A COMPARISON OF THE PERFORMANCE OF COGNITIVELY DISABLED-CHILDREN ON THE WISC-R AND WISC-III

This study compared differences in performance on the WISC-III and on the WISC-R. Sixty-one students with learning impairments, due for reev aluation of their special education placement, were administered the W ISC-III as part of a psychological assessment battery. Results indicat e a mean difference between WISC-R and WISC-III FSIQ of 7.95 points, w hich is similar to WISC/WISC-R comparisons. Substantial differences th at averaged 9.21 points were found between WISC-R and WISC-III PIQ mea ns. These findings suggest that for a special education sample an aver age decrease of at least 8 points can be expected on the WISC-III Full Scale IQ. Caution should be exercised when one is considering changes in educational classification or interpreting qualitative differences in performance on WISC-III scores compared with WISC-R scores.