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.     

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.     

A comparison of the criterion-related validity (academic achievement) of the WPPSI and the WISC-R

Correlations of WPPSI IQs with concurrently administered subtests from the WRAT were compared with analogous WISC-R/WRAT correlations in a group of children referred by regular classroom teachers for school psychological services. Although the magnitudes of all correlations were reduced, due to restriction of range, the comparisons indicated no significant differences in the magnitudes of the correlations of the WPPSI and the WISC-R with the WRAT. These results support the use of the two instruments as equivalent predictors of achievement.     

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.     

A longitudinal study of the Stanford-Binet and WISC-R with special education students

A group of 95 black and 52 white low socioeconimic children assigned to special education calsses were initially given the Stanford-Binet (1972 norms) and three years later the WISC-R. Correlations between the Stanford-Binet and WISC-R Full Scale IQs were significant in both ethnic groups, with r=.60 for the total group. Correlations between the Stanford-Binet and WISC-R subtests also were generally signiificant (rs between .29 and .52 for the total group). Stanford-Binet and WISC-R Full Scale IQs did not differ significantly. For this sample of special education children, the Stanford-Binet was found to have satisfactory predictive validity.     

A comparison of the WISC and WISC-R

So as to compare the results of the WISC and WISC-R, both instruments were administered to 58 children randomly selected from a school population of 583. All administration and scoring was performed by the same psychologist, with a two-month interval separating the administrations for each child. All IQs were significantly higher (p <.01) on the WISC, with the Performance difference being greater than the verbal difference. Also, 8 of the 10 required subtest scaled scores were significantly greater (p <.05) on the older instrument. Regression equations were obtained to predict WISC-R IQs from WISC scores.     

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.     

Predictors of ability-achievement discrepancies in children referred for psychoeducational evaluation

The present study evaluated a school district's psychoeducational screening program to determine the best predictors of two difference score variables: (a) WISC-R FSIQ – PIAT reading recognition score and (b) WISC-R FSIQ – PIAT math score. The study also investigated the merit of using scores from a group-administered achievement test (CAT) as predictors. Subjects were 61 first through fifth graders initially referred for testing from 1982–1984. Multiple regression analyses indicated: (a) for reading, the SIQ score and the PPVT-R – CAT reading difference score were significant predictors, together accounting for 27% of the variance, and (b) for math, the PPVT-R score accounted for 28% of the variance, with additional variables producing nonsignificant increments. Results suggest that CAT scores may prove useful predictors when combined with screening IQ tests to form difference scores.     

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.     

Correlations among the WISC-R,PIAT, and DAM

The WISC-R, PIAT, and DAM were examined to ascertain relationships among the three instruments. Moderate to high correlations were found when PIAT scores were compared to WISC-Rg iqs, while DAM standard scores correlated moderately with PIAT and WISC-R scores. Correlations indicate that information yielded by the PIAT may be obtained through WISC-R results, while the DAM may be tapping other abilities not adequately assessed by either of the other two measures.     

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.     

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.     

Investigations into the relationships of the WRAT,the PIAT,the SORT,and the WISC-R in low-functioning referrals

Research involving standardized reading achievement tests has been widespread, but there has been little investigation into the relationships among the more widely used tests of reading achievement. In the present study, the Reading subtest of the WRAT, the Reading Comprehension subtest of the PIAT, and the SORT were compared with each other and with the WISC-R. Results showed a high correlation between the WRAT and the PIAT, a moderately high correlation between the SORT and the PIAT, and a very low correlation between the SORT and the WRAT. The WRAT and the PIAT had higher correlations with the various components of the WISC-R than did the SORT. These findings imply that the WRAT and the PIAT measure essentially the same dimension of reading achievement, possibly verbal fluency, but that the SORT is measuring a different dimension, one that is also tapped to some extent by the PIAT.     

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.     

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.     

Use of an abbreviated version of the WISC-R with learning disabled children

The Wechsler Intelligence Scale for Children-Revised (WISC-R) was administered to 56 learning disabled children, using standard assessment procedures and format as outlined by Wechsler. Abbreviated IQ scores were then derived by applying the Kennedy-Elder formula, and equation that uses five WISC-R subtests with varied weightings. Comparisons between the standard IQ scores and the abbreviated IQ scores were evaluated. A Pearson product-moment correlation coefficient of .83 and a non-significant t-test between the mean IQs suggested the two scores were interchangeable. However, frequent IQ classification changes (23%) rendered the K-E format unacceptable for this population.     

