A Comparison of the WISC-R and WAIS-R Performance Scales in Deaf Adolescents

Abstract

Scores from the WISC-R and WAIS-R Performance Scales were compared using a sample of 32 deaf adolescents. Performance scores were obtained during routine evaluations (mean interval between tests = 41.6 months). Results show that the two scales produce virtually identical scores. WISC-R and WAIS-R subtest scores and PIQs are correlated (all rs > .470, p < .008). Observed correlations are not significantly different from maximum possible correlations, with the exceptions of the Picture Completion subtest and Performance IQs. Differences between means are nonsignificant, but WISC-R Picture Completion and Block Design variances are significantly larger than their respective WAIS-R variances (p < .008). On the strength of these findings, psychologists are cautioned regarding the equivalence of the Picture Completion subtest in the two scales, although practitioners may directly compare other WISC-R and WAIS-R Performance Scale scores in deaf adolescents.