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 estimat...

Item response theory (IRT) models are a class of generalized mixed effect (GME) models used by psychometricians to describe the response behavior of individuals to a set of categorically scored items. The typical assumptions of IRT are Unidimensionality (U) of the random effect; Conditional (or Local) Independence (CI), the item responses are independent given the random effect; andMonotonicity...

Parameters of the two-parameter logistic model are generally estimated via the expectation-maximization algorithm, which improves initial values for all parameters iteratively until convergence is reached. Effects of initial values are rarely discussed in item response theory (IRT), but initial values were recently found to affect item parameters when estimating the latent distribution with ful...

BACKGROUND impairment of functional abilities represents a crucial component of dementia diagnosis. Current functional measures rely on the traditional aggregate method of summing raw scores. While this summary score provides a quick representation of a person's ability, it disregards useful information on the item level. OBJECTIVE to use item response theory (IRT) methods to increase the int...

Item response theory (IRT) is a modeling approach that links responses to test items with underlying latent constructs through formalized statistical models. This article focuses on how IRT can be used advance science and practice in organizations. We describe established applications of as scale development tool new research testing enables organizational researchers improve their understandin...

BACKGROUND Investigations using classical test theory support the psychometric properties of the original version of the Multiple Sclerosis Impact Scale (MSIS-29v1), a disease-specific measure of multiple sclerosis (MS) impact (physical and psychological subscales). Later, assessments of the MSIS-29v1 in an MS community-based sample using Rasch analysis led to revisions of the instrument's resp...

This study aimed to test the quality of item analysis in Indonesian IST 2000R using Item Response Theory (IRT) method and participants comprising 1780 students aged 16-20. IRT 3PL DIF examination showed that had good quality, with an improvement 70. The discriminatory power parameter (ɑ) verbal category items was high. Furthermore, difficulty level (b) indicated more than 50% on are average cat...

Observed associations between depression following myocardial infarction (MI) and adverse cardiac outcomes could be overestimated due to patients' tendency to over report somatic depressive symptoms. This study was aimed to investigate this issue with modern psychometrics, using item response theory (IRT) and person-fit statistics to investigate if the Beck Depression Inventory (BDI) measures d...

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...