Extracting maximum validity from the WAIS.

Recent research (Feingold, 1982) on the incremental validity of the WAIS has found that the Vocabulary and Information subtests are each as valid as the Full Scale IQ. The present WAIS review demonstrated that weighting subtests that differ in validity equally in the computation of the IQ is responsible for reducing potential validity. Two main conclusions emerged from these data. One, Vocabulary and Information in concert yield a measure that has greater validity than either subtest by itself. Two, the addition of a third test in a stepwise multiple regression in which Vocabulary and Information already have been added will not result in a consistent increase in validity. These findings must be considered tentative, but can serve as a guide for devising research designs to validate the recent revision of the WAIS (WAIS-R).