Commonality of Diagnostic Categories for Students Assessed on the K-ABC and WISC-R

Abstract

The K-ABC and the WISC-R were administered in a counterbalanced order as part of a psychoeducational battery to 164 children referred to an urban school mental health center for academic problems. The study compared the extent of agreement in the diagnoses of learning disability and mental retardation based on these instruments. Diagnoses were made by experienced clinicians who had access to only one of the two test profiles (K-ABC or WISC-R). While statistically significant overlap in diagnostic decisions between the K-ABC and WISC-R was found, a large number of children received different diagnoses based on the two tests. When different diagnostic decisions were made, the differences were likely to be conservative. For instance, Learning Disabled with one instrument became No Diagnosis with the second instrument, rather than Mentally Retarded. The most significant data for prediction of diagnosis were the cognitive measure (either WISC-R or K-ABC), plus a measure of achievement.