A longitudinal comparison of the WISC and WISC-R with special education pupils

The purpose of this study was to determine the degree of comparability between the WISC and the WISC-R over time. Hypotheses were tested using a sample of 276 mildly mentally handicapped children enrolled in special education classes who had received a WISC (Trial 1) and a WISC or WISC-R (Trial 2) after an interval of approximately three years. The sample was grouped on the basis of test administered in Trial 2. Group I contained those children who received the WISC on Trial 2 and included 183 children, of whom 121 were males and 62 were females. Mean age at time of initial testing was 8–10; mean age at second testing was 11–8. Group II was composed of 93 children who had been posttested on the WISC-R and included 72 males and 21 females. Mean age at initial testing was 9–5; mean age at posttest was 13–0. The study was conducted in five school districts and one county department of education. Verbal IQ, Performance IQ, and Full Scale IQ for both instruments administered were transcribed from the special education folders of the children. The design used to test hypotheses was repeated measures analysis of variance. Data analysis resulted in rejection of the hypotheses that the WISC-R yields mean Verbal, Performance, and Full Scale IQ scores greater than or equal to the corresponding mean IQ scores of the WISC. It was concluded that the WISC-R may unfairly penalize special education children who are reevaluated with this instrument. Fluctuations in IQ scores due to the instrument of measurement must be recognized, and appropriate action should be taken to insure that children are evaluated for special class placement on comparable bases.     

Comparison of bilingual children on the WISC-R and the Escala de Inteligencia Wechsler Para Ninos

A comparison was made of bilingual Puerto Rican students' scores on the WISC-R and the Escala de Inteligencia Wechsler Para Ninos to see whether there were any differences in scores based on the language in which they were tested. These children were determined to be equally proficient in English and Spanish, based on scores from the Dailey Language Facility Test. There were no significant differences between the Full Scale and the Verbal Scale scores on both tests, but significant differences were found between the Verbal and Performance Scale scores on both tests. Caution in testing bilingual children before determination of bilinguality, as well as further research into development of intelligence tests for individual culture groups, is recommended.     

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.     

A comparison of WISC and WISC-R results of urban educable mentally retarded students

Twenty urban EMR students' WISC-R scores were compared with their previously administered WISC scores. The average interval between administrations was approximately three years. Significant coefficients of correlation were obtained between five corresponding subtests and between Performance IQs and Full Scale IQs. Results from t tests for correlated data indicated that mean WISC-R Verbal, Performance, and Full Scale IQ scores were not significantly lower than their corresponding WISC scores. The results of this study indicated that WISC-R scores in comparison to WISC scores appeared to be more stable in the lower IQ ranges and less vulnerable to cultural bias.     

Stability of WISC-R scores in children with learning difficulties

Student records of 130 children with learning difficulties who had been tested twice were examined to determine the stability of WISC-R scores over time. There were significant losses in Verbal IQ and Full Scale IQ. Subjects in the above-average IQ range had greater losses in Verbal IQ and Full Scale IQ and greater gains in Performance IQ than did those in the below-average IQ range. Children initially tested before age 8 had a significant IQ loss, but those tested after age 8 maintained a constant IQ. The WISC-R is most frequently administered to children with learning difficulties. Results presented here suggest that the IQs in this population are not as stable as was previously thought, and this may provide a rationale for the periodic readministration of the WISC-R.     

Validation of the Stanford-Binet Intelligence Scale: Fourth edition with exceptional black male students

Standard Age Scores on the Stanford-Binet Intelligence Scale: Fourth Edition (SBIV) and WISC-R IQs of 51 urban black males receiving special education services were compared. Correlations between the SBIV Composite scores and WISC-R Verbal, Performance, and Full Scale IQs were 0.803, 0.826, and 0.87 respectively. Correlations between all combinations of scales ranged from 0.612 to 0.888, median r=.723. SBIV Composite mean scores did not differ significantly from the mean WISC-R Full Scale, Verbal, and Performance IQs. Regression analysis of the three subgroups (BD. LD, and EMR) indicated that the SBIV possesses differential validity for each group. Tabular comparison of precision of classification between the SBIV and the WISC-R yielded a 78% agreement. These data suggest that the SBIV possesses utility for assessing the intelligence of black students classified as BD and EMR. However, the use of the scale with LD students is unsupported.     

