ESTABLISHING COVARIANCE CONTINUITY BETWEEN THE WISC-R AND THE WISC-III

Much of the research based on Wechsler Intelligence Scale for Children -Revised (WISC-R; D. Wechsler, 1974) subtest covariances may not valid ly be applied to the Wechsler Intelligence Scale for Children-Third Ed ition (WISC-III; D. Wechsler, 1991) without ascertaining whether the c ovariance structures of the normative samples for the two versions are equivalent. The covariance matrices for the WISC-R and the WISC-III w ere tested for equality by age group using the EQS Structural Equation s Program (P. M. Bentler, 1989). Chi-square tests revealed significant differences between the covariance matrices for 10- and 16-year-olds; however, the more stable normed fit index revealed essentially no dif ference across all age groups. It can be concluded that, for all pract ical purposes, covariation among WISC-III subtests does not differ fro m covariation among WISC-R subtests.