II. The comparability of the WISC-R and WAIS among 16-year-old EMR children

Thirty 16-year-old EMR children were administered the WAIS and WISC-R in counterbalance order to determine the comparability of the two assessment instruments. The WAIS was found to yield significantly higher Verbal, Performance, and Full Scale IQ scores. The comparisons of corresponding subtests indicate that all WAIS subtests were significantly higher than the WISC-R except Picture Completion. Correlations between corresponding WAIS and WISC-R IQ scales and subtests, however, were significant. The results suggest differences between the two instruments among children of subnormal intelligence, thus presenting the possibility that a child may be differentially classified based on the selection of the intelligence test.     

Relationship of the WISC-R factors to the adaptive behavior scale-school edition in a referral sample

The Wechsler Intelligence Scale for Children-Revised (WISC-R) factor deviation quotients (DQ) were calculated for Verbal Comprehension (VCDQ), Perceptual Organization (PODQ), and Freedom From Distractibility (FDDQ) factors for 83 referred children aged 7 years, 5 months to 16 years, 2 months who received a psychoeducational evaluation. The DQs were then compared to the factor domain and Comparison scores of the Adaptive Behavior Scale-School Edition (ABS-SE) by separate stepwise regression analyses. The results indicated that the two significant models were Community Self-Sufficiency (F(3, 76)=6.67,p<.001,R²=.208) and the Comparison Score (F(3, 76)=7.30,p<.001, R²=.223). The VCDQ and Verbal IQ scores were essentially equal predictors of adaptive behavior, but the PODQ and Performance IQ scores were not predictive. It is suggested that practitioners using the ABS-SE consider the differential predictive characteristics of the Verbal IQ/VCDQ and Performance IQ/PODQ when making placement decisions and when predicting success in various programs. Verbal comprehension is presented as being a common construct that underlies the WISC-R and ABS-SE. The suggestion that cognitive processes enable persons to acquire skills that make performance of adaptive skills possible also is discussed.     

Relationship of scores on PPVT-R and WISC-R with special education children and youth

Comparisons of the Peabody Picture Vocabulary Test-Revised and the Wechsler Intelligence Scale for Children-Revised were made with 104 children diagnosed as learning disabled and mentally retarded. Significant but modest correlations were found between all but one of the WISC-R scaled scores (i.e., Coding) and PPVT-R standard scores, and between WISC-R IQs and PPVT-R standard scores. Significant differences were found among mean Verbal, Performance, and Full Scale IQs and mean PPVT-R standard scores. The PPVT-R standard scores underestimated WISC-R Verbal IQs by 7 points, WISC-R Performance IQs by 17 points, and WISC-R Full Scale IQs by 11 points.     

Factor analysis of responses to the WISC-R for gifted children

Several researchers have focused on the question of whether the traditional two-factor interpretation of WISC--R scores proposed by Wechsler (1974) is appropriate in selecting students to be admitted to gifted programs. Some researchers have suggested that the two-factor solution (Verbal and Performance) of Karnes and K. E. Brown provides the appropriate model, while others have proposed an alternative model based on exploratory research with gifted and average students. The current study expands exploratory findings of S. W. Brown with Rood in 1982 and Yakimowski in 1987, using confirmatory factor analytical procedures. The confirmatory factor analyses for selected groups of gifted (n = 158) and average (n = 195) students (M = 9.6 yr.) indicate that the alternative three-factor solution model may be a better system for interpreting the pattern of WISC--R subtest scores of gifted students than the conventional Verbal and Performance solution.     

Concurrent validity of the WISC-R factor scores

This study investigated the efficacy of predicting academic achievement as measured by the Wide Range Achievement Test using the factor scores of the Wechsler Intelligence Scale for Children-Revised as potential predictors. Both instruments were administered to 200 school children referred for psychological evaluations. Factor scores for the WISC-R were computed according to equations provided by Gutkin (1978). These factor scores then were regressed in a stepwise manner on the Reading, Spelling, and Arithmetic standard scores from the Wide Range Achievement Test. Stepwise regressions also were performed using the traditional Verbal and Performance IQs as the potential predictors. A comparison was made between the results obtained by use of the factors or the more common scores. The results indicated that the Freedom From Distractibility factor score significantly aided in the prediction of Reading and Spelling achievement and was of primary importance in predicting Arithmetic achievement. When the stepwise results using the different scores were contrasted, the factor scores accounted for appreaciably more variance in Arithmetic than did the traditional Verbal and Performance IQs. Derived regression equations are reported along with a discussion of the interpretability of the Freedom From Distractibility factor.     

