Using Generalized Mantel-Haenszel Statistics to Assess DIF Among Multiple Groups

In spite of the growing interest in cross-cultural research and assessment, there is little research on statistical procedures that can be used to simultaneously assess the differential item functioning (DIF) across multiple groups. The chief objective of this work is to show a unified framework for the analysis of DIF in multiple groups using one of the most popular methodologies for DIF assessment: the Mantel-Haenszel (MH) methods. The MH statistics proposed to date with this purpose only permitted analysis of the DIF for dichotomous items. In contrast, the statistics presented here permit, through a single significance test, simultaneous evaluation of the DIF in several groups, being applicable to both dichotomous and polytomous items. Specific software to detect DIF using this methodology is available free of charge.