in relation to current clinical interobserver variations

International Nuclear Information System (INIS)

Hurkmans, Coen; Admiraal, Marjan; Sangen, Maurice van der; Dijkmans, Ingrid

2009-01-01

Background and purpose: Nowadays, many departments introduce CT images for breast irradiation techniques, aiming to obtain a better accuracy in the definition of the relevant target volumes. However, the definition of the breast boost volume based on CT images requires further investigation, because it may not only vary between observers, but it may also change during the course of treatment. This study aims to quantify the variability of the CT based visible boost volume (VBV) during the course of treatment in relation to the variability between observers. Materials and methods: Ten patients with stage T1-2 invasive breast cancer treated with breast conservative surgery and post surgical radiotherapy were included in this study. In addition to the regular planning CT which is obtained several days prior to radiotherapy, three additional CT scans were acquired 3, 5 and 7 weeks after the planning CT scan. Four radiation oncologists delineated the VBV in all scans. Conformity of the delineations was analysed both between observers, and between scans taken at different periods of the radiotherapy treatment. Results: The VBV averaged over all patients decreased during the course of the treatment from an initial 40 cm 3 to 28 cm 3 , 27 cm 3 and 25 cm 3 after 3, 5 and 7 weeks, respectively. Assuming the VBV to be spherical, this corresponds to a reduction in diameter of 5-6 mm. More detailed analysis revealed that this reduction was more pronounced when radiotherapy started within 30 days after surgery. These boost volume changes over time were found to be significant (p = 0.02) even in the presence of interobserver variations. Moreover, the conformity index (CI) for the volume changes was of the same magnitude as the conformity index for the interobserver variation (0.25 and 0.31, respectively). Conclusions: Breast boost volume variations during a course of radiotherapy are significant in relation to current clinical interobserver variations. This is an important

Automated Item Generation with Recurrent Neural Networks.

Science.gov (United States)

von Davier, Matthias

2018-03-12

Utilizing technology for automated item generation is not a new idea. However, test items used in commercial testing programs or in research are still predominantly written by humans, in most cases by content experts or professional item writers. Human experts are a limited resource and testing agencies incur high costs in the process of continuous renewal of item banks to sustain testing programs. Using algorithms instead holds the promise of providing unlimited resources for this crucial part of assessment development. The approach presented here deviates in several ways from previous attempts to solve this problem. In the past, automatic item generation relied either on generating clones of narrowly defined item types such as those found in language free intelligence tests (e.g., Raven's progressive matrices) or on an extensive analysis of task components and derivation of schemata to produce items with pre-specified variability that are hoped to have predictable levels of difficulty. It is somewhat unlikely that researchers utilizing these previous approaches would look at the proposed approach with favor; however, recent applications of machine learning show success in solving tasks that seemed impossible for machines not too long ago. The proposed approach uses deep learning to implement probabilistic language models, not unlike what Google brain and Amazon Alexa use for language processing and generation.

Fatty acid intake in relation to reproductive hormones and testicular volume among young healthy men

Institute of Scientific and Technical Information of China (English)

Lidia Mínguez-Alarcón; Jorge E Chavarro; Jaime Mendiola; Manuela Roca; Cigdem Tanrikut; Jesús Vioque; Niels Jørgensen; Alberto M Torres-Cantero

2017-01-01

Emerging evidence suggests that dietary fats may inlfuence testicular function. However, most of the published literature on this ifeld has used semen quality parameters as the only proxy for testicular function. We examined the association of fat intake with circulating reproductive hormone levels and testicular volume among healthy young Spanish men. This is a cross‑sectional study among 209 healthy male volunteers conducted between October 2010 and November 2011 in Murcia Region of Spain. Participants completed questionnaires on lifestyle, diet, and smoking, and each underwent a physical examination, and provided a blood sample. Linear regression was used to examine the association between each fatty acid type and reproductive hormone levels and testicular volumes. Monounsaturated fatty acids intake was inversely associated with serum blood levels of calculated free testosterone, total testosterone, and inhibin B. A positive association was observed between the intake of polyunsaturated fatty acids, particularly of omega‑6 polyunsaturated fatty acids, and luteinizing hormone concentrations. In addition, the intake of trans fatty acids was associated with lower total testosterone and calculated free testosterone concentrations (Ptrend=0.01 and 0.02, respectively). The intake of omega‑3 polyunsaturated fatty acids was positively related to testicular volume while the intake of omega‑6 polyunsaturated fatty acids and trans fatty acids was inversely related to testicular volume. These data suggest that fat intake, and particularly intake of omega 3, omega 6, and trans fatty acids, may inlfuence testicular function.

Fatty acid intake in relation to reproductive hormones and testicular volume among young healthy men

Directory of Open Access Journals (Sweden)

Lidia Mínguez-Alarcón

2017-01-01

Full Text Available Emerging evidence suggests that dietary fats may influence testicular function. However, most of the published literature on this field has used semen quality parameters as the only proxy for testicular function. We examined the association of fat intake with circulating reproductive hormone levels and testicular volume among healthy young Spanish men. This is a cross-sectional study among 209 healthy male volunteers conducted between October 2010 and November 2011 in Murcia Region of Spain. Participants completed questionnaires on lifestyle, diet, and smoking, and each underwent a physical examination, and provided a blood sample. Linear regression was used to examine the association between each fatty acid type and reproductive hormone levels and testicular volumes. Monounsaturated fatty acids intake was inversely associated with serum blood levels of calculated free testosterone, total testosterone, and inhibin B. A positive association was observed between the intake of polyunsaturated fatty acids, particularly of omega-6 polyunsaturated fatty acids, and luteinizing hormone concentrations. In addition, the intake of trans fatty acids was associated with lower total testosterone and calculated free testosterone concentrations (P trend = 0.01 and 0.02, respectively. The intake of omega-3 polyunsaturated fatty acids was positively related to testicular volume while the intake of omega-6 polyunsaturated fatty acids and trans fatty acids was inversely related to testicular volume. These data suggest that fat intake, and particularly intake of omega 3, omega 6, and trans fatty acids, may influence testicular function.

Relations between various measures of iodine intake and thyroid volume, thyroid nodularity, and serum thyroglobulin

DEFF Research Database (Denmark)

Rasmussen, Lone Banke; Ovesen, L.; Bulow, I.

2002-01-01

sought to identify, if possible, groups at risk of thyroid disease because of their food choices. Design: This cohort study included 4649 randomly selected subjects with mild-to-moderate iodine deficiency; the subjects lived in 2 cities in Denmark. Iodine intake was estimated by using a food...... some measures of iodine intake were significantly related to the prevalence of thyroid nodules. Conclusions: Even in a geographic area where mild iodine deficiency is common, a significant relation between iodine intake and thyroid volume was found. All measures of iodine intake, except iodine......Background: Iodine intake can be measured in various ways, and each method may have advantages and disadvantages. Objective: We sought to investigate the potential associations of various measures of iodine intake with thyroid volume, prevalence of thyroid nodules, and serum thyroglobulin. We also...

The Protective Behavioral Strategies for Marijuana Scale: Further examination using item response theory.

Science.gov (United States)

Pedersen, Eric R; Huang, Wenjing; Dvorak, Robert D; Prince, Mark A; Hummer, Justin F

2017-08-01

Given recent state legislation legalizing marijuana for recreational purposes and majority popular opinion favoring these laws, we developed the Protective Behavioral Strategies for Marijuana scale (PBSM) to identify strategies that may mitigate the harms related to marijuana use among those young people who choose to use the drug. In the current study, we expand on the initial exploratory study of the PBSM to further validate the measure with a large and geographically diverse sample (N = 2,117; 60% women, 30% non-White) of college students from 11 different universities across the United States. We sought to develop a psychometrically sound item bank for the PBSM and to create a short assessment form that minimizes respondent burden and time. Quantitative item analyses, including exploratory and confirmatory factor analyses with item response theory (IRT) and evaluation of differential item functioning (DIF), revealed an item bank of 36 items that was examined for unidimensionality and good content coverage, as well as a short form of 17 items that is free of bias in terms of gender (men vs. women), race (White vs. non-White), ethnicity (Hispanic vs. non-Hispanic), and recreational marijuana use legal status (state recreational marijuana was legal for 25.5% of participants). We also provide a scoring table for easy transformation from sum scores to IRT scale scores. The PBSM item bank and short form associated strongly and negatively with past month marijuana use and consequences. The measure may be useful to researchers and clinicians conducting intervention and prevention programs with young adults. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Modeling Item-Level and Step-Level Invariance Effects in Polytomous Items Using the Partial Credit Model

Science.gov (United States)

Gattamorta, Karina A.; Penfield, Randall D.; Myers, Nicholas D.

2012-01-01

Measurement invariance is a common consideration in the evaluation of the validity and fairness of test scores when the tested population contains distinct groups of examinees, such as examinees receiving different forms of a translated test. Measurement invariance in polytomous items has traditionally been evaluated at the item-level,…

Framing of mobility items: a source of poor agreement between preference-based health-related quality of life instruments in a population of individuals receiving assisted ventilation.

