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 ≤ 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. © 2007 Wiley Periodicals, Inc. J Clin Psychol 63: 1145–1152, 2007.