The use and interpretation of educational and psychological test scores are paramount to individual outcomes and opportunities. Methods for detecting differential item functioning (DIF) are imperative for item analysis when developing and revising assessments, particularly as it pertains to fairness across populations, languages, and cultures. We…

The purpose of this ITEMS module is to provide an introduction to differential item functioning (DIF) analysis using mixture item response models. The mixture item response models for DIF analysis involve comparing item profiles across latent groups, instead of manifest groups. First, an overview of DIF analysis based on latent groups, called…

Historically, research focusing on rater characteristics and rating contexts that enable the assignment of accurate ratings and research focusing on statistical indicators of accurate ratings has been conducted by separate communities of researchers. This study demonstrates how existing latent trait modeling procedures can identify groups of…

In this paper I describe and illustrate the Roussos-Stout (1996) multidimensionality-based DIF analysis paradigm, with emphasis on its implication for the selection of a matching and studied subtest for DIF analyses. Standard DIF practice encourages an exploratory search for matching subtest items based on purely statistical criteria, such as a…