BACKGROUND Performance on psychometric tests is key to diagnosis and monitoring treatment of dementia. Results are often reported as a total score, but there is additional information in individual items of tests which vary in their difficulty and discriminatory value. Item difficulty refers to an ability level at which the probability of responding correctly is 50%. Discrimination is an index ...

Item response theory (IRT) is an important method of assessing the validity of measurement scales that is underutilized in the field of psychiatry. IRT describes the relationship between a latent trait (e.g., the construct that the scale proposes to assess), the properties of the items in the scale, and respondents' answers to the individual items. This paper introduces the basic premise, assum...

Due to the computerization of assessment tests, the use of Item Response Theory (IRT) has become commonplace for educational assessment development, evaluation, and refinement. When used appropriately by a Learning Management System (LMS), IRT can improve the assessment quality, increase the efficiency of the testing process, and provide in-depth descriptions of item and test properties. This p...

Item response theory (IRT) models emerged to solve practical testing problems in large-scale cognitive achievement and aptitude assessment. Within the last decade, an explosion of IRT applications have occurred in the non-cognitive domain. In this report, I highlight the development, implementation, and results of a single project: Patient Reported Outcomes Measurement Information Systems (PROM...

An approach called generalizability in item response modeling (GIRM) is introduced in this article. The GIRM approach essentially incorporates the sampling model of generalizability theory (GT) into the scaling model of item response theory (IRT) by making distributional assumptions about the relevant measurement facets. By specifying a random effects measurement model, and taking advantage of ...

As of December 2011, 13 states have adopted an in-state resident tuition (IRT) policy that provides in-state tuition to undocumented immigrants and several other states are considering similar legislation. While previous research focuses on how IRT policies affect college entry and attainment, this study examines the effect these policies have on high school dropout behavior. Using the Current ...

This article provides analytic evaluations of population true-score measures for binary items given their item response theory (IRT) calibration. Under the assumption of normal trait distribution, the expected values of marginalized true scores, error variance, true score variance, and reliability for norm-referenced and criterion-referenced interpretations are presented as a function of the it...

BACKGROUND/AIMS An item response theory (IRT)-based scoring approach to the Clinical Dementia Rating Scale (CDR) can account for the pattern of scores across the CDR items (domains) and their differential abilities to indicate dementia severity. In doing so, an IRT-based approach can provide greater precision than other CDR scoring algorithms. However, neither a good set of item parameters nor ...

Benefits of physical activity for those with arthritis are clear, yet physical activity is difficult to initiate and maintain. Self-efficacy is a key modifiable psychosocial determinant of physical activity. This study examined two scales for self-efficacy for exercise behavior (SEEB) to identify their strengths and weaknesses using item response theory (IRT) from community-based randomized con...