Stability of wisc-r IQS: An investigation of ethnic differences over time

This investigation examined the 3-year stability of WISC-R IQs for a balanced sample of anglo, black, and Mexican-American handicapped children. No significant differences in mean IQs were found across the three ethnic groups, although over the 3-year test-retest period, WISC-R Verbal and Performance IQs were observed to vary significantly. Specifically, Verbal IQs decreased by an average of 2 points, while Performance IQs increased by an average of nearly 3 points. It was concluded that although statistically significant, the influence of 3 years time on the intelligence test performance of this varied ethnic sample of handicapped children was clinically insignificant.