The Calculation of the WISC-Ill General Ability Index Using Canadian Norms

Abstract

Since the publication of the Wechsler Intelligence Scalefor Children - Third Edition (WISC-III, 1991), several alternative scoring frameworks have been developed based on American norms. One such framework is the General Ability Index (GAI). The GAI provides a composite score using the eight subtests from the Verbal Comprehension Index (VCI) and the Perceptual Organization Index (POI). The GAI is an appropriate substitute for the Full Scale IQ score if the VCI and POI are considered better estimates of the child's verbal and nonverbal reasoning abilities than the Verbal IQ and the Performance IQ scores. The tables for calculating the GAI using Canadian norms are presented.