Science.gov (United States)

Hannan, Liam M; Whitehurst, David G T; Bryan, Stirling; Road, Jeremy D; McDonald, Christine F; Berlowitz, David J; Howard, Mark E

2017-06-01

To explore the influence of descriptive differences in items evaluating mobility on index scores generated from two generic preference-based health-related quality of life (HRQoL) instruments. The study examined cross-sectional data from a postal survey of individuals receiving assisted ventilation in two state/province-wide home mechanical ventilation services, one in British Columbia, Canada and the other in Victoria, Australia. The Assessment of Quality of Life 8-dimension (AQoL-8D) and the EQ-5D-5L were included in the data collection. Graphical illustrations, descriptive statistics, and measures of agreement [intraclass correlation coefficients (ICCs) and Bland-Altman plots] were examined using index scores derived from both instruments. Analyses were performed on the full sample as well as subgroups defined according to respondents' self-reported ability to walk. Of 868 individuals receiving assisted ventilation, 481 (55.4%) completed the questionnaire. Mean index scores were 0.581 (AQoL-8D) and 0.566 (EQ-5D-5L) with 'moderate' agreement demonstrated between the two instruments (ICC = 0.642). One hundred fifty-nine (33.1%) reported level 5 ('I am unable to walk about') on the EQ-5D-5L Mobility item. The walking status of respondents had a marked influence on the comparability of index scores, with a larger mean difference (0.206) and 'slight' agreement (ICC = 0.386) observed when the non-ambulant subgroup was evaluated separately. This study provides further evidence that between-measure discrepancies between preference-based HRQoL instruments are related in part to the framing of mobility-related items. Longitudinal studies are necessary to determine the responsiveness of preference-based HRQoL instruments in cohorts that include non-ambulant individuals.

Ancient Item Spoilage Ritual Used in Nomadic Burial Rite

Directory of Open Access Journals (Sweden)

Beisenov Arman Z.

2017-07-01

Full Text Available The article considers the findings of items in ancient burials which were intentionally spoiled prior to deposition in graves. This tradition was widely spread both in terms of chronology and geography, and therefore cannot be attributed to any individual cultures or regions. The authors present new information on the ritual obtained during an investigation of Borsyk burial mound of the Middle Sarmatian period located in West Kazakhstan. The central grave of barrow 6 contained a heavily damaged bronze cauldron. The grave was looted in antiquity. Individual scattered bones of a human skeleton and minor gold foil adornments from the ceremonial dress of a nobleman were discovered in the grave. The authors suggest that the cauldron was intentionally deformed by the participants of an ancient mortuary and memorial ritual. According to the principal hypothesis concerning the essence of this ritual, spoilage of the items was related to the idea of assign the items with “different” and “transcendent” properties, which resulted from the necessity of burying the owner. Cauldrons played an important role in the life of steppe leaders. The authors assume a sacral nature of the use of cauldrons in the culture of steppe peoples associated with feasts, battles, and sacred hunting. Perhaps, there was a tradition of burying cauldrons together with their owners after spoiling the items in view of the concept of the other world and the role of a heroic leader therein.

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

Quality assurance in the manufacture of items for nuclear power plants

International Nuclear Information System (INIS)

1981-01-01

This Safety Guide provides requirements and recommendations related to the establishment and implementation of a quality assurance programme for those organizations involved in the manufacture of items affecting the safety of nuclear power plants. The quality-assurance-related functions of a manufacturer may include activities such as designing, purchasing, fabricating, handling, shipping, storing, cleaning, inspecting, testing, modifying, repairing and maintaining. It is not the aim of the present Guide, which supplements the above-mentioned Code of Practice, to provide rules related to the quality assurance programme for the design of items. Manufacturers that generate designs shall follow the requirements and recommendations contained in the Safety Guide on Quality Assurance in the Design of Nuclear Power Plants (IAEA Safety Series No. 50-SG-QA6). All these publications form part of the Agency's programme, referred to as the NUSS programme, for establishing Codes of Practice and Safety Guides relating to land-based stationary thermal neutron power plants. A Provisional List of NUSS Programme Titles will be found at the end of this publication

Work ability as prognostic risk marker of disability pension : Single-item work ability score versus multi-item work ability index

NARCIS (Netherlands)

Roelen, C.A.M.; Rhenen, van W.; Groothoff, J.W.; Klink, van der J.J.L.; Twisk, W.R.; Heymans, M.W.

2014-01-01

Work ability predicts future disability pension (DP). A single-item work ability score (WAS) is emerging as a measure for work ability. This study compared single-item WAS with the multi-item work ability index (WAI) in its ability to identify workers at risk of DP.

CERN Running Club – Sale of Items

CERN Multimedia

CERN Running club

2018-01-01

The CERN Running Club is organising a sale of items  on 26 June from 11:30 – 13:00 in the entry area of Restaurant 2 (504 R-202). The items for sale are souvenir prizes of past Relay Races and comprise: Backpacks, thermos, towels, gloves & caps, lamps, long sleeve winter shirts and windproof vest. All items will be sold at 5 CHF.

Work ability as prognostic risk marker of disability pension: single-item work ability score versus multi-item work ability index

NARCIS (Netherlands)

Roelen, C.A.M.; van Rhenen, W.; Groothoff, J.W.; van der Klink, J.J.L.; Twisk, J.W.R.; Heymans, M.W.

2014-01-01

Objectives Work ability predicts future disability pension (DP). A single-item work ability score (WAS) is emerging as a measure for work ability. This study compared single-item WAS with the multi-item work ability index (WAI) in its ability to identify workers at risk of DP. Methods This

Work ability as prognostic risk marker of disability pension : single-item work ability score versus multi-item work ability index

NARCIS (Netherlands)

Roelen, Corne A. M.; van Rhenen, Willem; Groothoff, Johan W.; van der Klink, Jac J. L.; Twisk, Jos W. R.; Heymans, Martijn W.

Objectives Work ability predicts future disability pension (DP). A single-item work ability score (WAS) is emerging as a measure for work ability. This study compared single-item WAS with the multi-item work ability index (WAI) in its ability to identify workers at risk of DP. Methods This

Development and validation of an item response theory-based Social Responsiveness Scale short form.

Science.gov (United States)

Sturm, Alexandra; Kuhfeld, Megan; Kasari, Connie; McCracken, James T

2017-09-01

Research and practice in autism spectrum disorder (ASD) rely on quantitative measures, such as the Social Responsiveness Scale (SRS), for characterization and diagnosis. Like many ASD diagnostic measures, SRS scores are influenced by factors unrelated to ASD core features. This study further interrogates the psychometric properties of the SRS using item response theory (IRT), and demonstrates a strategy to create a psychometrically sound short form by applying IRT results. Social Responsiveness Scale analyses were conducted on a large sample (N = 21,426) of youth from four ASD databases. Items were subjected to item factor analyses and evaluation of item bias by gender, age, expressive language level, behavior problems, and nonverbal IQ. Item selection based on item psychometric properties, DIF analyses, and substantive validity produced a reduced item SRS short form that was unidimensional in structure, highly reliable (α = .96), and free of gender, age, expressive language, behavior problems, and nonverbal IQ influence. The short form also showed strong relationships with established measures of autism symptom severity (ADOS, ADI-R, Vineland). Degree of association between all measures varied as a function of expressive language. Results identified specific SRS items that are more vulnerable to non-ASD-related traits. The resultant 16-item SRS short form may possess superior psychometric properties compared to the original scale and emerge as a more precise measure of ASD core symptom severity, facilitating research and practice. Future research using IRT is needed to further refine existing measures of autism symptomatology. © 2017 Association for Child and Adolescent Mental Health.

Binomial test models and item difficulty

NARCIS (Netherlands)

van der Linden, Willem J.

1979-01-01

In choosing a binomial test model, it is important to know exactly what conditions are imposed on item difficulty. In this paper these conditions are examined for both a deterministic and a stochastic conception of item responses. It appears that they are more restrictive than is generally

Life sciences payload definition and integration study, task C and D. Volume 4: Preliminary equipment item specification catalog

Science.gov (United States)

1973-01-01

A specification catalog to define the equipment to be used for conducting life sciences experiments in a space laboratory is presented. The specification sheets list the purpose of the equipment item, and any specific technical requirements which can be identified. The status of similar hardware for ground use is stated with comments regarding modifications required to achieve spaceflight qualified hardware. Pertinent sketches, commercial catalog sheets, or drawings of the applicable equipment are included.

Beneficial effects of semantic memory support on older adults' episodic memory: Differential patterns of support of item and associative information.

Science.gov (United States)

Mohanty, Praggyan Pam; Naveh-Benjamin, Moshe; Ratneshwar, Srinivasan

2016-02-01

The effects of two types of semantic memory support-meaningfulness of an item and relatedness between items-in mitigating age-related deficits in item and associative, memory are examined in a marketing context. In Experiment 1, participants studied less (vs. more) meaningful brand logo graphics (pictures) paired with meaningful brand names (words) and later were assessed by item (old/new) and associative (intact/recombined) memory recognition tests. Results showed that meaningfulness of items eliminated age deficits in item memory, while equivalently boosting associative memory for older and younger adults. Experiment 2, in which related and unrelated brand logo graphics and brand name pairs served as stimuli, revealed that relatedness between items eliminated age deficits in associative memory, while improving to the same degree item memory in older and younger adults. Experiment 2 also provided evidence for a probable boundary condition that could reconcile seemingly contradictory extant results. Overall, these experiments provided evidence that although the two types of semantic memory support can improve both item and associative memory in older and younger adults, older adults' memory deficits can be eliminated when the type of support provided is compatible with the type of information required to perform well on the test. (c) 2016 APA, all rights reserved).

Vegetable parenting practices scale: Item response modeling analyses

Science.gov (United States)

Our objective was to evaluate the psychometric properties of a vegetable parenting practices scale using multidimensional polytomous item response modeling which enables assessing item fit to latent variables and the distributional characteristics of the items in comparison to the respondents. We al...

Efficient Algorithms for Segmentation of Item-Set Time Series

Science.gov (United States)

Chundi, Parvathi; Rosenkrantz, Daniel J.

