Using Statistical Procedures to Identify Differentially Functioning Test Items

TLDR: The Mantel-Haenszel statistic, logistic regression, SIBTES'r, the Standardization procedure, and various IRT-based approaches are presented, and the relative strengths and weaknesses of the method are highlighted, and guidance is provided for interpretation of the resulting statistical indices.

Abstract: This module is intended to prepare the reader to use statistical proce­ dures to detect differentially functioning test items. 7b provide back­ ground, differential item functioning (DIF) is distinguished from item and test bias, and the importance of DIF screening within the overall test development process is discussed. The Mantel-Haenszel statistic, logistic regression, SIBTES'r, the Standardization procedure, and various IRT-based approaches are presented. For each of these proce­ dures, the theoretical framework is presented, the relative strengths and weaknesses of the method are highlighted, and guidance is pro­ vided for interpretation of the resulting statistical indices. Numerous technical decisions are required in order for the practitioner to appro­ priately implement these procedures. These decisions are discussed in some detail, as are the policy decisions necessary to implement an op­ erational DIF detection program. The module also includes an anno­ tated bibliography and a self-test.