Screening for giftedness with the Slosson and the scale for rating behavioral characteristics of superior students

Children who had been nominated as potential candidates for gifted programs were assessed to determine the relationships among certain behavioral and intellectual characteristics. Records were compiled listing 132 first- through eighth-grade children's race, sex, age, grade level, Slosson Intelligence Test (SIT) IQ scores, Scale for Rating Behavioral Characteristics of Superior Students (SRBCSS) scores, and WISC-R IQs. Only children achieving SIT IQs of 130 or higher were included. A regression equation for the prediction of a WISC-R Full Scale IQ score from a given SIT score was computed and compared to that developed for predicting the WISC-R IQ in another study. All variables except SIT IQ were poor predictors of WISC-R IQ scores. A moderate correlation was computed between SIT and WISC-R Verbal and Full Scale IQ scores. A somewhat lower, but still significant, degree of relationship was found between SIT and WISC-R Performance IQ scores. Some difficulties with using the SIT as a screen for gifted programs are discussed.     

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.     

Predictive validity of the Slosson Intelligence Test with the WISC-R and the WRAT-R level 1

Slosson Intelligence Tests (SITS) administered by school guidance counselors correlated significantly with school psychologist administered WISC-Rs (r=.75). The Slosson IQ correlated significantly higher with the WISC-R Verbal IQ than with the Performance IQ score. The mean Slosson IQ was a statistically significant 4.4 points higher than the mean WISC-R Full Scale IQ (p<.01).     

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.     

Similarity of WISC-R and WAIS-R scores at age 16

Thirty learning disabled students of average intellectual ability between 16 and 17 years of age were given both the WISC-R and the WAIS-R to determine if the WAIS-R provided higher average IQ scores, as had been reported for educationally mentally retarded adolescents. The results indicated: (a) no significant differences between the two scales on either the Verbal, Performance, or Full Scale IQs, (b) significant correlations between the WISC-R and WAIS-R on the three IQ scores and 9 of the 11 subtests, and (c) the emergence of the ACID profile for learning disabled adolescents on both tests.     

Stability of WISC-R intelligence scores: Implications for 3-year reevaluations of learning disabled students

Student records of 170 learning disabled students from two area agencies were examined to determine the stability of WISC-R test scores administered as part of the 3-year reevaluation of students required by Public Law 94–142. The WISC-R had been readministered to 150 of these students. Stability coefficients were .72, .70, and .74 for the Verbal, Performance, and Full Scale IQ scores. Changes in Full Scale scores were 4 points or less for 52% of the sample. Changes greater than 15 points were noted for 4% of the sample. Results suggest that WISC-R scores are reasonably stable over a 3-year interval, and routine readministration of the WISC-R should not be required or encouraged.     

Comparison of the PPVT-R and WISC-R with urban educable mentally retarded students

Comparisons of the revised PPVT (PPVT-R) and the WISC-R were made with 67 EMR students. Significant differences were found between the PPVT-R mean standard scores and Verbal, Performance, and Full Scale IQs. The PPVT-R did not correlate significantly with the WISC-R scales or subtests, suggesting the tests are measuring different abilities.     

An epidemiologic approach to screening gifted students utilizing WISC-R subtests

Full WISC-R evaluations of students who are referred to a gifted program, but who do not meet placement criteria, have become a drain on the resources of many school districts. A screening formula for gifted students, utilizing three WISC-R subtests (VO-BD-SI), was evaluated using traditional epidemiologic techniques. The screen was applied to the records of 200 students who had been referred for a gifted program and received complete WISC-R batteries. Screen results were compared to actual placement of the 200 subjects based on a WISC-R Full Scale, Verbal, or Performance IQ of 130 or more. Measures of sensitivity, specificity, and predictive value of the screen were determined. The screen correctly detected the majority of gifted students and could have major implications in terms of cost effectiveness and professional time management.     

Relationship between PPVT and WISC-R in children with reading disabilities

The Peabody Picture Vocabulary Test (PPVT), Form A was compared to the Wechsler Intelligence Scale for Children-Revised (WISC-R) in two samples of children with reading disabilities. One group of 14 children, referred to a university clinic, were administered the WISC-R, followed by the PPVT. The second group of 38 children from a private learning disability center were administered the PPVT first, followed by the WISC-R. In the combined sample, the PPVT IQ (X̄ = 109.2) was significantly higher than the WISC-R Verbal IQ (X̄ = 98.9), Performance IQ (X̄ = 97.0), and Full Scale IQ (X̄ = 97.5). Similarly, the PPVT IQ was significantly higher than the WISC-R Full Scale in both samples separately, regardless of which test was administered first. In one case, the PPVT IQ was 50 points higher than the WISC-R IQ. Correlations between the PPVT and WISC-R Verbal, Performance, and Full Scale IQs were significant (rs = .56, .29, and .50, respectively). The results suggest that the two tests do not provide interchangeable IQs for a population of reading disabled children.     

