Validity of the Woodcock-Johnson tests of cognitive ability: A comparison with the WISC-R in LD and normal elementary students

The study addresses the external validity of the Woodcock-Johnson Tests of Cognitive Ability (WJTCA) in learning disabled (LD) elementary school children by controlling for two methodological errors Woodcock identified in previous studies: (a) Intellectual ability range was restricted for both normal and LD samples to counteract an artificial inflation of mean WISC-R scores without concomitant effect on WJTCA scores, and (b) the WISC-R was readministered during data collection. In addition, normals were used as controls for LD students. WJTCA scores were correlated and compared with WISC-R scores and reading achievement test scores in 20 normal, 20 mild-to-moderate LD, and 20 severe LD third-, fourth-, and fifth-grade students. Results indicate comparability of mean WISC-R and WJTCA Full Scale scores in the normal sample, but manifest a significantly lower WJTCA Full Scale scores in the LD samples, despite a strong degree of correlation between the two tests in each sample. The significant linear trend of increasing mean WISC-R/WJTCA discrepancy across the severity of LD strongly suggests that the lower WJTCA scores in the LD samples is a function of the instrument's achievement emphasis and refutes the possibility of systematic error in the WJTCA norms. Results suggest that the WJTCA's achievement emphasis jeopardizes its validity for assessing and classifying LD students within the currently accepted and mandated ability-achievement discrepancy model of specific learning disabilities.     

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.     

Comparison of PPVT-R and WISC-R in a mild/moderate handicapped sample

The Peabody Picture Vocabulary Test-Revised, Form L was compared with the Wechsler Intelligence Scale for Children--Revised with a sample of 32 mild/moderate handicapped students (24 boys, 8 girls). Significant correlations were found between the WISC-R Full Scale IQ (.46) and the WISC-R Verbal IQ (.50) and the PPVT-R, but no significant correlation was found between the WISC-R Performance IQ and the PPVT-R (.34). Mean scores on the PPVT-R and WISC-R were significantly different.     

Concurrent and predictive validity of the Kaufman Assessment Battery for Children with a Navajo sample

The aim of this investigation was to examine the mean scores and predictive validity coefficients obtained from the Wechsler Intelligence Scale for Children-Revised (WISC-R), the Kaufman Assessment Battery for Children (K-ABC), and the Peabody Individual Achievement Test (PIAT). The K-ABC and the WISC-R were administered 1 week apart in counterbalanced order to 35 Navajo children aged 6–12$\text{1}\text{2}$ years (mean 8–9 years), followed 10$\text{1}\text{2}$ months later by administration of the PIAT. The K-ABC yielded an overall mean of 95.0, which is significantly higher than the WISC-R Full Scale IQ mean of 86.9. All WISC-R and K-ABC global scores correlated significantly except the WISC-R Verbal and K-ABC Nonverbal scales. The WISC-R Verbal and Full Scale IQs and all five K-ABC scales correlated significantly with the PIAT Total Test standard scores. However, the K-ABC Achievement scale correlated significantly higher with the PIAT Total Test than with the WISC-R Verbal and Full Scale IQs. The implications of these findings are discussed.     

Clinical utility of the WISC-R and the French Pictorial Test of Intelligence with native American primary grade children

Cultural bias and the clinical utility of the WISC-R and French Pictorial Test of Intelligence were evaluated using scores of 22 male and 22 female Navajo primary grade children. There were no significant differences in performance on either test according to sex. As expected, the Verbal IQ and Full Scale IQ of the WISC-R and the Deviation IQ of the French provided significantly depressed estimates of ability. A prorated Performance IQ might be the least depressed measure of potential among these children.     

WISC-R and K-ABC comparison for matched samples of black and white children

The present study examined the performance of matched pairs of black and white fourth and fifth grade males and females on the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Kaufman Assessment Battery for Children (K-ABC). A total of 86 whites (40 males and 46 females) and 86 blacks (40 males and 46 females) were individually matched on age, gender, school, and socioeconomic status. The scores are as follows: the mean WISC-R Full Scale IQ (FSIQ) for blacks was 92.3 (SD=11.6) and for whites was 101.3 (SD=11.6) and the mean K-ABC Mental Processing Composite score (MPC) for blacks was 91.5 (SD=10.1) and for whites was 97.5 (SD=10.6). These findings suggest that black children will likely earn very similar WISC-R FSIQ and K-ABC MPC mean scores. Additionally, Kaufman and Kaufman's conclusion that use of the K-ABC reduces the difference between black and white levels of intelligence by one half in comparison with values found using the WISC-R was not supported.     

