Validity of two selected-item short forms of the WAIS-III in an intellectually deficient sample

Various short forms of the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III; D. Wechsler, 1997) have been investigated, but limited information is available regarding the usefulness of any WAIS-III abbreviation with intellectually deficient individuals. Our study compared the validities of two WAIS-III selected-item short forms in a sample of 59 individuals with full scale IQs (FSIQs) of 79 or lower. The performance of both short forms was adequate, but the results gave a consistent edge to an adapted version of the Satz-Mogel (1962) short form in comparison to the abbreviated form by J. H. Wymer, K. Rayls, and M. T. Wagner (2003). The correlation (r = .98) of Satz-Mogel estimates with WAIS-III FSIQ scores was slightly higher than the correlation (r = .97) for estimates from Wymer et al.'s abbreviated form, and Satz-Mogel estimates did not differ significantly from actual FSIQs. In comparison to individual classification (FSIQ > 70 versus FSIQ < or = 70) obtained with the full WAIS-III, the misclassification rate was somewhat lower for the Satz-Mogel short form. Although both short forms performed reasonably well, practitioners should be cautious when utilizing any short form to make decisions about individuals.