WISC-R patterns for learning disabled children at three SES levels

WISC-R and socioeconomic status (SES) data were collected on 122 learning disabled (LD) children who had been assigned to self-contained LD classrooms. The children were divided into three groups on the basis of family SES: high, middle, and low. Three questions were explored: (a) Is there a relationship between SES and IQ test scores among LD-labeled children? (b) Is the pattern of subtest scores independent of SES level? (c) Is the Verbal-Performance IQ test score discrepancy independent of SES level? Results supported affirmative answers to all three questions. Discussion centered around the implications of these results for future research on the utility of the WISC-R for diagnostic purposes.     

Factor analysis of WISC-R scores for children identified as learning disabled,educable mentally impaired,and emotionally impaired

The WISC-R scores for groups of children identified by school personnel as needing special education services were factor analyzed according to type of classification. WISC-R factor loadings were obtained for the scores of children labeled Learning Disabled, Educable Mentally Impaired, and Emotionally Impaired, as well as groups labeled Other and None. Overall, results show the WISC-R to be factorially similar for all groups, with two principal factors emerging which correspond to the Verbal-Performance structure of the test. Significance tests among mean scale scores and IQ scores yielded few meaningful differences across groups.     

Scatter on the WISC as an indicator of intellectual potential

The study was undertaken to investigate the relationship between subtest scatter on the WISC and higher intellectual potential. All subjects at one time obtained Full Scale IQ scores within the retarded range. Group I consisted of those children who upon reexamination with the WISC obtained Full Scale IQ scores of 75 or below, while Group 2 consisted of those children whose Full Scale IQ scores were now found to be nonretarded upon reexamination. The results indicated that the scatter on the initial examinations failed to predict the future group membership. Irrespective of group membership, scatter was found not to be related to change in Full Scale IQ scores. It was concluded that subtest scatter is a poor indicator of the presence of higher intellectual potential. It was also suggested that these findings are relevant to the WISC-R.     

The role of sex differences in the referral process as measured by the Peabody Picture Vocabulary Test-Revised and the Wechsler Intelligence Scale for Children-Revised

The Peabody Picture Vocabulary Test-Revised (PPVT-R) and the Wechsler Intelligence Scale for Children-Revised (WISC-R) are two tests that are often used in the assessment process for special education referrals. Sex differences apparent in these tests were examined in a sample of Arkansas school children who were first-time referrals for a psychological evaluation. The subjects' PPVT-R standard scores, WISC-R IQ scores, and WISC-R subtest scores were divided into groups according to one-year intervals from ages 6 through 16. A separate 2 × 11 (subjects' sex x subjects' age) analysis of variance was performed for each dependent variable. Results indicated significant sex differences among WISC-R Full Scale, Verbal, and Performance IQs and PPVT-R standard scores (p < .01). Several WISC-R subtests also revealed significant sex differences. Further significant sex differences were indicated at several age groups on each dependent variable, with males consistently scoring higher than females on 87%. of the dependent measures excluding the WISC-R subtest Coding, on which females scored higher. Implications concerning the referral process are discussed.     

Subtest scatter and Kaufman regroupings on the WISC-R in non-learning-disabled and learning-disabled children

The present study was undertaken to examine scatter analysis and Kaufman regroupings of WISC-R scores. Thirty-one non-learning-disabled children (NLD) and 29 learning-disabled children (LD) determined by individual IQ and achievement scores served as subjects. Scatter indices were computed within the Verbal and Performance subtests as well as between the Verbal and Performance IQ scales. Also, the regrouping categories proposed by Kaufman (1979) were examined. A significant difference in Verbal and Performance IQs was found between the LD and NLD group. Significantly more students in the LD group exhibited the Kaufman regrouping pattern than in the NLD group (p < .01). These results suggest that Kaufman regroupings and Verbal-Performance scatter analysis may be used to assist in diagnosing LD children.     

Use of the WISC-R and K-ABC with learning disabled,borderline mentally retarded,and normal children

The aim of this investigation was to examine normal (N = 34), learning disabled (N = 34), and borderline mentally retarded (N = 33) children's performance on the WISC-R and K-ABC. Results revealed no significant differences between the WISC-R Full Scale IQ and K-ABC Mental Processing Composite by group (F = 0.7, p > .15). The Full Scale IQ and Mental Processing Composite standard score correlated .85 for the entire sample, and all other subscale correlations ranged from .65 to .90 (all significant at p < .001). Analysis of Verbal-Performance, Mental Processing-Achievement, and Simultaneous-Sequential discrepancy means by group revealed no significant differences in comparison to normative values. Subtest patterns analysis revealed high rank order correlations between the learning disabled and mentally retarded groups, but lower correlations between the exceptional and normal groups. Implications of these findings are discussed.     