Common variance among three measures of nonverbal cognitive ability: WISC-R performance scale,WJPB-TCA reasoning cluster,and Halstead category test

The relationships among two psychometric measures of nonverbal cognitive ability (1) the Wechsler Intelligence Scale for Children-Revised (WISC-R) Performance IQ and (2) the Reasoning Cluster score and two subtests, Analysis-Synthesis and Concept Formation, from the Woodcock-Johnson Psychoeducational Battery-Tests of Cognitive Ability (WJPB-TCA)- and a neuropsychological test of abstract reasoning and concept formation (Halstead Category Test) were examined for a population of 25 children referred for psychoeducational evaluation as a result of learning difficulty. The findings demonstrated that the WISC-R Performance IQ and the Halstead Category Test have a common variance and appear to be sensitive to nonverbal cognitive ability, particularly of a perceptual organization nature. In contrast, the Reasoning Cluster score and the individual subtests from the WJPB-TCA appear to have a substantial g loading, as well as significant language correlates.     

I. Validity of WISC-R factor scores in predicting achievement and attention for four sociocultural groups

The predictive validity of WISC-R factor scores was examined with samples from the four sociocultural groups of Anglo, Black, Chicano, and native American Papago. The Full Scale IQ and Verbal Comprehension (VC) factor scores were significantly better predictors of achievement as measured by teacher ratings and the Metropolitan Achievement Test. The Perceptual Organization and Freedom from Distractibility (FD) factor scores were also significantly related to achievement, but at a lower level than Full Scale and VC. The correlations of the WISC-R and achievement measures were nearly the same for three of the four groups (exception was native American Papago). The relationship of the FD factor score to ratings of attention was statistically significant, but relatively low. Cautions in interpreting FD as a measure of attention were recommended due to overlap of distributions and low proportion of variance in attention accounted for by FD.     

Use of the Peabody Picture Vocabulary Test with the educationally handicapped

Despite widespread use of the Peabody Picture Vocabulary Test (PPVT) as a measure of intelligence for educationally handicapped students, few studies have related PPVT scores of such students to their scores on the Wechsler Intelligence Scale for Children (WISC). Using 100 public school students consecutively referred for learning difficulties, their mean PPVT IQ (97.75) was found to be consistently and significantly higher than WISC Full Scale IQ (89.65), Verbal IQ (88.68), and Performance IQ (92.73). Correlations between the PPVT IQ and the WISC Full Scale, Verbal, and Performance IQs were .70, .69, and .54, respectively. A tabular summary of previous studies comparing PPVT and WISC IQs is included.     

Correlations among GPA and scores on the Spanish version of WISC-R and the Woodcock-Johnson Achievement subtests for 10- to 12-year-old Puerto Rican children

The purpose of this study was to explore the correlations among GPA, the Spanish version of the WISC-R, and the Woodcock Johnson Achievement subtests for a group of Puerto Rican children. The tests were administered to a sample of 32 children between the ages of 10 to 12 yr. in Grade 4. Pearson correlations between the Verbal, Performance, and Full Scale scaled scores in the WISC-R (Spanish Edition) ranged between .37 to .83. Correlations between subtests of the Woodcock-Johnson Achievement Test ranged from .26 to .70. The moderate correlation between the Total scaled scores on the Woodcock-Johnson and the scaled scores of the Performance, Verbal, and Full Scales of the Spanish WISC-R is indicative of the value of these Spanish-language instruments in diagnosing the intellectual and academic performance of Spanish-speaking populations in the United States.     

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.     

Stability of WISC-R scores for a sample of learning disabled children

The study was designed to assess the stability of WISC-R profiles of 36 learning disabled children given the WISC-R two times. The mean time between tests was 2.5 yr. The pattern reported for learning disabled children on Bannatyne's categories was evident for the group at both times, however, this pattern was not found for the majority of subjects. Analysis indicated a decrease over time in Verbal IQs, Full Scale IQs, and Bannatyne's Conceptual category, confirming previous findings. Possible reasons for the changes in scores are discussed.     

Inspection time and intelligence in 7-yr-old children: A follow-up

Remeasures of inspection time (IT) were obtained from 30 of the 47 children reported in Nettelbeck and Young (Personality and Individual Differences, 10, 605–614, 1989). Ages ranged from 7 yr–0 months to 7–11 and Full Scale IQ (WISC-R) ranged from 93 to 142 (mean = 116.5 SD = 12.2). Correlations between IT and the WISC-R subtests, scales and factors used in the earlier study were generally statistically significant: and similar to those found earlier. The correlation between IT and Full Scale IQ was — 0.49, with those children whose IQs were below the median score of 116 again contributing more to this outcome. Similarly, the IT-IQ correlation was higher among children showing less well-directed attention in the IT task. Once again IT correlated better with Verbal IQ, supporting the hypothesis that IT is better associated with more general intellectual functioning than with specific cognitive abilities. Cross-lagged panel correlations between IT and IQ were —0.40, whether predicting IQ from IT or the reverse. Thus, there was no evidence for a causal relationship between these variables, although both may reflect a common cognitive ability factor.     

