This study examined how much improvement was attainable with respect to accuracy of differential item functioning (DIF) measures and DIF detection rates in the Mantel-Haenszel procedure when employing focal and reference groups with notably unbalanced sample sizes where the focal group has a fixed small sample which does not satisfy the minimum…

U.S. state educational testing programs administer tests to track student progress and hold schools accountable for educational outcomes. Methods from item response theory, especially Rasch models, are usually used to equate different forms of a test. The most popular method for estimating Rasch models yields inconsistent estimates and relies on…