Differential Item Functioning Detection and Effect Size: A Comparison between Logistic Regression and Mantel-Haenszel Procedures

This article compares several procedures in their efficacy for detecting differential item functioning (DIF): logistic regression analysis, the Mantel-Haenszel (MH) procedure, and the modified Mantel-Haenszel procedure by Mazor, Clauser, and Hambleton. It also compares the effect size measures that these procedures provide. In this study, different conditions of item parameters (difficulty and discrimination) and DIF magnitude were manipulated. Furthermore, both uniform and nonuniform DIF conditions were simulated. Results suggest that logistic regression analysis generally detected more items with DIF than the standard MH procedure and the modified MH procedure for symmetrical nonuniform DIF. The DIF effect size measures based on logistic regression, however, appeared to be insensitive to the specified DIF conditions.