We propose a special type of time series, which we call an item-set time series, to facilitate the temporal analysis of software version histories, email logs, stock market data, etc. In an item-set time series, each observed data value is a set of discrete items. We formalize the concept of an item-set time series and present efficient algorithms for segmenting a given item-set time series. Segmentation of a time series partitions the time series into a sequence of segments where each segment is constructed by combining consecutive time points of the time series. Each segment is associated with an item set that is computed from the item sets of the time points in that segment, using a function which we call a measure function. We then define a concept called the segment difference, which measures the difference between the item set of a segment and the item sets of the time points in that segment. The segment difference values are required to construct an optimal segmentation of the time series. We describe novel and efficient algorithms to compute segment difference values for each of the measure functions described in the paper. We outline a dynamic programming based scheme to construct an optimal segmentation of the given item-set time series. We use the item-set time series segmentation techniques to analyze the temporal content of three different data sets—Enron email, stock market data, and a synthetic data set. The experimental results show that an optimal segmentation of item-set time series data captures much more temporal content than a segmentation constructed based on the number of time points in each segment, without examining the item set data at the time points, and can be used to analyze different types of temporal data.

Overview of Classical Test Theory and Item Response Theory for Quantitative Assessment of Items in Developing Patient-Reported Outcome Measures

Science.gov (United States)

Cappelleri, Joseph C.; Lundy, J. Jason; Hays, Ron D.

2014-01-01

Introduction The U.S. Food and Drug Administration’s patient-reported outcome (PRO) guidance document defines content validity as “the extent to which the instrument measures the concept of interest” (FDA, 2009, p. 12). “Construct validity is now generally viewed as a unifying form of validity for psychological measurements, subsuming both content and criterion validity” (Strauss & Smith, 2009, p. 7). Hence both qualitative and quantitative information are essential in evaluating the validity of measures. Methods We review classical test theory and item response theory approaches to evaluating PRO measures including frequency of responses to each category of the items in a multi-item scale, the distribution of scale scores, floor and ceiling effects, the relationship between item response options and the total score, and the extent to which hypothesized “difficulty” (severity) order of items is represented by observed responses. Conclusion Classical test theory and item response theory can be useful in providing a quantitative assessment of items and scales during the content validity phase of patient-reported outcome measures. Depending on the particular type of measure and the specific circumstances, either one or both approaches should be considered to help maximize the content validity of PRO measures. PMID:24811753

Frequency Distribution of Second Solid Cancer Locations in Relation to the Irradiated Volume Among 115 Patients Treated for Childhood Cancer

International Nuclear Information System (INIS)

Diallo, Ibrahima; Haddy, Nadia; Adjadj, Elisabeth; Samand, Akhtar; Quiniou, Eric; Chavaudra, Jean; Alziar, Iannis; Perret, Nathalie; Guerin, Sylvie; Lefkopoulos, Dimitri; Vathaire, Florent de

2009-01-01

Purpose: To provide better estimates of the frequency distribution of second malignant neoplasm (SMN) sites in relation to previous irradiated volumes, and better estimates of the doses delivered to these sites during radiotherapy (RT) of the first malignant neoplasm (FMN). Methods and Materials: The study focused on 115 patients who developed a solid SMN among a cohort of 4581 individuals. The homemade software package Dos E G was used to estimate the radiation doses delivered to SMN sites during RT of the FMN. Three-dimensional geometry was used to evaluate the distances between the irradiated volume, for RT delivered to each FMN, and the site of the subsequent SMN. Results: The spatial distribution of SMN relative to the irradiated volumes in our cohort was as follows: 12% in the central area of the irradiated volume, which corresponds to the planning target volume (PTV), 66% in the beam-bordering region (i.e., the area surrounding the PTV), and 22% in regions located more than 5 cm from the irradiated volume. At the SMN site, all dose levels ranging from almost zero to >75 Gy were represented. A peak SMN frequency of approximately 31% was identified in volumes that received <2.5 Gy. Conclusion: A greater volume of tissues receives low or intermediate doses in regions bordering the irradiated volume with modern multiple-beam RT arrangements. These results should be considered for risk-benefit evaluations of RT.

Is there an agreement among the items of the Korean physical therapist licensing examination, learning objectives of class subjects, and physical therapists' job descriptions?

Science.gov (United States)

Kang, Min-Hyeok; Kwon, Oh-Yun; Kim, Yong-Wook; Kim, Ji-Won; Kim, Tae-Ho; Oh, Tae-Young; Weon, Jong-Hyuk; Lee, Tae-Sik; Oh, Jae-Seop

2016-01-01

To determine the agreement among the items of the Korean physical therapist licensing examination, learning objectives of class subjects, and physical therapists' job descriptions. The main tasks of physical therapists were classified, and university courses related to the main tasks were also classified. Frequency analysis was used to determine the proportions of credits for the classified courses out of the total credits of major subjects, exam items related to the classified courses out of the total number of exam items, and universities that offer courses related to the Korean physical therapist licensing examination among the surveyed universities. The proportions of credits for clinical decision making and physical therapy diagnosis-related courses out of the total number credits for major subjects at universities were relatively low (2.06% and 2.58%, respectively). Although the main tasks of physical therapists are related to diagnosis and evaluation, the proportion of physiotherapy intervention-related items (35%) was higher than that of examination and evaluation-related items (25%) on the Korean physical therapist licensing examination. The percentages of universities that offer physical therapy diagnosis and clinical decision making-related courses were 58.62% and 68.97%, respectively. Both the proportion of physiotherapy diagnosis and evaluation-related items on the Korean physical therapist licensing examination, and the number of subjects related to clinical decision making and physical therapy diagnosis in the physical therapy curriculum, should be increased to ensure that the examination items and physical therapy curriculum reflect the practical tasks of physical therapists.

Sources of interference in item and associative recognition memory.

Science.gov (United States)

Osth, Adam F; Dennis, Simon

2015-04-01

A powerful theoretical framework for exploring recognition memory is the global matching framework, in which a cue's memory strength reflects the similarity of the retrieval cues being matched against the contents of memory simultaneously. Contributions at retrieval can be categorized as matches and mismatches to the item and context cues, including the self match (match on item and context), item noise (match on context, mismatch on item), context noise (match on item, mismatch on context), and background noise (mismatch on item and context). We present a model that directly parameterizes the matches and mismatches to the item and context cues, which enables estimation of the magnitude of each interference contribution (item noise, context noise, and background noise). The model was fit within a hierarchical Bayesian framework to 10 recognition memory datasets that use manipulations of strength, list length, list strength, word frequency, study-test delay, and stimulus class in item and associative recognition. Estimates of the model parameters revealed at most a small contribution of item noise that varies by stimulus class, with virtually no item noise for single words and scenes. Despite the unpopularity of background noise in recognition memory models, background noise estimates dominated at retrieval across nearly all stimulus classes with the exception of high frequency words, which exhibited equivalent levels of context noise and background noise. These parameter estimates suggest that the majority of interference in recognition memory stems from experiences acquired before the learning episode. (c) 2015 APA, all rights reserved).

Planck/SDSS Cluster Mass and Gas Scaling Relations for a Volume-Complete redMaPPer Sample

Science.gov (United States)

Jimeno, Pablo; Diego, Jose M.; Broadhurst, Tom; De Martino, I.; Lazkoz, Ruth

2018-04-01

Using Planck satellite data, we construct Sunyaev-Zel'dovich (SZ) gas pressure profiles for a large, volume-complete sample of optically selected clusters. We have defined a sample of over 8,000 redMaPPer clusters from the Sloan Digital Sky Survey (SDSS), within the volume-complete redshift region 0.100 trend towards larger break radius with increasing cluster mass. Our SZ-based masses fall ˜16% below the mass-richness relations from weak lensing, in a similar fashion as the "hydrostatic bias" related with X-ray derived masses. Finally, we derive a tight Y500-M500 relation over a wide range of cluster mass, with a power law slope equal to 1.70 ± 0.07, that agrees well with the independent slope obtained by the Planck team with an SZ-selected cluster sample, but extends to lower masses with higher precision.

CTTITEM: SAS macro and SPSS syntax for classical item analysis.

Science.gov (United States)

Lei, Pui-Wa; Wu, Qiong

2007-08-01

This article describes the functions of a SAS macro and an SPSS syntax that produce common statistics for conventional item analysis including Cronbach's alpha, item difficulty index (p-value or item mean), and item discrimination indices (D-index, point biserial and biserial correlations for dichotomous items and item-total correlation for polytomous items). These programs represent an improvement over the existing SAS and SPSS item analysis routines in terms of completeness and user-friendliness. To promote routine evaluations of item qualities in instrument development of any scale, the programs are available at no charge for interested users. The program codes along with a brief user's manual that contains instructions and examples are downloadable from suen.ed.psu.edu/-pwlei/plei.htm.

