Identifying Possible Sources of Differential Functioning Using Differential Bundle Functioning With Polytomously Scored Data

Oshima, Raju, Flowers, and Slinde (1998) Oshima, T. C., Raju, N. S., Flowers, C. P. and Slinde, J. A. 1998. Differential bundle functioning using the DFIT framework: Procedures for identifying possible sources of differential functioning. Applied Measurement in Education, 11: 353–369. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] described procedures for identifying sources of differential functioning for dichotomous data using differential bundle functioning (DBF) derived from the differential functioning of items and test (DFIT) framework (Raju, van der Linden, & Fleer, 1995 Raju, N. S., van der Linden, W. J. and Fleer, P. F. 1995. IRT-based internal measures of differential functioning of items and tests. Applied Psychological Measurement, 19: 353–368. [Crossref], [Web of Science ®] , [Google Scholar]). The purpose of this study was to extend the procedures for dichotomous DBF to the polytomous case and to illustrate how DBF analysis can be conducted with polytomous scoring, common to psychological and educational rating scales. The data set used was parent and teacher ratings of child problem behaviors. Three group contrasts (teacher vs. parent, boy vs. girl, and random groups) and two bundle organizing principles (subscale designation and random selection) were used for the DBF analysis. Interpretations of bundle indexes in the context of child problem behaviors were presented.