DIFFERENTIAL BUNDLE FUNCTIONING USING THE DFIT FRAMEWORK - PROCEDURESFOR IDENTIFYING POSSIBLE SOURCES OF DIFFERENTIAL FUNCTIONING

A general framework for assessing differential functioning of items an d tests (DFIT) was recently proposed. Both unidimensional and multidim ensional tests with either dichotomous or polytomous scoring can be ha ndled within this framework. In this study, the DFIT framework is expa nded to include differential bundle functioning (DBF) as a mechanism f or identifying possible sources of differential functioning. This expa nsion is illustrated with an empirical (reading comprehension) data se t consisting of a gender comparison and a socioeconomic status compari son with 1,000 participants in each group. Bundles on this particular test that exhibited large DBF include a reading passage that favored b oys over girls, possibly due to its context. The theoretical and pract ical implications of the use of DFIT for identifying possible sources of differential functioning are discussed.