Quality assurance in the procurement of items and services for nuclear power plants

International Nuclear Information System (INIS)

1979-01-01

This Safety Guide was prepared as part of the Agency's programme, referred to as the NUSS programme, for establishing Codes of Practice and Safety Guides relating to nuclear power plants. It supplements the Agency's Code of Practice on Quality Assurance for Safety in Nuclear Power Plants (Safety Series No.50-C-QA), which states requirements for the control of procurement of items and services which are important to the safety of nuclear power plants, for the purpose of achieving quality. The establishment and implementation of controls over the procurement process provide a basis for establishing an appropriate level of confidence that the activities undertaken during procurement of items and services have been performed in accordance with the principles of quality assurance expressed in the Code, and that the required quality of items and services has been achieved. The purchaser, in establishing control over procurement, shall ensure that the quality criteria, quality level, and other quality requirements specified for the particular item or service are taken into account

Item Response Theory Applied to Factors Affecting the Patient Journey Towards Hearing Rehabilitation

Science.gov (United States)

Chenault, Michelene; Berger, Martijn; Kremer, Bernd; Anteunis, Lucien

2016-01-01

To develop a tool for use in hearing screening and to evaluate the patient journey towards hearing rehabilitation, responses to the hearing aid rehabilitation questionnaire scales aid stigma, pressure, and aid unwanted addressing respectively hearing aid stigma, experienced pressure from others; perceived hearing aid benefit were evaluated with item response theory. The sample was comprised of 212 persons aged 55 years or more; 63 were hearing aid users, 64 with and 85 persons without hearing impairment according to guidelines for hearing aid reimbursement in the Netherlands. Bias was investigated relative to hearing aid use and hearing impairment within the differential test functioning framework. Items compromising model fit or demonstrating differential item functioning were dropped. The aid stigma scale was reduced from 6 to 4, the pressure scale from 7 to 4, and the aid unwanted scale from 5 to 4 items. This procedure resulted in bias-free scales ready for screening purposes and application to further understand the help-seeking process of the hearing impaired. PMID:28028428

Pattern analysis of total item score and item response of the Kessler Screening Scale for Psychological Distress (K6 in a nationally representative sample of US adults

Directory of Open Access Journals (Sweden)

Shinichiro Tomitaka

2017-02-01

Full Text Available Background Several recent studies have shown that total scores on depressive symptom measures in a general population approximate an exponential pattern except for the lower end of the distribution. Furthermore, we confirmed that the exponential pattern is present for the individual item responses on the Center for Epidemiologic Studies Depression Scale (CES-D. To confirm the reproducibility of such findings, we investigated the total score distribution and item responses of the Kessler Screening Scale for Psychological Distress (K6 in a nationally representative study. Methods Data were drawn from the National Survey of Midlife Development in the United States (MIDUS, which comprises four subsamples: (1 a national random digit dialing (RDD sample, (2 oversamples from five metropolitan areas, (3 siblings of individuals from the RDD sample, and (4 a national RDD sample of twin pairs. K6 items are scored using a 5-point scale: “none of the time,” “a little of the time,” “some of the time,” “most of the time,” and “all of the time.” The pattern of total score distribution and item responses were analyzed using graphical analysis and exponential regression model. Results The total score distributions of the four subsamples exhibited an exponential pattern with similar rate parameters. The item responses of the K6 approximated a linear pattern from “a little of the time” to “all of the time” on log-normal scales, while “none of the time” response was not related to this exponential pattern. Discussion The total score distribution and item responses of the K6 showed exponential patterns, consistent with other depressive symptom scales.

Negative effects of item repetition on source memory

OpenAIRE

Kim, Kyungmi; Yi, Do-Joon; Raye, Carol L.; Johnson, Marcia K.

2012-01-01

In the present study, we explored how item repetition affects source memory for new item–feature associations (picture–location or picture–color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item re...

Predicting Structure-Function Relations and Survival following Surgical and Bronchoscopic Lung Volume Reduction Treatment of Emphysema.

Science.gov (United States)

Mondoñedo, Jarred R; Suki, Béla

2017-02-01

Lung volume reduction surgery (LVRS) and bronchoscopic lung volume reduction (bLVR) are palliative treatments aimed at reducing hyperinflation in advanced emphysema. Previous work has evaluated functional improvements and survival advantage for these techniques, although their effects on the micromechanical environment in the lung have yet to be determined. Here, we introduce a computational model to simulate a force-based destruction of elastic networks representing emphysema progression, which we use to track the response to lung volume reduction via LVRS and bLVR. We find that (1) LVRS efficacy can be predicted based on pre-surgical network structure; (2) macroscopic functional improvements following bLVR are related to microscopic changes in mechanical force heterogeneity; and (3) both techniques improve aspects of survival and quality of life influenced by lung compliance, albeit while accelerating disease progression. Our model predictions yield unique insights into the microscopic origins underlying emphysema progression before and after lung volume reduction.

38 CFR 3.1606 - Transportation items.

Science.gov (United States)

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Transportation items. 3... Burial Benefits § 3.1606 Transportation items. The transportation costs of those persons who come within... shipment. (6) Cost of transportation by common carrier including amounts paid as Federal taxes. (7) Cost of...

Assessing difference between classical test theory and item ...

African Journals Online (AJOL)

Assessing difference between classical test theory and item response theory methods in scoring primary four multiple choice objective test items. ... All research participants were ranked on the CTT number correct scores and the corresponding IRT item pattern scores from their performance on the PRISMADAT. Wilcoxon ...

The basics of item response theory using R

CERN Document Server

Baker, Frank B

2017-01-01

This graduate-level textbook is a tutorial for item response theory that covers both the basics of item response theory and the use of R for preparing graphical presentation in writings about the theory. Item response theory has become one of the most powerful tools used in test construction, yet one of the barriers to learning and applying it is the considerable amount of sophisticated computational effort required to illustrate even the simplest concepts. This text provides the reader access to the basic concepts of item response theory freed of the tedious underlying calculations. It is intended for those who possess limited knowledge of educational measurement and psychometrics. Rather than presenting the full scope of item response theory, this textbook is concise and practical and presents basic concepts without becoming enmeshed in underlying mathematical and computational complexities. Clearly written text and succinct R code allow anyone familiar with statistical concepts to explore and apply item re...

Exploring differential item functioning in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC

Directory of Open Access Journals (Sweden)

Pollard Beth

2012-12-01

Full Text Available Abstract Background The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC is a widely used patient reported outcome in osteoarthritis. An important, but frequently overlooked, aspect of validating health outcome measures is to establish if items exhibit differential item functioning (DIF. That is, if respondents have the same underlying level of an attribute, does the item give the same score in different subgroups or is it biased towards one subgroup or another. The aim of the study was to explore DIF in the Likert format WOMAC for the first time in a UK osteoarthritis population with respect to demographic, social, clinical and psychological factors. Methods The sample comprised a community sample of 763 people with osteoarthritis who participated in the Somerset and Avon Survey of Health. The WOMAC was explored for DIF by gender, age, social deprivation, social class, employment status, distress, body mass index and clinical factors. Ordinal regression models were used to identify DIF items. Results After adjusting for age, two items were identified for the physical functioning subscale as having DIF with age identified as the DIF factor for 2 items, gender for 1 item and body mass index for 1 item. For the WOMAC pain subscale, for people with hip osteoarthritis one item was identified with age-related DIF. The impact of the DIF items rarely had a significant effect on the conclusions of group comparisons. Conclusions Overall, the WOMAC performed well with only a small number of DIF items identified. However, as DIF items were identified in for the WOMAC physical functioning subscale it would be advisable to analyse data taking into account the possible impact of the DIF items when weight, gender or especially age effects, are the focus of interest in UK-based osteoarthritis studies. Similarly for the WOMAC pain subscale in people with hip osteoarthritis it would be worthwhile to analyse data taking into account the

Composite materials. Volume 3 - Engineering applications of composites. Volume 4 - Metallic matrix composites. Volume 8 - Structural design and analysis, Part 2

Science.gov (United States)

Noton, B. R. (Editor); Kreider, K. G.; Chamis, C. C.

1974-01-01

This volume discusses a vaety of applications of both low- and high-cost composite materials in a number of selected engineering fields. The text stresses the use of fiber-reinforced composites, along with interesting material systems used in the electrical and nuclear industries. As to technology transfer, a similarity is noted between many of the reasons responsible for the utilization of composites and those problems requiring urgent solution, such as mechanized fabrication processes and design for production. Features topics include road transportation, rail transportation, civil aircraft, space vehicles, builing industry, chemical plants, and appliances and equipment. The laminate orientation code devised by Air Force materials laboratory is included. Individual items are announced in this issue.

Effect of Differential Item Functioning on Test Equating

Science.gov (United States)

Kabasakal, Kübra Atalay; Kelecioglu, Hülya

2015-01-01

This study examines the effect of differential item functioning (DIF) items on test equating through multilevel item response models (MIRMs) and traditional IRMs. The performances of three different equating models were investigated under 24 different simulation conditions, and the variables whose effects were examined included sample size, test…

Beliefs that manifest through newspaper items in relation to peoples’ life challenges and their potential to enhance a sustainable learning environment in school science

Directory of Open Access Journals (Sweden)

Thapelo L. Mamiala

2013-12-01

Full Text Available The paper documents beliefs that manifest themselves through newspaper items and elaborates on their potential to enhance a sustainable learning environment in a school science lesson. “Learning environment” is depicted from different angles and includes virtual and real learning environments, school environments and classroom environments. Descriptive and item analyses were conducted on sixty-eight newspaper items that were identified. The nature of problems and prescriptions/solutions was categorised for each item and the paper further provides elaboration on the types of problems and recommended solutions. The results show that the “believed” structure contents in their newspaper items to catch the attention of the “believer”. Lessons on the power of belief must be learnt by school science teachers if they are to succeed in creating a sustainable learning environment with improved performance in school science.

Developing core elements and checklist items for global hospital antimicrobial stewardship programmes: a consensus approach.

Science.gov (United States)

Pulcini, C; Binda, F; Lamkang, A S; Trett, A; Charani, E; Goff, D A; Harbarth, S; Hinrichsen, S L; Levy-Hara, G; Mendelson, M; Nathwani, D; Gunturu, R; Singh, S; Srinivasan, A; Thamlikitkul, V; Thursky, K; Vlieghe, E; Wertheim, H; Zeng, M; Gandra, S; Laxminarayan, R

2018-04-03

With increasing global interest in hospital antimicrobial stewardship (AMS) programmes, there is a strong demand for core elements of AMS to be clearly defined on the basis of principles of effectiveness and affordability. To date, efforts to identify such core elements have been limited to Europe, Australia, and North America. The aim of this study was to develop a set of core elements and their related checklist items for AMS programmes that should be present in all hospitals worldwide, regardless of resource availability. A literature review was performed by searching Medline and relevant websites to retrieve a list of core elements and items that could have global relevance. These core elements and items were evaluated by an international group of AMS experts using a structured modified Delphi consensus procedure, using two-phased online in-depth questionnaires. The literature review identified seven core elements and their related 29 checklist items from 48 references. Fifteen experts from 13 countries in six continents participated in the consensus procedure. Ultimately, all seven core elements were retained, as well as 28 of the initial checklist items plus one that was newly suggested, all with ≥80% agreement; 20 elements and items were rephrased. This consensus on core elements for hospital AMS programmes is relevant to both high- and low-to-middle-income countries and could facilitate the development of national AMS stewardship guidelines and adoption by healthcare settings worldwide. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. All rights reserved.

