02517nas a2200265   4500008004100000020004100041245013200082210006900214250001500283260000800298300001100306490000700317520154000324653003101864653003701895653003301932653002401965653001101989653002402000653002702024653003302051653003002084100001602114856012102130       2006                        eng d  a0025-7079 (Print)0025-7079 (Linking)00aOverview of quantitative measurement methods. Equivalence, invariance, and differential item functioning in health applications0 aOverview of quantitative measurement methods Equivalence invaria  a2006/10/25  cNov  aS39-490 v443 aBACKGROUND: Reviewed in this article are issues relating to the study of invariance and differential item functioning (DIF). The aim of factor analyses and DIF, in the context of invariance testing, is the examination of group differences in item response conditional on an estimate of disability. Discussed are parameters and statistics that are not invariant and cannot be compared validly in crosscultural studies with varying distributions of disability in contrast to those that can be compared (if the model assumptions are met) because they are produced by models such as linear and nonlinear regression. OBJECTIVES: The purpose of this overview is to provide an integrated approach to the quantitative methods used in this special issue to examine measurement equivalence. The methods include classical test theory (CTT), factor analytic, and parametric and nonparametric approaches to DIF detection. Also included in the quantitative section is a discussion of item banking and computerized adaptive testing (CAT). METHODS: Factorial invariance and the articles discussing this topic are introduced. A brief overview of the DIF methods presented in the quantitative section of the special issue is provided together with a discussion of ways in which DIF analyses and examination of invariance using factor models may be complementary. CONCLUSIONS: Although factor analytic and DIF detection methods share features, they provide unique information and can be viewed as complementary in informing about measurement equivalence.10a*Cross-Cultural Comparison10aData Interpretation, Statistical10aFactor Analysis, Statistical10aGuidelines as Topic10aHumans10aModels, Statistical10aPsychometrics/*methods10aStatistics as Topic/*methods10aStatistics, Nonparametric1 aTeresi, J A  uhttp://mail.iacat.org/content/overview-quantitative-measurement-methods-equivalence-invariance-and-differential-item02655nas a2200385   4500008004100000245014400041210006900185300001200254490000700266520138100273653002101654653003301675653002901708653001501737653001001752653000901762653002201771653002601793653003301819653002501852653001901877653001001896653002501906653001601931653002401947653002601971653002701997653003202024653001302056653002802069100001702097700001602114700001402130856012502144       2003                        eng d00aCalibration of an item pool for assessing the burden of headaches: an application of item response theory to the Headache Impact Test (HIT)0 aCalibration of an item pool for assessing the burden of headache  a913-9330 v123 aBACKGROUND: Measurement of headache impact is important in clinical trials, case detection, and the clinical monitoring of patients. Computerized adaptive testing (CAT) of headache impact has potential advantages over traditional fixed-length tests in terms of precision, relevance, real-time quality control and flexibility. OBJECTIVE: To develop an item pool that can be used for a computerized adaptive test of headache impact. METHODS: We analyzed responses to four well-known tests of headache impact from a population-based sample of recent headache sufferers (n = 1016). We used confirmatory factor analysis for categorical data and analyses based on item response theory (IRT). RESULTS: In factor analyses, we found very high correlations between the factors hypothesized by the original test constructers, both within and between the original questionnaires. These results suggest that a single score of headache impact is sufficient. We established a pool of 47 items which fitted the generalized partial credit IRT model. By simulating a computerized adaptive health test we showed that an adaptive test of only five items had a very high concordance with the score based on all items and that different worst-case item selection scenarios did not lead to bias. CONCLUSION: We have established a headache impact item pool that can be used in CAT of headache impact.10a*Cost of Illness10a*Decision Support Techniques10a*Sickness Impact Profile10aAdolescent10aAdult10aAged10aComparative Study10aDisability Evaluation10aFactor Analysis, Statistical10aHeadache/*psychology10aHealth Surveys10aHuman10aLongitudinal Studies10aMiddle Aged10aMigraine/psychology10aModels, Psychological10aPsychometrics/*methods10aQuality of Life/*psychology10aSoftware10aSupport, Non-U.S. Gov't1 aBjorner, J B1 aKosinski, M1 aWare, Jr.  uhttp://mail.iacat.org/content/calibration-item-pool-assessing-burden-headaches-application-item-response-theory-headache02156nas a2200277   4500008004100000020002200041245009600063210006900159250001500228260000800243300001100251490000700262520122800269653001601497653003901513653003701552653001101589653003301600653002501633653002701658653003101685100001701716700001601733700001701749856011201766       1999                        eng d  a1040-2446 (Print)00aEvaluating the usefulness of computerized adaptive testing for medical in-course assessment0 aEvaluating the usefulness of computerized adaptive testing for m  a1999/10/28  cOct  a1125-80 v743 aPURPOSE: This study investigated