A Comparison of Three Nonparametric Methods for Detecting Differential Item Functioning in Polytomous Items

• In Event: 52.083 - Roundtable Session 19
  In Roundtable Session: 52.083-19 - Advances in Differential Item Functioning Research

Abstract

The purpose of this study is to provide a resource for the Type 1 error rate and power of the Mantel, Standardized Mean Difference, and Liu-Agresti estimator of the cumulative common log-odds ratio approaches for detecting differential item functioning (DIF) in polytomous items. A simulation study was employed in which polytomous data were generated using the Graded Response Model (GRM; Samejima, 1969). The DIF detection methods were examined under five crossed conditions: (1) number of response categories (3-,4-, and 5-), (2) magnitude of DIF (small and large), (3) samples where the size of the reference and focal groups were equivalent, (4) samples where the reference to focal group ratio was 4:1, and (5) under constant pervasive or constant nonpervasive DIF.

Author

• Elizabeth Adele Patton, University of North Carolina - Greensboro