Interpreting WISC-R and McCarthy scatter: A caution

In this investigation, indices of scatter on the WISC-R and McCarthy Scales were examined for 20 educable mentally retarded and 20 learning disabled children in relation to a similar control group. The scatter found in the two exceptional samples was also compared to the variability found in the standardization samples of the WISC-R and McCarthy. Results indicated that the learning-disabled sample exhibited more WISC-R subtest scatter and McCarthy Scale variability than the standardization sample but not more than the control group. The implications of these findings are discussed.     

Statistical and individual temporal stability of the WISC-R for cognitively disabled adolescents

This study examines the temporal stability of the WISC-R for 155 13-and 14-year-old adolescents identified as either EMR or LD who were involved in special education during the preceding three-year time period. The three major scales of the WISC-R were found to be more stable over a three-year period for the LD than for the EMR group, while the subtest scales for the EMR group, showed greater stability over the three-year interval. Test-retest coefficients for the EMR group were substantially lower than those presented in the WISC-R test manual. A large proportion of individuals within both groups showed statistically significant differences on one or more of the IQ score scales between testings based on standard errors of measurement. These findings are examined in relation to individual placement of students, reporting confidence intervals in reports, and calculation of the best unbiased estimate of intellectual functioning.     

Sex differences on the WISC-R for retarded children and youth

This study investigated sex differences on the WISC-R subtests for retarded males and females who were matched in terms of WISC-R Full Scale IQs. The sample consisted of 126 children and youth (63 females, 63 males) ranging in chronological age from 7–3 to 8–3, with a mean CA of 7–8. Each subject was matched in terms of Full Scale IQ score. A 2 × 10 analysis of variance with repeated measures on a single factor was used to analyze the data. Students' T and Fisher's F ratios were calculated, and differences between subtest means were analyzed by Newman-Keuls test for sample effects. Evidence from the investigation indicated that a significant interaction effect existed between sex and subtest scores.     

Stability of WISC-R subtest profiles for learning disabled children

Stability of the WISC-R subtest profile for 161 learning disabled (LD) children over a 7-month test-retest interval was examined. A unique subtest profile reported earlier (Smith, Coleman, Dokecki, & Davis, 1977a) was replicated. Performance IQ was significantly greater than Verbal IQ at both testing occasions. A mean test-retest increase was observed for Performance IQ, but not for Verbal IQ.     

Diagnostic utility of the K-ABC and WISC-R/PIAT in determining severe discrepancy

The basic question addressed in this study was whether the discrepancies found between the Mental Processing Composite (ability component) and the Achievement subtests of the Kaufman Assessment Battery for Children (K-ABC) corresponded with the discrepancies found between the WISC-R Full Scale IQ and the PIAT subtests, or whether use of the K-ABC over the WISC-R and PIAT results in the identification of different students. The differences were evaluated using four standard score procedures for calculating a severe discrepancy. It was found that the K-ABC and WISC-R/PIAT approaches to the determination of a score difference resulted in the identification of different populations of students. The high average PIAT standard scores together with the lower subtest reliabilities appeared to be the primary source of disparity between the K-ABC and WISC-R/PIAT comparisons.     

An investigation of WISC-R verbal-performance differences as a function of ethnic status

The Wechsler Intelligence Scale for Children-Revised was administered to 187 black, 184 Hispanic, and 184 white children aged 6–11. The Verbal-Performance (V-P) IQ discrepancies were determined for the total group and for each ethnic group. The overall mean of 10.74 was similar to the V-P discrepancy found in the WISC-R standardization sample. The Hispanic group had a significantly greater V-P split than did the black group or the white group. Implications of these results were discussed, focusing on the various cautions of using V-P discrepancies for diagnostic decision making.     

Relationship between WISC-R and WRAT in children referred for learning difficulties

Correlations between the WISC-R Full, Verbal, Performance, and Freedom from Distractibility Scale IQs, WISC-R subtest scaled scores, and Wide Range Achievement Test Reading, Spelling, and Arithmetic standard scores were computed for a sample of 114 children (64 boys, 50 girls), aged 6 to 16 years, who were referred for psychological evaluation because of academic or learning difficulties. The Full Scale IQ, Verbal Scale IQ, and Freedom from Distractibility IQ correlated moderately with the three achievement area standard scores (rs of .48 to .59). However, the Performance Scale IQ correlated minimally with reading and spelling scores (rs of .26 and .27), but moderately with arithmetic scores (r = .40). The results support the concurrent validity of the WISC-R.     