Factor structure of the WISC-R with Anglos and Mexican-Americans

The present study compared the underlying factor structure of the Wechsler Intelligence Scale for Children-Revised for Anglo and Mexican-American children. Subtests of the WISC-R were administered to 109 Anglo and 123 Mexican-American children ranging from 8 to 15 years of age and were analyzed separately for each group. Three factors emerged for each ethnic classification which corresponded closely to those usually reported for the WISC-R. Coefficients of congruence (.84–.89) between factors given the same name for each ethnic group indicated a high degree of similarity in constructs being measured.     

Hemispheric asymmetry and recategorized WISC-R patterns in learning-disabled and nondisabled children.

The relationship between hemispheric processing and recategorized WISC-R patterns (spatial strengths and depressed Acquired Knowledge scores) in 14 learning-disabled and 14 nondisabled boys was examined. A genetic-prenatal hormonal basis appears most plausible.     

Predictive validity of the WISC-R with Mexican-American children

The reliability and predictive validity of the WISC-R was investigated with 46 Mexican-American children. Approximately a year and a half after the administration of the WISC-R, scores on the Iowa Tests of Basic Skills (ITBS) were collected. Internal consistency estimates for WISC-R subtests and composites were found to be comparable to those reported in the WISC-R manual. Correlations between WISC-R subtests and those of the ITBS ranged from modest for verbal subtests to mild when performance subtests were used as predictors. The best single predictor proved to be that of Verbal IQ, which accounted for some 40% of the variance in future achievement when measured by the ITBS. It was concluded that the WISC-R meets minimum requirements of reliability and predictive validity with Mexican-American children.     

Reliability and predictive validity of the WISC-R with native-American Navajos

The reliability and predictive validity of the WISC-R was examined with a sample of 40 Navajo children. Internal consistency reliability estimates of WISC-R subtests as well as composites were found to be low for the Navajo subjects as compared with the reliability coefficients reported in the WISC-R manual. Correlation coefficients between the WISC-R subtests and those of the Wide Range Achievement Test (WRAT) were low. Only the Block Design subtest correlated significantly with the WRAT-Spelling. The predictive validity of the WISC-R IQ scales was similarly found to be very low. Considering the nature and size of sample, cautions in generalizing these findings to other native-American populations are recommended.     

Comparison of the WISC-R and Woodcock-Johnson tests of cognitive ability

The relationship between the Woodcock-Johnson Tests of Cognitive Ability (WJTCA) and Wechsler Intelligence Scale For Children-Revised (WISC-R) was investigated in a referral sample of 52 elementary aged students. The WJTCA and WISC-R provided comparable ability estimates as reflected by a .74 correlation between the respective Full Scale scores and no significant (.05 level) mean difference (WJTCA Broad Cognitive Ability mean = 97.1, WISC-R Full Scale mean = 96.8). The comparability of the WJTCA/WISC-R global ability estimates is contrary to lower WJTCA scores found in recent studies with learning disabled students, with the current findings supporting the criticism of those studies as advanced by the author of the WJTCA.     

Comparing the Stanford-Binet,fourth edition to the WISC-R: A concurrent validity study

This study focused on the concurrent validity of the Stanford-Binet Intelligence Scale, 4th ed. (SB IV) and the Wechsler Intelligence Scale for Children-Revised (WISC-R) in a homogeneous, nonexceptional sample of 32 early elementary school children. Despite the limited nature of the sample, the findings suggested that the SB IV has a significant positive relationship with the WISC-R. The tests displayed a moderate level of common variance. Intercorrelations partially supported the SB IV authors' predictions of relationship between the two instruments.     

Race, social class and ability patterns on the WISC-R

The national standardization sample of whites and blacks on the Wechsler Intelligence Scale for Children—Revised (WISC-R) was the basis for a detailed analysis of the psychometric nature of racial and social class differences on the original 13 subscales of the WISC-R. The profiles of subtest scores of whites and blacks were compared directly and also after the racial groups were statistically equated on Full Scale IQ (FSIQ). Under the latter condition, the races differ only very slightly, although significantly, on some of the subtests, in ways generally contrary to popular expectations. The profile of white-black differences on the WISC-R subtests is markedly different, and negatively correlated with, the profiles of social class differences within each racial group, indicating that the pattern of racial differences is not explainable in terms of the difference in the average socio-economic status (SES) of blacks and whites. A Schmid-Leiman orthogonalized hierarchical factor analysis yields virtually identical factor structures and highly congruent factor loadings on the subtests for whites and blacks. Analysis of factor scores shows that by far the largest proportion of the variance between races is attributable to the general factor (g) common to all the subtests, whereas the group factors (verbal, performance and memory) contribute only minutely to the interracial variance. Hence the white-black differences on the diverse subtests of the WISC-R, and in the Full Scale IQ, are interpreted primarily as a difference in Spearman's g, rather than as differences in the more specific factors peculiar to particular content, knowledge, acquired skills or type of test. However, some slight but significant differences in patterns of ability also occur that are independent of g.