The Voronoi volume and molecular representation of molar volume: equilibrium simple fluids.

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Hunjan, Jagtar Singh; Eu, Byung Chan

2010-04-07

The Voronoi volume of simple fluids was previously made use of in connection with volume transport phenomena in nonequilibrium simple fluids. To investigate volume transport phenomena, it is important to develop a method to compute the Voronoi volume of fluids in nonequilibrium. In this work, as a first step to this goal, we investigate the equilibrium limit of the nonequilibrium Voronoi volume together with its attendant related molar (molal) and specific volumes. It is proved that the equilibrium Voronoi volume is equivalent to the molar (molal) volume. The latter, in turn, is proved equivalent to the specific volume. This chain of equivalences provides an alternative procedure of computing the equilibrium Voronoi volume from the molar volume/specific volume. We also show approximate methods of computing the Voronoi and molar volumes from the information on the pair correlation function. These methods may be employed for their quick estimation, but also provide some aspects of the fluid structure and its relation to the Voronoi volume. The Voronoi volume obtained from computer simulations is fitted to a function of temperature and pressure in the region above the triple point but below the critical point. Since the fitting function is given in terms of reduced variables for the Lennard-Jones (LJ) model and the kindred volumes (i.e., specific and molar volumes) are in essence equivalent to the equation of state, the formula obtained is a reduced equation state for simple fluids obeying the LJ model potential in the range of temperature and pressure examined and hence can be used for other simple fluids.

Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume VII. Cryogenic system

International Nuclear Information System (INIS)

Poteat, T.J.

1982-01-01

This document, Volume VII EBT-P Cryogenic System Title I Design Report, describes the system that resulted from the Title I Preliminary Design effort. It is a self-contained document that can be read apart from the other Volumes comprising the EBT-P Title I Report. This document is a contract deliverable item and provides the detail necessary to support the Cryogenic System design contained in the EBT-P Baseline Design Data Book

Item bias detection in the Hospital Anxiety and Depression Scale using structural equation modeling: comparison with other item bias detection methods

NARCIS (Netherlands)

Verdam, M.G.E.; Oort, F.J.; Sprangers, M.A.G.

Purpose Comparison of patient-reported outcomes may be invalidated by the occurrence of item bias, also known as differential item functioning. We show two ways of using structural equation modeling (SEM) to detect item bias: (1) multigroup SEM, which enables the detection of both uniform and

ACER Chemistry Test Item Collection. ACER Chemtic Year 12.

Science.gov (United States)

Australian Council for Educational Research, Hawthorn.

The chemistry test item banks contains 225 multiple-choice questions suitable for diagnostic and achievement testing; a three-page teacher's guide; answer key with item facilities; an answer sheet; and a 45-item sample achievement test. Although written for the new grade 12 chemistry course in Victoria, Australia, the items are widely applicable.…

Psychometric validation of the Persian nine-item Internet Gaming Disorder Scale - Short Form: Does gender and hours spent online gaming affect the interpretations of item descriptions?

Science.gov (United States)

Wu, Tzu-Yi; Lin, Chung-Ying; Årestedt, Kristofer; Griffiths, Mark D; Broström, Anders; Pakpour, Amir H

2017-06-01

Background and aims The nine-item Internet Gaming Disorder Scale - Short Form (IGDS-SF9) is brief and effective to evaluate Internet Gaming Disorder (IGD) severity. Although its scores show promising psychometric properties, less is known about whether different groups of gamers interpret the items similarly. This study aimed to verify the construct validity of the Persian IGDS-SF9 and examine the scores in relation to gender and hours spent online gaming among 2,363 Iranian adolescents. Methods Confirmatory factor analysis (CFA) and Rasch analysis were used to examine the construct validity of the IGDS-SF9. The effects of gender and time spent online gaming per week were investigated by multigroup CFA and Rasch differential item functioning (DIF). Results The unidimensionality of the IGDS-SF9 was supported in both CFA and Rasch. However, Item 4 (fail to control or cease gaming activities) displayed DIF (DIF contrast = 0.55) slightly over the recommended cutoff in Rasch but was invariant in multigroup CFA across gender. Items 4 (DIF contrast = -0.67) and 9 (jeopardize or lose an important thing because of gaming activity; DIF contrast = 0.61) displayed DIF in Rasch and were non-invariant in multigroup CFA across time spent online gaming. Conclusions Given the Persian IGDS-SF9 was unidimensional, it is concluded that the instrument can be used to assess IGD severity. However, users of the instrument are cautioned concerning the comparisons of the sum scores of the IGDS-SF9 across gender and across adolescents spending different amounts of time online gaming.

Counterfeit and Fraudulent Items - Mitigating the risk

International Nuclear Information System (INIS)

Tannenbaum, Marc

2011-01-01

This presentation (slides) provides an overview of the industry's challenges and activities. Firstly, it outlines the differences between counterfeit, fraudulent, suspect, and also substandard items. Notice is given that items could be found not to meet the standard, but the difference in the intent to deceive with counterfeit and fraudulent items is the critical element. Examples from other industries are used which also rely heavily on the assurance of quality for safety. It also informs that EPRI has just completed a report in October 2009 in coordination with other US government agencies and industry organizations; this report, entitled Counterfeit, Substandard and Fraudulent Items, number 1019163, is available for free on the EPRI web site. As a follow-up to this report, EPRI is developing a CFSI Database; any country interested in a collaborative agreement is invited to use and contribute to the database information. Finally, it stresses the importance of the oversight of contractors, training to raise the awareness of the employees and the inspectors, and having a response plan for identified items

Utilizing Response Time Distributions for Item Selection in CAT

Science.gov (United States)

Fan, Zhewen; Wang, Chun; Chang, Hua-Hua; Douglas, Jeffrey

2012-01-01

Traditional methods for item selection in computerized adaptive testing only focus on item information without taking into consideration the time required to answer an item. As a result, some examinees may receive a set of items that take a very long time to finish, and information is not accrued as efficiently as possible. The authors propose two…

Item analysis and evaluation in the examinations in the faculty of ...

African Journals Online (AJOL)

2014-11-05

Nov 5, 2014 ... Key words: Classical test theory, item analysis, item difficulty, item discrimination, item response theory, reliability ... the probability of answering an item correctly or of attaining ..... A Monte Carlo comparison of item and person.

Why item parcels are (almost) never appropriate: two wrongs do not make a right--camouflaging misspecification with item parcels in CFA models.

Science.gov (United States)

Marsh, Herbert W; Lüdtke, Oliver; Nagengast, Benjamin; Morin, Alexandre J S; Von Davier, Matthias

2013-09-01

The present investigation has a dual focus: to evaluate problematic practice in the use of item parcels and to suggest exploratory structural equation models (ESEMs) as a viable alternative to the traditional independent clusters confirmatory factor analysis (ICM-CFA) model (with no cross-loadings, subsidiary factors, or correlated uniquenesses). Typically, it is ill-advised to (a) use item parcels when ICM-CFA models do not fit the data, and (b) retain ICM-CFA models when items cross-load on multiple factors. However, the combined use of (a) and (b) is widespread and often provides such misleadingly good fit indexes that applied researchers might believe that misspecification problems are resolved--that 2 wrongs really do make a right. Taking a pragmatist perspective, in 4 studies we demonstrate with responses to the Rosenberg Self-Esteem Inventory (Rosenberg, 1965), Big Five personality factors, and simulated data that even small cross-loadings seriously distort relations among ICM-CFA constructs or even decisions on the number of factors; although obvious in item-level analyses, this is camouflaged by the use of parcels. ESEMs provide a viable alternative to ICM-CFAs and a test for the appropriateness of parcels. The use of parcels with an ICM-CFA model is most justifiable when the fit of both ICM-CFA and ESEM models is acceptable and equally good, and when substantively important interpretations are similar. However, if the ESEM model fits the data better than the ICM-CFA model, then the use of parcels with an ICM-CFA model typically is ill-advised--particularly in studies that are also interested in scale development, latent means, and measurement invariance.

An NCME Instructional Module on Polytomous Item Response Theory Models

Science.gov (United States)

Penfield, Randall David

2014-01-01

A polytomous item is one for which the responses are scored according to three or more categories. Given the increasing use of polytomous items in assessment practices, item response theory (IRT) models specialized for polytomous items are becoming increasingly common. The purpose of this ITEMS module is to provide an accessible overview of…

LLWnotes - Volume 11, Number 4

International Nuclear Information System (INIS)

1996-05-01

This document is the May 1996 issue of LLWnotes. It contains articles and news items on the following topics: news items related to states and compacts; Low-Level Radioactive Waste (LLW) Forum activities; court rulings and calendars; US DOE testing at Ward Valley; US BLM contract with Lawrence Livermore National Laboratory; Mixed Waste Pilot Project Schedule; extension of US EPA's mixed waste enforcement moratorium; EPA Advisory Committee on research program operation; and decommissioning

LLWnotes - Volume 11, Number 4

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-05-01

This document is the May 1996 issue of LLWnotes. It contains articles and news items on the following topics: news items related to states and compacts; Low-Level Radioactive Waste (LLW) Forum activities; court rulings and calendars; US DOE testing at Ward Valley; US BLM contract with Lawrence Livermore National Laboratory; Mixed Waste Pilot Project Schedule; extension of US EPA`s mixed waste enforcement moratorium; EPA Advisory Committee on research program operation; and decommissioning.

