Differential item functioning in attitude assessment

Abstract

Differential item functioning (DIF) is not often seen in the literature on attitude assessment. A brief discussion of DIF and methods of implementation is followed by an illustrative example from a program evaluation, using an attitude-towards-science scale with 1550 children in grades one through six. An item exhibiting substantial DIF with respect to gender was detected using the Mantel-Haenszel procedure. In a second example, data from workshop evaluations with 1682 adults were recoded to a binary format, and it was found that an item suspected of functioning differentially with respect to age groups was, in fact, not doing so. Implications for evaluation practice are discussed.