On the Relationship Between Item Stem Formulation and Criterion Validity of Multiple-Component Measuring Instruments.

The possible dependency of criterion validity on item formulation in a multicomponent measuring instrument is examined. The discussion is concerned with evaluation of the differences in criterion validity between two or more groups (populations/subpopulations) that have been administered instruments with items having differently formulated item stems. The case of complex item stems involving two stimuli description sentences (double-barreled questions) is thereby compared with the setting where items contained a single sentence. Using empirical data, the latent criterion validity differences are evaluated across three groups that are randomly assigned to conditions characterized by item stems with differing number of stimuli. The results indicate that validity of an instrument can be influenced by the specific way item stem is formulated. Implications for empirical educational, behavioral, and social science research are discussed.