Score Changes from the WISC-R to the WISC-III in Disabled Population in Kentucky
Abstract
This study was conducted to examine the extent of score changes from the Wechsler Intelligence Scale for Children-Revised (WISC-R) to the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) when administered to Learning Disabled and Mild Mental Disabled populations. Specifically, this study examined whether there are differences, or, differential score changes between these populations from one test version to the next. Score changes were obtained from 7 school districts in Western Kentucky. Recorded were scores from the WISC-R and WISC-III administrations in the areas of Verbal, Performance, and Full Scale IQ scores. The information collected about the children included date of birth, dates of testing, area of disability, gender, and race. Scores were then analyzed by a paired 1 statistic and three, two-way ANOVAs (Disability Group x WISC version). The results indicated WISC-III scores were significantly lower than WISC-R scores for both LD and MMD groups. The LD group also scored significantly higher than the MMD group across the two tests. The LD and MMD group scores changed approximately the same amount, as there was no interaction found between group and test version. Difference scores indicated that on average the total group's score changes from the WISC-R to the WISC-III were 3.67 for the Verbal Scale, 7.56 for the Performance Scale, and 5.65 for the Full Scale. Mean score changes for the LD group were 4.32 for the Verbal, 7.85 for the Performance, and 6.07 for the Full Scale. For the MMD group, the mean score changes were 2.39 for the Verbal, 8.26 for the Performance, and 5.83 for the Full Scale. Results of the present findings were discussed relative to previous findings in the literature. Implications for practice are made.