Comparative Efficacy of K-ABC Subtests VS. WISC-R Subtests in the Differential Classification of Learning Disabilities

Abstract

Comparison of IQ-subtest scores has gained new popularity with the recent introduction of the Kaufman Assessment Battery for Children (K-ABC). The present study addressed questions pertinent to the utility of K-ABC subtests in differentiating LD children from students classified as EMR, SEM, and referred but Unclassified. In addition, it directly compared the efficacy of K-ABC subtests vs. subtests from the Wechsler Intelligence Scale for Children-Revised (WISC-R) in this task. The sample consisted of 265 children (181 males, 84 females) referred for psychological evaluations; 171 were classified LD. The LD group was further divided into two subgroups: those who showed significant ability-achievement discrepancies (LDdisc; n = 42) and those who did not (LDno; n = 129). Hierarchical discriminant-function analyses showed that subtest scores from both the K-ABC and the WISC-R differentiated the LDdisc group from children in the other categories. However, subsequent classification analyses revealed that neither the K-ABC nor the WISC-R was capable of returning children to their correct placements. Results, therefore, indicate that subtest scores from the K-ABC and the WISC-R were incapable of enhancing the differential classification of LD over rates obtainable on the basis of chance.