The validity of the general ability measure for adults: comparison with WAIS-R IQ scores in a sample of college students with academic difficulties

The present study investigated the validity of the General Ability Measure for Adults (GAMA) by comparing it to the WAIS-R using a sample of 80 college students reporting learning difficulties. Results indicated that the mean GAMA IQ score did not deviate significantly from the mean WAIS-R IQ scores. The GAMA Full Scale IQ correlated significantly with the WAIS-R PIQ, VIQ, and FSIQ scores. However, the obtained correlation coefficient for the GAMA and WAIS-R PIQ significantly differed from the observed correlation coefficient between the GAMA and WAIS-R VIQ, suggesting that the GAMA was more clearly associated with perceptual skills than verbal abilities. When the correlation coefficients between the GAMA and WAIS-R scores were corrected for the effects of range restriction, the correlation coefficients increased, yet demonstrated the same pattern (e.g., GAMA/PIQ,.69; GAMA/VIQ,.36; GAMA/FSIQ,.60). The GAMA s accuracy in predicting individual student performance on the WAIS-R FSIQ also was examined.     

The WISC-III: A reality check

Although the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) is arguably the best instrument currently available for assessing students' intelligence, its use will present practitioners, especially school psychologists, with some unique challenges. Recent research suggests that significant reductions in special education students' WISC-III Verbal, Performance, and Full Scale IQ scores will be found, compared with their previous WISC-R results. This finding will have a profound impact on special education placement decisions. Specifically, students who were previously found eligible for learning disability programs may now no longer evidence the significant discrepancies necessary in order to receive continued services. Conversely, students earlier identified as “slow learners” may now be eligible to receive services for those classified under the category of educably mentally handicapped. In addition, the notion that the WISC-III may underestimate the ability of certain populations of students requires further exploration. This article will address these issues as well as implications for practitioners presently administering the WISC-III.     

The effects of positive examiner verbal comments on the total WISC-R performance of institutionalized EMR students

Forty educably mentally retarded (EMR) students were randomly selected and assigned to one of two treatment groups. Students in the experimental group were verbally praised after their responses to the WISC-R questions, while the students in the control group received nonevaluative procedural comments. The scaled scores for five of eleven subtests, in addition to the Verbal, Performance and Full Scale indices, were significantly greater under the experimental procedure. The treatment's efficacy and considerations for future research were noted and discussed.     

Learning style and intelligence of reading disabled students

This study examined the relationship between elements of the Learning Style Inventory and various scales of the WISC-R for reading disabled students. Previous research generally suggests that reading disabled students have preferences that tap the visual-spatial domain and have higher WISC-R Performance Scale and subtest scores than Verbal Scale and subtest scores. Subjects with IQs of 90 or better on either the Verbal or Performance Scales of the WISC-R and a consistency score of 75 or better on the inventory were selected. Contrary to what might be expected, data generally showed a nonmeaningful pattern of correlations between scales of the Learning Style Inventory and WISC-R Performance-type functioning. However, as an important part of the validation of the inventory, lack of association between the two can be interpreted as support for its construct validity.     

Performance of students with learning disabilities on validity indexes of the Perception of Ability Scale for Students.

The present study examined the performance of 78 students with learning disabilities and 71 normally achieving students in regular Form 1 (Grade 6) classes on three validity indexes of the Perception of Ability Scale for Students, a measure of academic self-concept. The three indexes assess consistency of responding, negative or positive response biases, and misrepresentation of self-perceptions in terms of unrealistic perceptions of perfection in school. Analysis showed that learning disabled students obtained significantly lower Full Scale scores than the normal students, but no significant differences appeared on the three validity indexes. Users of the test can be confident that learning disabled students respond to items in as valid a manner as other students. Having specific learning problems in school should not interfere with response patterns on this scale.     

Relationship between intellectual status and reading skills for developmentally disabled children

The relationship between WISC-R Full Scale IQ and scores on the Woodcock Reading Mastery Tests were explored for 80 developmentally disabled children. While the children's reading skills correlated moderately and significantly with intellectual status, abstract reading skills, e.g., word comprehension, correlated more highly with Full Scale IQ than did concrete ones, e.g., word identification. The development of concrete learning patterns by such children was discussed, with an emphasis on the emotional importance of these learning styles to the children and their families.     

Bender-Gestalt developmental scores: predicting reading and mathematics achievement

This study examined the relative importance of perceptual-motor processes and intelligence in predicting reading and mathematics achievement of children of low birthweight. Subjects were two groups of 153 children, ages 6 to 12 years, of either low (3 lb. or below, n = 72) or normal birthweight (n = 81) who participated in a comparative study on sequelae of children of low birthweight. To examine the utility of the Bender-Gestalt test in predicting academic achievement, Bender developmental scores, WRAT reading and mathematics scores, and WISC-R Full Scale IQs from both groups were compared and then intercorrelated separately. The mean comparisons indicated that children of low birthweight scored significantly lower on both Bender scores and reading achievement and had lower IQs than those of normal birthweight. Bender scores also appeared to have more utility for predicting reading and mathematics achievement for children of low birthweight than for those of normal birthweight.