Concurrent validity of the test of nonverbal intelligence with learning disabled children

Results of the TONI, WISC-R, and WRAT were compared for a sample of 66 learning disabled children: 51 males (32 white, 19 black) and 15 females (9 white, 6 black) whose mean age was 9–5 (SD = 1–10). The mean score of the TONI was significantly different from the Performance IQ. Nonsignificant differences were found between the TONI and Full Scale IQ and between the TONI and Verbal IQ. Correlation coefficients between the TONI and WISC-R ranged from a low of .35 for the Verbal IQ to .44 for both the Full Scale and Performance IQs. The correlation coefficients between the TONI and standard scores of the WRAT were .38, .27, and .23, for Reading, Spelling, and Arithmetic, respectively. Implications of these findings are 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.     

Comparability of the WISC and the WISC-R in normal children of divergent socioeconomic backgrounds

WISC and WISC-R IQs of two groups of normal ten-year-old children from divergent socioeconomic backgrounds (N = 36) were compared in a counterbalanced research design. Generally, all WISC mean IQs were higher than the WISC-R mean IQs for both groups of children. Significantly higher WISC IQs were obtained on the Verbal and Full Scales of the low socioeconomic group and on the Performance and Full Scales of the high socioeconomic group. Correlations between tests for Verbal, Performance, and Full Scale IQs were.95,.79, and.91 for the low socioeconomic group, and.84,.57, and.87 for the high socioeconomic group. Although practice effects did not appear to significantly affect IQs of the low socioeconomic group, various practice effects were observed in the high socioeconomic group. Negative effects were observed for both WISC and WISC-R on the Verbal Scale, whereas positive effects were observed on both Performance and Full Scales in this group. Analysis of simple effects reveals that WISC and WISC-R IQs did not differ significantly upon first administration, but were significantly different upon second administration. Conclusions were drawn that while WISC-R yields a lower IQ estimate than WISC for children of lower ability, results were not so clear for the children of higher ability, due to practice effects which disproportionately favor increases on WISC IQs upon second administration. The greater practice effects found on the WISC have implications for comparisons of the two tests in counterbalanced research designs. Simple randomized or treatment-by-levels design may be more useful in comparisons of the WISC and the WISC-R because of the bias introduced by counterbalanced designs.     

Comparison of scores for intellectually gifted students on the WISC-R and the fourth edition of the Stanford-Binet

The WISC-R and the Fourth Edition of the Stanford-Binet (SB: FE) were compared in the identification and assessment of 48 intellectually gifted students in the primary and secondary grades. While only a 3.2-point difference between the mean SB: FE Composite score and the mean WISC-R Full Scale score was found, (r = .393, p. ⩽ .01), the t test between the two scores was significant (t = 2.30, p ⩽ .05). Correlations between the three scales of the WISC-R and the SB: FE four broad area and Composite scores ranged from −.219 (SB: FE Abstract/Visual Reasoning with WISC-R Verbal) to .599 (SB: FE Short-Term Memory with WISC-R Full Scale). Within the correlational matrix, only 5 of the 15 correlations were significant. Both the SB: FE Abstract/Visual Reasoning and Quantitative Reasoning Area scores had no significant correlations with any of the WISC-R scores.     

Clinically and theoretically derived WISC-R subtest regroupings: Predicting academic achievement in a referral population

Attention continues to be directed toward the WISC-R as a tool for understanding children's learning problems. The formulation of WISC-R subtest regroupings (apart from the traditional Verbal, Performance, and Full Scale IQs, and the empirically derived factor scores) may provide a basis for score interpretation and the generation of hypotheses regarding children's cognitive strengths and weaknesses. The present investigation analyzed the predicitive utility of several WISC-R subtest recategorizations with regard to academic to achievement as measured by the WRAT. The sample consisted of 105 children who had been referred for psychoeducational evaluation because of classroom learning problems. Stepwise regression analyses indicated that many of the regroupings were significant predictors of academic achievement. Generated regression equations are presented.