Multiple regression data using the WISC-R and the Woodcock-Johnson tests of cognitive ability

Abstract

University of Missouri- Columbia Yourh Services ColumbiaUsing a sample of 100 behavior disordered male adolescents, correlations between the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the WoodcockJohnson Tests of Cognitive Abilities (WJTCA) were computed. All WISC-R subtests correlated with the W-J Broad Cognitive Ability score at the .0001 level. Analysis of the forward selection multiple regression procedure resulted in the inclusion of only WISC-R Verbal subtests for the first six steps. Implications of such results were discussed and a predictive equation reported.Since its development, the Woodcock-Johnson Tests of Cognitive Abilities (1977) has received mixed reviews concerning its validity in relation to the WISC-R. Reeve, Hall, and Zakreski (1979) reported a correlation of .79 between the two instruments with a sample of learning disabled students. However, a discrepancy of almost one standard deviation was found between the two instruments, with the WISC-R being the higher. These authors offered two hypotheses concerning the discrepancy. First, the WoodcockJohnson may be tapping an area of cognitive functioning in which children with learning problems have greater difficulty than normals. A second suggestion was that the norms of the WJTCA could be in error. Ysseldyke, Shinn, and Epps (1981) reported that the WJTCA had a higher correlation with the WISC-R Verbal IQ than with the WISC-R Performance IQ. Using a sample of 50 learning disabled students, a correlation of .67 was computed between the WISC-R VIQ and the WJTCA Broad Cognitive score, while the PIQ yielded a correlation of only .48. Further, the LD students in this sample scored 7.68 points lower on the WJTCA than they did on the WISC-R FSIQ. These authors concluded that the WJTCA assesses product-dominant or crystallized intelligence, rather than fluid intelligence, with fluid intelligence being the processes necessary for the acquisition of academic skills (Cattell, 1963). What is learned or acquired through these processes is product-dominant intelligence. McGrew (1983), using a sample of 52 elementary students referred to child study teams for a variety of problems, concluded that the WISC-R and WJTCA provided comparable ability estimates. The correlation between the WJTCA Broad Cognitive Ability score and the WISC-R FSIQ for this sample was .74. Phelps, Rosso, and Falasco (1984), using a sample of 55 behavior disordered adolescents, found a correlation of .84 between the WISC-R FSIQ and WJTCA Broad Cognitive Ability score. There was only a 2.33 point discrepancy between the mean scores of the two instruments, t(54)=2.23, p>.03, with the WISC-R FSIQ being the higher of the two. The authors further found that the Broad Cognitive score was more highly correlated with the WISC-R VIQ (.90) than with the WISC-R PIQ (.68). Analysis of Pearson product-moment correlations between each WISC-R subtest and the Broad Cognitive score resulted in a range of .42 to S O for the Performance subtests, while for the Verbal subtests the range w...

Factor analysis of the Woodcock-Johnson with conduct disordered adolescents

“…Cummings and Moscato (1 984) demonstrated equivalent correlations between the Broad Cognitive Ability score to each of the four areas of achievement and between the four Scholastic Aptitude clusters to their respective areas of achievement on the W-J Achievement clusters. Finding results comparable to those of Cummings and Moscato, Phelps and Rosso (1985) concluded that the Scholastic Aptitude clusters lacked sufficient differentiation to justify computation when used with behavior disordered (ED) youth. Woodcock (1984) justified the continued use of these clusters by stating that they were not confounded with achievement, that they reduced testing time, that they provided discrepancy norms for each area of achievement, and that they provided higher clinical validity.…”

“…Such reasons are quite warranted if the clusters are distinct and separate functions. However, for the BD population, the lack of discriminant validity between the various Aptitude-Achievement pairings would lend doubt to that premise (Phelps & Rosso, 1985).It would appear that the four Cognitive Ability clusters of the W-J might also lack specificity. These clusters (Verbal Ability, Reasoning, Perceptual Speed, and Memory) were designed to "provide information regarding special intellectual abilities that may influence school learning and certain other kinds of performance" (Woodcock, 1984, p.357).…”

“…Such reasons are quite warranted if the clusters are distinct and separate functions. However, for the BD population, the lack of discriminant validity between the various Aptitude-Achievement pairings would lend doubt to that premise (Phelps & Rosso, 1985).…”