K-ABC and McCarthy scale performance among “at-risk” and normal preschoolers

Abstract

This study assessed the degree of comparability between the McCarthy Scales of Children's Abilities (McCarthy) and the Kaufman Assessment Battery for Children (K-ABC) for 51 “at-risk” (Low Birthweight, Head Start, and Developmentally Delayed) and 33 “normal” preschool children. The K-ABC Mental Processing Composite (MPC) and McCarthy General Cognitive Index (GCI) correlated significantly for both groups, but was significantly greater for the at-risk preschoolers. The at-risk group achieved a significantly higher mean MPC than GCI, while the normal comparison subjects achieved a slightly lower mean MPC. As reflected in previous studies, the GCI seems to provide an accurate estimate of the at-risk child's typical classroom performance. While the MPC may afford an estimate of such children's capacity for academic growth, if provided appropriately tailored remediation, it may also be missing critical aspects of children's cognitive functioning. Mean score discrepancies for at-risk preschoolers were discussed in relation to the theoretical and psychometric properties of the K-ABC and McCarthy.