Randy Penfield, Professor and Chair of ERM, recently co-authored a paper with Dr. Corinne Huggins of the University of Florida that received the Distinguished Paper Award from the Florida Educational Research Association (FERA). The paper, entitled The Relationship between DIF Location and Conditional Equating Dependence Issues, explores the manner in which differential item functioning (DIF) effects of specific items contained in anchor tests lead to violations of equating invariance. The results of the paper shed light on the potential impact that DIF in anchor test items can have on the validity of equated scores when a single equating is applied equally to different demographic groups. Because the presence of DIF often reflects the presence of a biasing factor in the test, the paper addresses an important topic related to equity in testing.
The results of the paper were obtained using a large simulation study implemented using the framework of item response theory and a broad range of educational measurement techniques including item parameter estimation, test equating, and DIF effect estimation. Advanced training in these areas is provided by ERM’s graduate programs.