Recently, several authors have introduced and discussed the advantage of the use of item response theory models (IRT) to construct personality scales and to explore the structure of personality data sets. For example, Waller, Tellegen, McDonald, and Lykken (1996) contrasted the use of IRT to principal factor analysis and Reise and Waller (in press) discussed the choice of an IRT model to analyz...

BACKGROUND AND OBJECTIVE To develop computerized adaptive tests (CATs) designed to assess lower extremity functional status (FS) in people with lower extremity impairments using items from the Lower Extremity Functional Scale and compare discriminant validity of FS measures generated using all items analyzed with a rating scale Item Response Theory model (theta(IRT)) and measures generated usin...

PURPOSE The present work describes how vocabulary ability as assessed by 3 different forms of the Peabody Picture Vocabulary Test (PPVT; Dunn & Dunn, 1997) can be placed on a common latent metric through item response theory (IRT) modeling, by which valid comparisons of ability between samples or over time can then be made. METHOD Responses from 2,625 cases in a longitudinal study of 697 pers...

Differential item functioning (DIF), as an assessment tool, has been widely used in quantitative psychology, educational measurement, business management, and insurance and healthcare industries. The purpose of DIF analyses is to detect response differences of items in questionnaires, rating scales, or tests across different subgroups (e.g., gender), while controlling for ability level. There a...

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-worl...

CONTEXT The multiple mini-interview (MMI) was initially designed to test non-cognitive characteristics related to professionalism in entry-level students. However, it may be testing cognitive reasoning skills. Candidates to medical and dental schools come from diverse backgrounds and it is important for the validity and fairness of the MMI that these background factors do not impact on their sc...

BACKGROUND The following minimal set of valid health domains for tracking the health of both clinical and general populations has recently been proposed: 1) energy and drive functions, 2) emotional functions, 3) sensation of pain, 4) carrying out daily routine, 5) walking and moving around, and 6) remunerative employment. This study investigates whether these domains can be integrated into a so...

This paper applies the techniques of Item Response Theory (IRT) to data from the Statistics Concept Inventory (SCI). Based on results from the Fall 2005 post-test (n = 422 students), the analyses of IRT are compared with those of Classical Test Theory (CTT). The concepts are extended to discussions of other applications, such as computerized adaptive testing and Likertscale items which may be o...

BACKGROUND The Center for Epidemiologic Studies Depression Scale (CES-D) is a measure of depressive symptomatology which is widely used internationally. Though previous attempts were made to shorten the CES-D scale, few have attempted to develop a Computerized Adaptive Test (CAT) version for the CES-D. OBJECTIVE The aim of this study was to provide evidence on the efficiency and accuracy of t...

BACKGROUND Although item response theory (IRT) appears to be increasingly used within health care research in general, a comprehensive overview of the frequency and characteristics of IRT analyses within the rheumatic field is lacking. An overview of the use and application of IRT in rheumatology to date may give insight into future research directions and highlight new possibilities for the im...