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.     

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.     

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.     

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.     

Teachers' and mothers' academic achievement expectations for learning disabled children

The present study investigated teachers and mothers academic achievement expectations for learning disabled and normally achieving grade 3 children. Both groups had similar WISC-R mean Full Scale IQ scores, ages and socioeconomic backgrounds. It was found that teachers and mothers had significantly lower academic expectations for learning disabled children. The results are discussed in terms of the importance of positive affective development for learning disabled children and the need for more encouraging attitudes on the part of teachers and parents.     

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.     

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.     

Test of the definition of learning disability based on the difference between IQ and achievement

A learning disability is commonly defined as a discrepancy between IQ and achievement. This has been criticized for identifying too many children as having a learning disability who have high IQs and average academic achievement. Such overidentification as actually occurred was assessed in 473 referred children (8-16 years, M= 10, SD=2) with normal intelligence. Learning disability was defined as a significant discrepancy (p<.05) between predicted and obtained achievement in reading, mathematics, or written expression on the Wechsler Individual Achievement Test. Predicted achievement was based on the child's WISC-III Full Scale IQ. Overidentification was considered to occur when a child scored at or above age level in reading, mathematics, and writing but still had a significant discrepancy between predicted and obtained achievement by virtue of a high IQ. Learning disability was diagnosed in 312 (66%) of the children. There was no overidentification because all children had one or more WIAT scores below the normative level for their age, i.e., < 100. Further, only 7% of the children were identified with a learning disability based on a WIAT score in the 90s. These children had a mean IQ of 123 and were rated by their teachers and parents as having learning problems.     

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.     

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.     

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.     

Long-term predictive validity of the WPPSI and the WISC-R with black school children

The WPPSI was administered to a group of 169 black, culturally deprived (Headstart) children prior to their entry into the first grade. Four years later, 94 of these children were tested with the WISC-R and 12 years later, 40 of the children were tested with the WAIS-R. In addition, the WRAT, ITBS, CAT, and ITED were administered in the first, fifth, eighth and eleventh grades respectively. Complete grade records were also obtained for the children for grades 1 through 11. Correlations for Full Scale IQs on the WPPSI/WISC-R, WPPSI/WAIS-R and WISC-R/WAIS-R were 0.78, 0.73 and 0.78, respectively. Highly significant correlations were obtained between Wechsler IQs and achievement test scores, overall grade point averages and grade point averages in particular subject areas across all grade levels. The results demonstrated a high degree of stability in intellectual functioning over the elementary and secondary school years and offer evidence that strongly supports the long-term validity of the WPPSI and WISC-R.     

Concurrent validity of the Woodcock-Johnson psycho-educational battery with regular and learning-disabled students

A comparison of the WISC-R and the Woodcock-Johnson Psycho-Educational Educational Battery (W-J) was made for children with regular and learning-disabled (LD) class placement. The W-J and Wechsler Intelligence Scale for Children-Revised (WISC-R) evidence low to moderate correlations and significant mean differences, indicating that the two tests are measuring somewhat different abilities to somewhat differing degrees. W-J—WISC-R correlations for the regular students exceed those of the LD students in the greater majority of the cases. Rank ordering of the WISC-R subtests and the W-J clusters indicate, as might be expected, that the LD students fare the worst in the WISC-R academic subtests (Arithmetic, Information and Vocabulary) and in the W-J academic clusters. More research needs to be conducted with the W-J before it should be adopted for use in the placement of exceptional children.     

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.     

An analysis of the conceptual framework underlying definitions of learning disabilities

Various theoretical perspectives have contributed to the different types of definitions of learning disabilities (LD) that have been developed since the category was first established. To date, there has been little consensus on the definition of learning disabilities. In the present study, three kinds of definitions, ability-achievement discrepancy, low achievement, and scatter, were examined to determine the extent to which there was common variance. The subject were 48 school-identified LD children and 96 non-LD children. Both samples had previously been administered a battery of psychoeducational tests. These data were used to classify each child as LD or non-LD according to each of 14 operational definitions. A factor analysis resulted in two distinct groupings of LD students; low achievement accounted for over four times as much variance as ability-achievement discrepancy. Scatter did not contribute independently to classification. The implications for LD-identification practices are discussed.     

Comparison of the Luria-Nebraska Neuropsychological Battery-Children's Revision and the WISC-R with learning disabled children

This investigation concerned the relationship between the Luria-Nebraska Neuropsychological Battery--Children's Revision and the WISC--R for a sample of 32 children identified as learning disabled. The children's mean age was 9 yr., 11 mo.; they were identified as learning disabled on the basis of ability (WISC--R)/achievement discrepancy test scores. The sample was of low average intellectual ability according to the WISC--R and the Luria-Nebraska T-scores. Intercorrelations between scores on the WISC--R and Luria-Nebraska lists were generally nonsignificant, with the exception of language and arithmetic measures on each test. Also, 84% or 27 of the present sample of 32 were correctly identified as learning disabled using a criterion of three or more Luria-Nebraska subscale scores greater than one SD above the mean.     

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.     

A comparison of methods for calculating a severe discrepancy

Given the substantial rise in the number of students identified as learning-disabled, increasing attention has centered on methods for determining a severe discrepancy between ability and achievement. Using scores from 86 learning disabilities referrals, we compared four such methods (a z-score discrepancy, an estimated true score discrepancy, an unadjusted regression procedure, and an adjusted regression procedure). Each student was evaluated with the WISC-R, PIAT, and K-ABC. A high degree of agreement was found between z-score and estimated true score difference approaches. Less agreement was found between the unadjusted regression procedure and the other methods. It was concluded that the four methods cannot be used interchangeably in the calculation of severe discrepancies. Of the four methods that were analyzed, the unadjusted regression procedure selected the smallest percentage of students.     

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.