the feasibility of converting an existing computer-administered, in-course internal medicine test to an adaptive format. METHOD: A 200-item internal medicine extended matching test was used for this research. Parameters were estimated with commercially available software with responses from 621 examinees. A specially developed simulation program was used to retrospectively estimate the efficiency of the computer-adaptive exam format. RESULTS: It was found that the average test length could be shortened by almost half with measurement precision approximately equal to that of the full 200-item paper-and-pencil test. However, computer-adaptive testing with this item bank provided little advantage for examinees at the upper end of the ability continuum. An examination of classical item statistics and IRT item statistics suggested that adding more difficult items might extend the advantage to this group of examinees. CONCLUSIONS: Medical item banks presently used for incourse assessment might be advantageously employed in adaptive testing. However, it is important to evaluate the match between the items and the measurement objective of the test before implementing this format.10a*Automation10a*Education, Medical, Undergraduate10aEducational Measurement/*methods10aHumans10aInternal Medicine/*education10aLikelihood Functions10aPsychometrics/*methods10aReproducibility of Results1 aKreiter, C D1 aFerguson, K1 aGruppen, L D  uhttp://mail.iacat.org/content/evaluating-usefulness-computerized-adaptive-testing-medical-course-assessment01754nas a2200217   4500008004100000245015600041210006900197300001100266490000600277520090700283653004001190653002201230653002401252653002301276653003701299653001001336653002401346653002701370100001801397856012101415       1998                        eng d00aThe effect of item pool restriction on the precision of ability measurement for a Rasch-based CAT: comparisons to traditional fixed length examinations0 aeffect of item pool restriction on the precision of ability meas  a97-1220 v23 aThis paper describes a method for examining the precision of a computerized adaptive test with a limited item pool. Standard errors of measurement ascertained in the testing of simulees with a CAT using a restricted pool were compared to the results obtained in a live paper-and-pencil achievement testing of 4494 nursing students on four versions of an examination of calculations of drug administration. CAT measures of precision were considered when the simulated examine pools were uniform and normal. Precision indices were also considered in terms of the number of CAT items required to reach the precision of the traditional tests. Results suggest that regardless of the size of the item pool, CAT provides greater precision in measurement with a smaller number of items administered even when the choice of items is limited but fails to achieve equiprecision along the entire ability continuum.10a*Decision Making, Computer-Assisted10aComparative Study10aComputer Simulation10aEducation, Nursing10aEducational Measurement/*methods10aHuman10aModels, Statistical10aPsychometrics/*methods1 aHalkitis, P N  uhttp://mail.iacat.org/content/effect-item-pool-restriction-precision-ability-measurement-rasch-based-cat-comparisons02399nas a2200253   4500008004100000020002200041245012400063210006900187250001500256260000800271300001200279490000600291520152400297653001901821653003001840653002101870653003301891653002401924653001101948653002701959100001701986700001502003856012702018       1997                        eng d  a0962-9343 (Print)00aHealth status assessment for the twenty-first century: item response theory, item banking and computer adaptive testing0 aHealth status assessment for the twentyfirst century item respon  a1997/08/01  cAug  a595-6000 v63 aHealth status assessment is frequently used to evaluate the combined impact of human immunodeficiency virus (HIV) disease and its treatment on functioning and well-being from the patient's perspective. No single health status measure can efficiently cover the range of problems in functioning and well-being experienced across HIV disease stages. Item response theory (IRT), item banking and computer adaptive testing (CAT) provide a solution to measuring health-related quality of life (HRQoL) across different stages of HIV disease. IRT allows us to examine the response characteristics of individual items and the relationship between responses to individual items and the responses to each other item in a domain. With information on the response characteristics of a large number of items covering a HRQoL domain (e.g. physical function, and psychological well-being), and information on the interrelationships between all pairs of these items and the total scale, we can construct more efficient scales. Item banks consist of large sets of questions representing various levels of a HRQoL domain that can be used to develop brief, efficient scales for measuring the domain. CAT is the application of IRT and item banks to the tailored assessment of HRQoL domains specific to individual patients. Given the results of IRT analyses and computer-assisted test administration, more efficient and brief scales can be used to measure multiple domains of HRQoL for clinical trials and longitudinal observational studies.10a*Health Status10a*HIV Infections/diagnosis10a*Quality of Life10aDiagnosis, Computer-Assisted10aDisease Progression10aHumans10aPsychometrics/*methods1 aRevicki, D A1 aCella, D F  uhttp://mail.iacat.org/content/health-status-assessment-twenty-first-century-item-response-theory-item-banking-and-computer