Understanding Differential Item Functioning in Test Accommodation

• In Event: 51.078 - MTCC Roundtable Session 21
  In Roundtable Session: 51.078-12 - Inclusion and Accommodation in Educational Assessment SIG Roundtable

Abstract

In educational assessments, accommodations have been widely used to maintain fairness of the tests. DIF analyses have been used to examine effects of accommodations for students with disabilities during testing. Mixture models have also been used to help understand potential causes of the DIF items. The purpose of this study was to examine the role of model selection when conducting a mixture model analysis to understand the possible causes of DIF for an assessment using accommodations for students with disabilities. The 1PL, 2PL and 3PL IRT models were applied to a set of large-scale assessment data. The results were compared across the three IRT models to determine if model selection plays a role in understanding the observed DIF.

Authors

• Yu Meng, Inteleos

• Min Zhu, American Nurses Credentialing Center