Modeling the Severity of Drinking Consequences in First-Year College Women: An Item Response Theory Analysis of the Rutgers Alcohol Problem Index*

Science.gov (United States)

Cohn, Amy M.; Hagman, Brett T.; Graff, Fiona S.; Noel, Nora E.

2011-01-01

Objective: The present study examined the latent continuum of alcohol-related negative consequences among first-year college women using methods from item response theory and classical test theory. Method: Participants (N = 315) were college women in their freshman year who reported consuming any alcohol in the past 90 days and who completed assessments of alcohol consumption and alcohol-related negative consequences using the Rutgers Alcohol Problem Index. Results: Item response theory analyses showed poor model fit for five items identified in the Rutgers Alcohol Problem Index. Two-parameter item response theory logistic models were applied to the remaining 18 items to examine estimates of item difficulty (i.e., severity) and discrimination parameters. The item difficulty parameters ranged from 0.591 to 2.031, and the discrimination parameters ranged from 0.321 to 2.371. Classical test theory analyses indicated that the omission of the five misfit items did not significantly alter the psychometric properties of the construct. Conclusions: Findings suggest that those consequences that had greater severity and discrimination parameters may be used as screening items to identify female problem drinkers at risk for an alcohol use disorder. PMID:22051212

41 CFR 101-27.204 - Types of shelf-life items.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Types of shelf-life items...-Management of Shelf-Life Materials § 101-27.204 Types of shelf-life items. Shelf-life items are classified as nonextendable (Type I) and extendable (Type II). Type I items have a definite storage life after which the item...

Tailored Cloze: Improved with Classical Item Analysis Techniques.

Science.gov (United States)

Brown, James Dean

1988-01-01

The reliability and validity of a cloze procedure used as an English-as-a-second-language (ESL) test in China were improved by applying traditional item analysis and selection techniques. The 'best' test items were chosen on the basis of item facility and discrimination indices, and were administered as a 'tailored cloze.' 29 references listed.…

Corpus callosum thickness on mid-sagittal MRI as a marker of brain volume: a pilot study in children with HIV-related brain disease and controls

Energy Technology Data Exchange (ETDEWEB)

Andronikou, Savvas [University of the Witwatersrand, Department of Radiology, Faculty of Health Sciences, Cape Town (South Africa); Ackermann, Christelle [University of Stellenbosch, Department of Radiology, Stellenbosch (South Africa); Laughton, Barbara; Cotton, Mark [Stellenbosch University and Tygerberg Children' s Hospital, Children' s Infectious Diseases Research Unit, Stellenbosch (South Africa); Tomazos, Nicollette [University of Cape Town, Faculty of Commerce, Department of Management Studies, Cape Town (South Africa); Spottiswoode, Bruce [University of Cape Town, MRC/UCT Medical Imaging Research Unit, Department of Human Biology, Cape Town (South Africa); Mauff, Katya [University of Cape Town, Department of Statistical Sciences, Cape Town (South Africa); Pettifor, John M. [University of the Witwatersrand, MRC/Wits Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, Witwatersrand (South Africa)

2015-07-15

Corpus callosum thickness measurement on mid-sagittal MRI may be a surrogate marker of brain volume. This is important for evaluation of diseases causing brain volume gain or loss, such as HIV-related brain disease and HIV encephalopathy. To determine if thickness of the corpus callosum on mid-sagittal MRI is a surrogate marker of brain volume in children with HIV-related brain disease and in controls without HIV. A retrospective MRI analysis in children (<5 years old) with HIV-related brain disease and controls used a custom-developed semi-automated tool, which divided the midline corpus callosum and measured its thickness in multiple locations. Brain volume was determined using volumetric analysis. Overall corpus callosum thickness and thickness of segments of the corpus callosum were correlated with overall and segmented (grey and white matter) brain volume. Forty-four children (33 HIV-infected patients and 11 controls) were included. Significant correlations included overall corpus callosum (mean) and total brain volume (P = 0.05); prefrontal corpus callosum maximum with white matter volume (P = 0.02); premotor corpus callosum mean with total brain volume (P = 0.04) and white matter volume (P = 0.02), premotor corpus callosum maximum with white matter volume (P = 0.02) and sensory corpus callosum mean with total brain volume (P = 0.02). Corpus callosum thickness correlates with brain volume both in HIV-infected patients and controls. (orig.)

Corpus callosum thickness on mid-sagittal MRI as a marker of brain volume: a pilot study in children with HIV-related brain disease and controls

International Nuclear Information System (INIS)

Andronikou, Savvas; Ackermann, Christelle; Laughton, Barbara; Cotton, Mark; Tomazos, Nicollette; Spottiswoode, Bruce; Mauff, Katya; Pettifor, John M.

2015-01-01

Corpus callosum thickness measurement on mid-sagittal MRI may be a surrogate marker of brain volume. This is important for evaluation of diseases causing brain volume gain or loss, such as HIV-related brain disease and HIV encephalopathy. To determine if thickness of the corpus callosum on mid-sagittal MRI is a surrogate marker of brain volume in children with HIV-related brain disease and in controls without HIV. A retrospective MRI analysis in children (<5 years old) with HIV-related brain disease and controls used a custom-developed semi-automated tool, which divided the midline corpus callosum and measured its thickness in multiple locations. Brain volume was determined using volumetric analysis. Overall corpus callosum thickness and thickness of segments of the corpus callosum were correlated with overall and segmented (grey and white matter) brain volume. Forty-four children (33 HIV-infected patients and 11 controls) were included. Significant correlations included overall corpus callosum (mean) and total brain volume (P = 0.05); prefrontal corpus callosum maximum with white matter volume (P = 0.02); premotor corpus callosum mean with total brain volume (P = 0.04) and white matter volume (P = 0.02), premotor corpus callosum maximum with white matter volume (P = 0.02) and sensory corpus callosum mean with total brain volume (P = 0.02). Corpus callosum thickness correlates with brain volume both in HIV-infected patients and controls. (orig.)

Calibration of context-specific survey items to assess youth physical activity behaviour.

Science.gov (United States)

Saint-Maurice, Pedro F; Welk, Gregory J; Bartee, R Todd; Heelan, Kate

2017-05-01

This study tests calibration models to re-scale context-specific physical activity (PA) items to accelerometer-derived PA. A total of 195 4th-12th grades children wore an Actigraph monitor and completed the Physical Activity Questionnaire (PAQ) one week later. The relative time spent in moderate-to-vigorous PA (MVPA % ) obtained from the Actigraph at recess, PE, lunch, after-school, evening and weekend was matched with a respective item score obtained from the PAQ's. Item scores from 145 participants were calibrated against objective MVPA % using multiple linear regression with age, and sex as additional predictors. Predicted minutes of MVPA for school, out-of-school and total week were tested in the remaining sample (n = 50) using equivalence testing. The results showed that PAQ β-weights ranged from 0.06 (lunch) to 4.94 (PE) MVPA % (P PAQ and accelerometer MVPA at school and out-of-school ranged from -15.6 to +3.8 min and the PAQ was within 10-15% of accelerometer measured activity. This study demonstrated that context-specific items can be calibrated to predict minutes of MVPA in groups of youth during in- and out-of-school periods.

Effects of aging and divided attention on memory for items and their contexts.

Science.gov (United States)

Craik, Fergus I M; Luo, Lin; Sakuta, Yuiko

2010-12-01

It is commonly found that memory for context declines disproportionately with aging, arguably due to a general age-related deficit in associative memory processes. One possible mechanism for such deficits is an age-related reduction in available processing resources. In two experiments we compared the effects of aging to the effects of division of attention in younger adults on memory for items and context. Using a technique proposed by Craik (1989), linear functions relating memory performance for items and their contexts were derived for a Young Full Attention group, a Young Divided Attention group, and an Older Adult group. Results suggested that the Old group showed an additional deficit in associative memory that was not mimicked by divided attention. It is speculated that both divided attention and aging are associated with a loss of available processing resources that may reflect inefficient frontal lobe functioning, whereas the additional age-related decrement in associative memory may reflect inefficient processing in medial-temporal regions. (c) 2010 APA, all rights reserved).

Analysis test of understanding of vectors with the three-parameter logistic model of item response theory and item response curves technique

Directory of Open Access Journals (Sweden)

Suttida Rakkapao

2016-10-01

Full Text Available This study investigated the multiple-choice test of understanding of vectors (TUV, by applying item response theory (IRT. The difficulty, discriminatory, and guessing parameters of the TUV items were fit with the three-parameter logistic model of IRT, using the parscale program. The TUV ability is an ability parameter, here estimated assuming unidimensionality and local independence. Moreover, all distractors of the TUV were analyzed from item response curves (IRC that represent simplified IRT. Data were gathered on 2392 science and engineering freshmen, from three universities in Thailand. The results revealed IRT analysis to be useful in assessing the test since its item parameters are independent of the ability parameters. The IRT framework reveals item-level information, and indicates appropriate ability ranges for the test. Moreover, the IRC analysis can be used to assess the effectiveness of the test’s distractors. Both IRT and IRC approaches reveal test characteristics beyond those revealed by the classical analysis methods of tests. Test developers can apply these methods to diagnose and evaluate the features of items at various ability levels of test takers.

