An ANOVA-Like Rasch Analysis of Differential Item Functioning.

The conventional two-group differential item functioning (DIF) analysis is extended to an analysis of variance-like (ANOVA-like) DIF analysis where multiple factors with multiple groups are compared simultaneously. Moreover, DIF is treated as a parameter to be estimated rather than simply a sign to be detected. This proposed approach allows the investigation of the effects of DIF on items more thoroughly. Results of simulation studies show that the parameters of the proposed models were recovered very well. A real data set with 10 dichotomous items was analyzed. Implications and applications are discussed. (Contains 4 tables, 2 figures, and 10 references.) (Author/SLD)