Extrapolated General Cognitive Indexes on the McCarthy Scales for Gifted and Mentally Retarded Children

Abstract

Although extrapolated IQs are available for Wechsler's intelligence scales, extrapolated values for the General Cognitive Index of the McCarthy Scales of Children's Abilities have not been presented. This study derived regression equations from the normative sample data and computed estimated composite raw scores corresponding to the indexes above 150 and below 50. Extrapolated values are useful for estimating a child's present level of functioning; however, because extrapolated values are not based on empirical data, they should be viewed as estimates and used with caution.