The comparability, equivalence, and parallelism of the
Wechsler Adult Intelligence Scale - Revised (WAIS-R) and the
Wechsler Intelligence Scale for Children - Third Edition (WISCIII)
was compared using 16 year old youth. A total of 46
subjects, including 16 males and 30 females, were administered
the WAIS-R and the WISC-III in a counterbalanced order. The
WAIS-R was administered first to 23 subjects, while 23 subjects
were administered the WISC-III first, with an average retest
interval of 40 days. Repeated measures multivariate analysis of
variance (MANOVA) and univariate repeated measures analyses
(ANOVA) were used to examine significant test, administration
order, and practice effects. The means of the corresponding
summary IQs were significantly higher for the WAIS-R than the
WISC-III. A clear pattern of practice effects was displayed when
the WAIS-R followed the WISC-III. With the exception of two
subtests, the means on the WISC-III were significantly higher
than the corresponding means on the WAIS-R. The pattern of
practice effects for the subtests was ambiguous. Finally, ttests
examined the differences in correlated variance, and
Votaw's (1948) test of compound symmetry was employed to compare
covariances. The results of these tests showed minor
differences. Clinical and theoretical implications of these
results are discussed
