Diagnostic use of the WISC-R and McCarthy Scales: A regression analysis approach to learning disabilities

Abstract

Thirty learning disabled and 30 nonlearning disabled students were individually administered the WISC-R, McCarthy Scales of Children's Abilities, and the Wide Range Achievement Test. Regression analyses were conducted to determine the combination of scores from the WISC-R and McCarthy Scales that best predicted the achievement level of the subjects. In addition, the scores that best predicted group status (LD or nonLD) were determined. In general, the WISC-R Comprehension, Arithmetic, and Object Assembly, and the McCarthy Quantitative and Memory Indices were most sensitive to the LD students' achievement. Conversely, the WISC-R Similarities and Arithmetic and the McCarthy Verbal Index were most sensitive to the achievement of nonLD students. Finally, the McCarthy Perceptual-Performance Index and the WISC-R Vocabulary subtest best discriminated group status. The diagnostic implications of these results were discussed.