An Approach for Categorizing DIF in Polytomous Items |
| |
| Authors: | Randall D Penfield |
| |
| Institution: | 1. Department of Educational and Psychological Studies , University of Miami , penfield@miami.edu |
| |
| Abstract: | A widely used approach for categorizing the level of differential item functioning (DIF) in dichotomous items is the scheme proposed by Educational Testing Service (ETS) based on a transformation of the Mantel-Haeszel common odds ratio. In this article two classification schemes for DIF in polytomous items (referred to as the P1 and P2 schemes) are proposed that parallel the criteria set forth in the ETS scheme for dichotomous items. The theoretical equivalence of the P1 and P2 schemes to the ETS scheme is described, and the results of a simulation study conducted to examine the empirical equivalence of the P1 and P2 schemes to the ETS scheme are presented. |
| |
| Keywords: | |
|
|