Analysis test of understanding of vectors with the three-parameter logistic model of item response theory and item response curves technique

Science.gov (United States)

Rakkapao, Suttida; Prasitpong, Singha; Arayathanitkul, Kwan

2016-12-01

This study investigated the multiple-choice test of understanding of vectors (TUV), by applying item response theory (IRT). The difficulty, discriminatory, and guessing parameters of the TUV items were fit with the three-parameter logistic model of IRT, using the parscale program. The TUV ability is an ability parameter, here estimated assuming unidimensionality and local independence. Moreover, all distractors of the TUV were analyzed from item response curves (IRC) that represent simplified IRT. Data were gathered on 2392 science and engineering freshmen, from three universities in Thailand. The results revealed IRT analysis to be useful in assessing the test since its item parameters are independent of the ability parameters. The IRT framework reveals item-level information, and indicates appropriate ability ranges for the test. Moreover, the IRC analysis can be used to assess the effectiveness of the test's distractors. Both IRT and IRC approaches reveal test characteristics beyond those revealed by the classical analysis methods of tests. Test developers can apply these methods to diagnose and evaluate the features of items at various ability levels of test takers.

Sharing medicine: the candidacy of medicines and other household items for sharing, Dominican Republic.

Directory of Open Access Journals (Sweden)

Michael N Dohn

Full Text Available People share medicines and problems can result from this behavior. Successful interventions to change sharing behavior will require understanding people's motives and purposes for sharing medicines. Better information about how medicines fit into the gifting and reciprocity system could be useful in designing interventions to modify medicine sharing behavior. However, it is uncertain how people situate medicines among other items that might be shared. This investigation is a descriptive study of how people sort medicines and other shareable items.This study in the Dominican Republic examined how a convenience sample (31 people sorted medicines and rated their shareability in relation to other common household items. We used non-metric multidimensional scaling to produce association maps in which the distances between items offer a visual representation of the collective opinion of the participants regarding the relationships among the items. In addition, from a pile sort constrained by four categories of whether sharing or loaning the item was acceptable (on a scale from not shareable to very shareable, we assessed the degree to which the participants rated the medicines as shareable compared to other items. Participants consistently grouped medicines together in all pile sort activities; yet, medicines were mixed with other items when rated by their candidacy to be shared. Compared to the other items, participants had more variability of opinion as to whether medicines should be shared.People think of medicines as a distinct group, suggesting that interventions might be designed to apply to medicines as a group. People's differing opinions as to whether it was appropriate to share medicines imply a degree of uncertainty or ambiguity that health promotion interventions might exploit to alter attitudes and behaviors. These findings have implications for the design of health promotion interventions to impact medicine sharing behavior.

An Item Bank to Measure Systems, Services, and Policies: Environmental Factors Affecting People With Disabilities.

Science.gov (United States)

Lai, Jin-Shei; Hammel, Joy; Jerousek, Sara; Goldsmith, Arielle; Miskovic, Ana; Baum, Carolyn; Wong, Alex W; Dashner, Jessica; Heinemann, Allen W

2016-12-01

To develop a measure of perceived systems, services, and policies facilitators (see Chapter 5 of the International Classification of Functioning, Disability and Health) for people with neurologic disabilities and to evaluate the effect of perceived systems, services, and policies facilitators on health-related quality of life. Qualitative approaches to develop and refine items. Confirmatory factor analysis including 1-factor confirmatory factor analysis and bifactor analysis to evaluate unidimensionality of items. Rasch analysis to identify misfitting items. Correlational and analysis of variance methods to evaluate construct validity. Community-dwelling individuals participated in telephone interviews or traveled to the academic medical centers where this research took place. Participants (N=571) had a diagnosis of spinal cord injury, stroke, or traumatic brain injury. They were 18 years or older and English speaking. Not applicable. An item bank to evaluate environmental access and support levels of services, systems, and policies for people with disabilities. We identified a general factor defined as "access and support levels of the services, systems, and policies at the level of community living" and 3 local factors defined as "health services," "community living," and "community resources." The systems, services, and policies measure correlated moderately with participation measures: Community Participation Indicators (CPI) - Involvement, CPI - Control over Participation, Quality of Life in Neurological Disorders - Ability to Participate, Quality of Life in Neurological Disorders - Satisfaction with Role Participation, Patient-Reported Outcomes Measurement Information System (PROMIS) Ability to Participate, PROMIS Satisfaction with Role Participation, and PROMIS Isolation. The measure of systems, services, and policies facilitators contains items pertaining to health services, community living, and community resources. Investigators and clinicians can measure

41 CFR 101-26.605 - Items other than petroleum products and electronic items available from the Defense Logistics...

Science.gov (United States)

2010-07-01

... petroleum products and electronic items available from the Defense Logistics Agency. 101-26.605 Section 101... available from the Defense Logistics Agency. Agencies required to use GSA supply sources should also use... Logistics Agency, the catalog will contain only those items in Federal supply classification classes which...

Extending item response theory to online homework

Directory of Open Access Journals (Sweden)

Gerd Kortemeyer

2014-05-01

Full Text Available Item response theory (IRT becomes an increasingly important tool when analyzing “big data” gathered from online educational venues. However, the mechanism was originally developed in traditional exam settings, and several of its assumptions are infringed upon when deployed in the online realm. For a large-enrollment physics course for scientists and engineers, the study compares outcomes from IRT analyses of exam and homework data, and then proceeds to investigate the effects of each confounding factor introduced in the online realm. It is found that IRT yields the correct trends for learner ability and meaningful item parameters, yet overall agreement with exam data is moderate. It is also found that learner ability and item discrimination is robust over a wide range with respect to model assumptions and introduced noise. Item difficulty is also robust, but over a narrower range.

Editorial Changes and Item Performance: Implications for Calibration and Pretesting

Directory of Open Access Journals (Sweden)

Heather Stoffel

2014-11-01

Full Text Available Previous research on the impact of text and formatting changes on test-item performance has produced mixed results. This matter is important because it is generally acknowledged that any change to an item requires that it be recalibrated. The present study investigated the effects of seven classes of stylistic changes on item difficulty, discrimination, and response time for a subset of 65 items that make up a standardized test for physician licensure completed by 31,918 examinees in 2012. One of two versions of each item (original or revised was randomly assigned to examinees such that each examinee saw only two experimental items, with each item being administered to approximately 480 examinees. The stylistic changes had little or no effect on item difficulty or discrimination; however, one class of edits -' changing an item from an open lead-in (incomplete statement to a closed lead-in (direct question -' did result in slightly longer response times. Data for nonnative speakers of English were analyzed separately with nearly identical results. These findings have implications for the conventional practice of repretesting (or recalibrating items that have been subjected to minor editorial changes.

Less Daily Computer Use is Related to Smaller Hippocampal Volumes in Cognitively Intact Elderly.

Science.gov (United States)

Silbert, Lisa C; Dodge, Hiroko H; Lahna, David; Promjunyakul, Nutta-On; Austin, Daniel; Mattek, Nora; Erten-Lyons, Deniz; Kaye, Jeffrey A

2016-01-01

Computer use is becoming a common activity in the daily life of older individuals and declines over time in those with mild cognitive impairment (MCI). The relationship between daily computer use (DCU) and imaging markers of neurodegeneration is unknown. The objective of this study was to examine the relationship between average DCU and volumetric markers of neurodegeneration on brain MRI. Cognitively intact volunteers enrolled in the Intelligent Systems for Assessing Aging Change study underwent MRI. Total in-home computer use per day was calculated using mouse movement detection and averaged over a one-month period surrounding the MRI. Spearman's rank order correlation (univariate analysis) and linear regression models (multivariate analysis) examined hippocampal, gray matter (GM), white matter hyperintensity (WMH), and ventricular cerebral spinal fluid (vCSF) volumes in relation to DCU. A voxel-based morphometry analysis identified relationships between regional GM density and DCU. Twenty-seven cognitively intact participants used their computer for 51.3 minutes per day on average. Less DCU was associated with smaller hippocampal volumes (r = 0.48, p = 0.01), but not total GM, WMH, or vCSF volumes. After adjusting for age, education, and gender, less DCU remained associated with smaller hippocampal volume (p = 0.01). Voxel-wise analysis demonstrated that less daily computer use was associated with decreased GM density in the bilateral hippocampi and temporal lobes. Less daily computer use is associated with smaller brain volume in regions that are integral to memory function and known to be involved early with Alzheimer's pathology and conversion to dementia. Continuous monitoring of daily computer use may detect signs of preclinical neurodegeneration in older individuals at risk for dementia.

On multidimensional item response theory -- a coordinate free approach

OpenAIRE

Antal, Tamás

2007-01-01

A coordinate system free definition of complex structure multidimensional item response theory (MIRT) for dichotomously scored items is presented. The point of view taken emphasizes the possibilities and subtleties of understanding MIRT as a multidimensional extension of the ``classical'' unidimensional item response theory models. The main theorem of the paper is that every monotonic MIRT model looks the same; they are all trivial extensions of univariate item response theory.

