A MULTIDIMENSIONALITY-BASED DIF ANALYSIS PARADIGM

A multidimensionality-based differential item functioning (DIF) analys is paradigm is presented that unifies the substantive and statistical DIF analysis approaches by linking both to a theoretically sound and m athematically rigorous multidimensional conceptualization of DIF. This paradigm has the potential (1) to improve understanding of the causes of DIF by formulating and testing substantive dimensionality-based DI F hypotheses; (2) to reduce Type 1 error through a better understandin g of the possible multidimensionality of an appropriate matching crite rion; and (3) to increase power through the testing of bundles of item s measuring similar dimensions. Using this approach, DIF analysis is s hown to have the potential for greater integration in the overall test development process.