Two- and Four-Subtest Short Forms of the WAIS–R: A Comparative Validity Study with a Normal Sample

Short forms of WAIS–R using selected subtests were investigated with 80 university student volunteers. The short forms included Silverstein's (1982) two- and four-subtest short forms and the quick two- and four-subtest short forms of Kaufman, Ishikuma, and Kaufman-Packer (1991). The accuracy of short-form IQ estimates were compared for the short form administered first followed by the remaining subtests and the short form included in a standard full administration. Specific validity criteria were mean IQ difference, correlation between IQ scores, accuracy relative to the 95% confidence limits for Full Scale IQ, and correspondence between IQ categorizations. The results supported the concurrent validity of the four-subtest short forms. Just as importantly, the results confirm a 1986 study by Thompson, Howard, and Anderson which drew attention to some subtest short forms performing differently as discrete entities than when embedded in full administrations. The results of this study reiterate this concern for Silverstein's short form using two subtests but not for either of the short forms using four subtests.