National soft science research task item-organization and implementation

International Nuclear Information System (INIS)

Zhang Yiming

2014-01-01

nuclear fusion energy research development road suitable to China's situation. This report has obtained the high praise from the domestic fusion experts. At present, this item is waiting for the acceptance check organized by the Ministry of Science and Technology. It is the first time for the Division to take on such a large-scale national level soft task item. It started a good beginning for the Division to further carry out related subject research tasks and knowledge services such as the comparative analyses of the related subjects and international attractive advanced subjects in the near future, train professional talents, as well as to provide information support of making scientific research further at SWIP. This paper discussed how to organize, implement and fulfil a large-scale strategic soft science task item based on the practice and experience of the completed soft science task item. (author)

Item response theory applied to factors affecting the patient journey towards hearing rehabilitation

Directory of Open Access Journals (Sweden)

Michelene Chenault

2016-11-01

Full Text Available To develop a tool for use in hearing screening and to evaluate the patient journey towards hearing rehabilitation, responses to the hearing aid rehabilitation questionnaire scales aid stigma, pressure, and aid unwanted addressing respectively hearing aid stigma, experienced pressure from others; perceived hearing aid benefit were evaluated with item response theory. The sample was comprised of 212 persons aged 55 years or more; 63 were hearing aid users, 64 with and 85 persons without hearing impairment according to guidelines for hearing aid reimbursement in the Netherlands. Bias was investigated relative to hearing aid use and hearing impairment within the differential test functioning framework. Items compromising model fit or demonstrating differential item functioning were dropped. The aid stigma scale was reduced from 6 to 4, the pressure scale from 7 to 4, and the aid unwanted scale from 5 to 4 items. This procedure resulted in bias-free scales ready for screening purposes and application to further understand the help-seeking process of the hearing impaired.

Examining the Psychometric Quality of Multiple-Choice Assessment Items using Mokken Scale Analysis.

Science.gov (United States)

Wind, Stefanie A

The concept of invariant measurement is typically associated with Rasch measurement theory (Engelhard, 2013). Concerned with the appropriateness of the parametric transformation upon which the Rasch model is based, Mokken (1971) proposed a nonparametric procedure for evaluating the quality of social science measurement that is theoretically and empirically related to the Rasch model. Mokken's nonparametric procedure can be used to evaluate the quality of dichotomous and polytomous items in terms of the requirements for invariant measurement. Despite these potential benefits, the use of Mokken scaling to examine the properties of multiple-choice (MC) items in education has not yet been fully explored. A nonparametric approach to evaluating MC items is promising in that this approach facilitates the evaluation of assessments in terms of invariant measurement without imposing potentially inappropriate transformations. Using Rasch-based indices of measurement quality as a frame of reference, data from an eighth-grade physical science assessment are used to illustrate and explore Mokken-based techniques for evaluating the quality of MC items. Implications for research and practice are discussed.

Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

DEFF Research Database (Denmark)

Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas

2010-01-01

During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading...... of heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank-Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males...... from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature 1 degrees C), and during whole...

Development of an item bank for food parenting practices based on published instruments and reports from Canadian and US parents.

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O'Connor, Teresia M; Pham, Truc; Watts, Allison W; Tu, Andrew W; Hughes, Sheryl O; Beauchamp, Mark R; Baranowski, Tom; Mâsse, Louise C

2016-08-01

Research to understand how parents influence their children's dietary intake and eating behaviors has expanded in the past decades and a growing number of instruments are available to assess food parenting practices. Unfortunately, there is no consensus on how constructs should be defined or operationalized, making comparison of results across studies difficult. The aim of this study was to develop a food parenting practice item bank with items from published scales and supplement with parenting practices that parents report using. Items from published scales were identified from two published systematic reviews along with an additional systematic review conducted for this study. Parents (n = 135) with children 5-12 years old from the US and Canada, stratified to represent the demographic distribution of each country, were recruited to participate in an online semi-qualitative survey on food parenting. Published items and parent responses were coded using the same framework to reduce the number of items into representative concepts using a binning and winnowing process. The literature contributed 1392 items and parents contributed 1985 items, which were reduced to 262 different food parenting concepts (26% exclusive from literature, 12% exclusive from parents, and 62% represented in both). Food parenting practices related to 'Structure of Food Environment' and 'Behavioral and Educational' were emphasized more by parent responses, while practices related to 'Consistency of Feeding Environment' and 'Emotional Regulation' were more represented among published items. The resulting food parenting item bank should next be calibrated with item response modeling for scientists to use in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Verification of Differential Item Functioning (DIF) Status of West ...

African Journals Online (AJOL)

This study investigated test item bias and Differential Item Functioning (DIF) of West African ... items in chemistry function differentially with respect to gender and location. In Aba education zone of Abia, 50 secondary schools were purposively ...

Mixture Item Response Theory-MIMIC Model: Simultaneous Estimation of Differential Item Functioning for Manifest Groups and Latent Classes

Science.gov (United States)

Bilir, Mustafa Kuzey

2009-01-01

This study uses a new psychometric model (mixture item response theory-MIMIC model) that simultaneously estimates differential item functioning (DIF) across manifest groups and latent classes. Current DIF detection methods investigate DIF from only one side, either across manifest groups (e.g., gender, ethnicity, etc.), or across latent classes…

Guidelines for the technical evaluation of replacement items in nuclear power plants (NCIG-11)

International Nuclear Information System (INIS)

Craig, W.E.; Fakhar, A.A.; Shulman, M.N.

1989-12-01

This document presents guidelines and supporting information for the technical evaluation of replacement items in nuclear power plants. These guidelines contain six major sections which provide the practical knowledge and a programmatic approach to determine the technical and quality requirements necessary to generate purchase documents to procure the proper replacement items. The technical evaluation methodology includes the following steps. (1) Identification of the need for a technical evaluation. (2) Component/part functional classification procedures. (3) Performance of a Failure Modes and Effects Analysis. (4) Selection of Critical Characteristics for Design Determination. (5) Performance of a ''Like-For-Like'' or ''Alternate'' item Evaluation. (6) Preparation of the Technical and Quality Requirements Specification. Work on this document was initiated in response to the increased emphasis by the utilities owning nuclear power plants and nuclear industry on procurement of replacement items for use in safety related applications at nuclear power plants. 20 refs., 9 figs., 14 tabs

Lung volumes related to physical activity, physical fitness, aerobic capacity and body mass index in students

Directory of Open Access Journals (Sweden)

Mihailova A.

2016-01-01

Reduced lung volumes were associated with lower aerobic fitness, lower physical fitness and lower amount of weekly physical activity. Healthier body mass index was associated with higher aerobic fitness (relative VO2max in both female and male.

Understanding and quantifying cognitive complexity level in mathematical problem solving items

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SUSAN E. EMBRETSON

2008-09-01

Full Text Available The linear logistic test model (LLTM; Fischer, 1973 has been applied to a wide variety of new tests. When the LLTM application involves item complexity variables that are both theoretically interesting and empirically supported, several advantages can result. These advantages include elaborating construct validity at the item level, defining variables for test design, predicting parameters of new items, item banking by sources of complexity and providing a basis for item design and item generation. However, despite the many advantages of applying LLTM to test items, it has been applied less often to understand the sources of complexity for large-scale operational test items. Instead, previously calibrated item parameters are modeled using regression techniques because raw item response data often cannot be made available. In the current study, both LLTM and regression modeling are applied to mathematical problem solving items from a widely used test. The findings from the two methods are compared and contrasted for their implications for continued development of ability and achievement tests based on mathematical problem solving items.

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.

Improved Approximation Algorithms for Item Pricing with Bounded Degree and Valuation

Science.gov (United States)

Hamane, Ryoso; Itoh, Toshiya

When a store sells items to customers, the store wishes to decide the prices of the items to maximize its profit. If the store sells the items with low (resp. high) prices, the customers buy more (resp. less) items, which provides less profit to the store. It would be hard for the store to decide the prices of items. Assume that a store has a set V of n items and there is a set C of m customers who wish to buy those items. The goal of the store is to decide the price of each item to maximize its profit. We refer to this maximization problem as an item pricing problem. We classify the item pricing problems according to how many items the store can sell or how the customers valuate the items. If the store can sell every item i with unlimited (resp. limited) amount, we refer to this as unlimited supply (resp. limited supply). We say that the item pricing problem is single-minded if each customer j∈C wishes to buy a set ej⊆V of items and assigns valuation w(ej)≥0. For the single-minded item pricing problems (in unlimited supply), Balcan and Blum regarded them as weighted k-hypergraphs and gave several approximation algorithms. In this paper, we focus on the (pseudo) degree of k-hypergraphs and the valuation ratio, i. e., the ratio between the smallest and the largest valuations. Then for the single-minded item pricing problems (in unlimited supply), we show improved approximation algorithms (for k-hypergraphs, general graphs, bipartite graphs, etc.) with respect to the maximum (pseudo) degree and the valuation ratio.

Development and psychometric characteristics of the SCI-QOL Ability to Participate and Satisfaction with Social Roles and Activities item banks and short forms.

Science.gov (United States)

Heinemann, Allen W; Kisala, Pamela A; Hahn, Elizabeth A; Tulsky, David S

2015-05-01

To develop a spinal cord injury (SCI)-focused version of PROMIS and Neuro-QOL social domain item banks; evaluate the psychometric properties of items developed for adults with SCI; and report information to facilitate clinical and research use. We used a mixed-methods design to develop and evaluate Ability to Participate in Social Roles and Activities and Satisfaction with Social Roles and Activities items. Focus groups helped define the constructs; cognitive interviews helped revise items; and confirmatory factor analysis and item response theory methods helped calibrate item banks and evaluate differential item functioning related to demographic and injury characteristics. Five SCI Model System sites and one Veterans Administration medical center. The calibration sample consisted of 641 individuals; a reliability sample consisted of 245 individuals residing in the community. A subset of 27 Ability to Participate and 35 Satisfaction items demonstrated good measurement properties and negligible differential item functioning related to demographic and injury characteristics. The SCI-specific measures correlate strongly with the PROMIS and Neuro-QOL versions. Ten item short forms correlate >0.96 with the full banks. Variable-length CATs with a minimum of 4 items, variable-length CATs with a minimum of 8 items, fixed-length CATs of 10 items, and the 10-item short forms demonstrate construct coverage and measurement error that is comparable to the full item bank. The Ability to Participate and Satisfaction with Social Roles and Activities CATs and short forms demonstrate excellent psychometric properties and are suitable for clinical and research applications.

Item-level factor analysis of the Self-Efficacy Scale.