The reliability of the WISC-R performance scale with deaf children

Though the Wechsler tests are widely used to assess the intellectual ability of hearing impaired children, data on the reliability of the WISC-R with this population have been lacking. The Performance Scale of the WISC-R was administered to 59 prelingually deaf children attending a state-supported day school program. The reliability coefficients and standard errors of measurement were computed for each subtest and for the Performance Scale IQ. The results compare favorably with those found by Wechsler with the standardization sample.     

Recategorized WISC-R scores of learning disabled children and differential diagnosis

This study analyzed WISC-R profiles along a three-factor approach (Spatial; Verbal-Comprehensive; Attention-Concentration), as suggested by Bannatyne (1968) for purposes of differential diagnosis. The WISC-R profiles of 278 school-verified learning disabled children were compared to those of four other groups: Educable Mentally Impaired (N = 141), Emotionally Impaired (N = 67), Otherwise Impaired (N = 61), and Nonimpaired (N = 294). The total sample was drawn from the State of Michigan public schools. Statistically significant differences were found between the learning disabled group and the other four groups on WISC-R subtest scores. Further analysis revealed that 36% of the learning disabled and 32% of normal children exhibited this WISC-R profile. Analysis of WISC-R profiles of Spatial→Verbal→Attention was not useful in differential diagnosis among the five groups. The results are discussed in terms of the limited utility of a three-factor analysis of WISC-R subtest scores for the purpose of differential diagnosis.     

Correlations between the Woodcock-Johnson and the WISC-R for a behavior disordered population

Correlations between the Woodcock-Johnson Test of Cognitive Abilities (WJTCA) and the Wechsler Intelligence Scale for Children-Revised (WISC-R) were evaluated on a sample of 55 behavior disordered males, 28 of whom were also diagnosed as learning disabled. Concurrent validity for this sample was demonstrated by only a 2.33 point difference between the mean WJTCA Broad Cognitive score and the mean WISC-R Full Scale IQ score. Analysis of Pearson product-moment correlations between each WISC-R subtest and each Woodcock-Johnson cluster score substantiated previous assertions that the WJTCA is unduly weighted with Product-Dominant factors. Construct validity of some of the WJTCA clusters also was questioned. Implications of these results for behavior disordered populations were discussed.     

Correlations between WISC-R subtests and verbal,performance, and full scale IQ scores for minority group children

The relationship between WISC-R subtest scores and Verbal, Performance, and Full Scale IQs was investigated for a sample comprised of rural Appalachian children. The sample was comprised of both white and black children who might be described as culturally different by virtue of low family income and residence in the mountainous areas of Virginia and North Carolina. Data analysis consisted of computing product-moment correlations (rs) between each of the ten subtests and the Verbal, Performance, and Full Scale IQs. Correlations between individual subtests and the FS IQ ranged from.49 through.63, but none of the differences between these rs were large enough to attain significance. Correlations between the verbal subtests and Verbal IQ ranged from.64 for Comprehension up to.78 for Vocabulary. For the performance subtest, the rs ranged from.54 between Coding and the Performance IQ up to.72 for Object Assembly.     

A comparison between the WISC and WISC-R among educable mentally retarded students

The study compared differences and similarities between WISC and WISC-R scores for 48 ten- and thirteen-year-old EMR students, who were matched according to sex and race. The WISC-R yielded significantly lower VS, PS, and FS IQ scores than the WISC for this predominantly rural Georgia population. The FS IQ scores from the WISC-R averaged 7.5 points lower than the WISC FS IQs, with similar differences noted for VS and PS scores. There was no significant difference in FS IQs between the two age groups. Results suggest that many children classified as “Borderline” or slightly above by the WISC will be classified as “Mentally Deficient” by the WISC-R.     

The use of Wechsler Scales in the assessment of Native Americans of the Columbia River Basin

Native American secondary students from the Columbia Basin were found to have significant Verbal-Performance discrepancies on the WISC-R and WAIS. Mean Verbal scores were significantly below the normative mean, while Performance scores were at, or above, the normative means. These findings substantiated research with other Native American groups. Also, the Verbal and Performance scales correlated so low as to preclude the Full Scale from being an accurate representation of the “g” factor of intelligence. Further, the predictive validity of the WISC-R and the WAIS for reading and math achievement was found to be at variance with the standardization group.     

Determining basals for the peabody individual achievement test

The appropriateness of the starting points for PIAT subtests as suggested by the test authors was investigated. For a sample of 113 subjects with an average WISC-R Full Scale IQ of 98, there was an average difference of nearly 8 points between the suggested starting points for the Mathematics subtest and the actual basals. The difference between suggested starting points and basals for the other subtests ranged from 8 to 12 points. It was suggested that the PIAT user start each subtest approximately 8 items below that suggested by the Manual.