The relationship between the Wechsler intelligence scale for children-revised (WISC-R), a short form (WISC-RSH), and the wide range achievement test (WRAT) in learning disabled students

The purpose of this study was to determine if the Split-Half Short Form WISC-R correlates over time with the WISC-R and whether either of these two separately administered measures of intellectual ability were able to predict academic achievement in a sample of learning disabled students using the WRAT as the criterion variable.The subjects were 100 (71 males, 29 females) students, ages, 6 through 16, selected from a special education learning disabled school population. All the subjects were administered the WISC-R an average of three years prior to the administration of the WISC-RSH and the WRAT.Two hypotheses were specified for the separately administered test forms: No significant difference between corresponding scales of WISC-R and WISC-RSH; and no difference in ability of corresponding WISC-R and WISC-RSH scale scores in predicting academic achievement using the WRAT Reading, Spelling, and Arithmetic standard scores. Pearson Product-Moment correlation analyses were used to determine if a significant relationship existed between Verbal, Performance and Full-Scale IQ scores of the WISC-R and WISC-RSH. Regression analysis procedures were used to determine the predictive validity of each of these measures to the WRAT subscales.The results revealed that the Verbal, Performance and Full Scale IQ scores of the WISC-R and the WISC-RSH were significantly correlated (r=.60, .69, .72, respectively) over the three year period.Indices of predictability obtained from regression procedures revealed that neither test form was able to predict academic achievement using the WRAT scores as the criteria. However, both test forms performed similarly in their predictive ability, with the WISC-RSH demonstrating a slightly better predictive ability than the WISC-R. This can be explained by the fact that the WISC-RSH and WRAT were administered concurrently three years after the WISC-R.Results from this study show promise that the WISC-RSH, Verbal, Performance and Full Scale IQ scores may be used in the re-evaluation assessment process of learning disabled students. It remains open to question whether the WISC-RSH can be used in place of the WISC-R for all special education students in light of what previous studies have demonstrated regarding the WISC-R's ability to predict academic achievement in other exceptional sample populations.Department of Educational PsychologyThesis (Ph. D.