A comparison of three screening tests and the WISC-R in special education evaluations

Eighty public school children referred for psychological assessment for potential special education placement were given the Slosson Intelligence Test, Peabody Picture Vocabulary Test, Developmental Test of Visual-Motor Integration, and Wechsler Intelligence Scale for Children—Revised. Correlational and regression techniques were used to determine the effectiveness of the three former measures in predicting WISC-R IQ scores. SIT IQs were found to be the best predictors of WISC-R Verbal, Performance, and Full Scale IQs; however, these statistical relationships reveal little about the clinical utility of the screening measures. Problems with use of the current findings and those of other studies are discussed.     

A comparison of the peabody individual achievement test,the metropolitan achievement test,and the otis-lennon mental ability test

In order to clarify the concurrent validity of the Peabody Individual Achievement Test (PIAT) and the Metropolitan Achievement Test (MAT), product-moment correlations were computed for all subscores and total scores for 26 normal-range public school third-grade girls and boys. The reading comprehension subtests correlated.81, spelling.88, and PIAT Mathematics with MAT Total Math.64. Correlations were computed for the Otis-Lennon Mental Ability Test and the PIAT General Information subtest as.77, and the Otis-Lennon and the PIAT Total Test scores as.79. Concurrent validity of the PIAT with both tests is tentatively considered adequate except in the area of mathematics, in which the PIAT, relative to the MAT, appears to be reflecting ability to handle math concepts (.68) more accurately than math computation (.41) or math problem solving (.56). Correlations with IQ partialed out suggest the PIAT Total Test, and PIAT and MAT reading and spelling measures, are relatively uninfluenced by IQ variations, whereas with IQ held constant, the weak positive correlations between the PIAT and MAT math subtests became essentially random relationships.     

Suitability of the California Abbreviated WISC for WISC-R subtests with mentally retarded and slow learner children

This study was undertaken to determine the suitability of the California Abbreviated WISC—Form 1 (CAW-1) for use with WISC-R subtests. Subjects were drawn from the files of previously evaluated students from two southern mountain communities. Examination of WISC records within the age and IQ ranges of the CAW-1 (CA 8-0 to 13-6, IQ 50 to 80) indicated that our sample was not significantly different from the CAW-1 noim group (N = 148, r = .85 between CAW-1 & WISC Full Scale IQ). WISC-R recods (N = 178) for the same ranges were examined and were found to be more highly predictive of Full Scale IQs (r = .91, FSIQ = .98 CAWIQ + 2.2). Extensions of the age range from 6-0 to 16-11 and of the IQ range from 40 to 100 were attempted. Final results (N = 284) indicated the CAW-1 could be used with the WISC-R over the full age range and for IQs ⩽ 100 with minor alteration (r = .96, FSIQ = 1.09 CAWIQ - 5.4). The second sample served for cross validation of these results. Using the alteration, results were consistent with original findings (N = 202, r = .93, FSIQ = .98 CAWIQ + 2.2). It was concluded that the CAW-1 was suitable for use with WISC-R subtests with minor alterations.     

Normative achievement assessment of gifted children: Comparing the K-ABC,WRAT, and CAT

The Kaufman Assessment Battery for Children (K-ABC) purports to assess fluid and crystallized intelligence via processing and achievement subtests, respectively. Eight K-ABC Mental Processing and five K-ABC Achievement subtests were administered to 41 gifted students. Scores were subsequently compared to concurrent achievement measures from the California Achievement Test (CAT), as well as previously obtained mental ability measures (Wechsler Intelligence Scale for Children-Revised [WISC-R], Stanford-Binet [SB], and Wide Range Achievement Test [WRAT] achievement scores). In general, K-ABC mental ability scores were lower than WISC-R and SB IQs. K-ABC achievement scores were consistent with K-ABC mental ability scores, but more highly related to SB and WISC-R VIQ (r = .42 and .40, respectively) than to WISC-R FSIQ (r = .16) and PIQ (r = .09), or to the K-ABC Mental Processing (Composite r = .17), Simultaneous Processing (r = .08), and Sequential Processing scores (r = .20). With the exception of WRAT Word Recognition, WRAT, K-ABC, and CAT achievement scores were similar. The patterns of intercorrelations suggest that the K-ABC achievement scores are more verbally loaded than are the CAT and WRAT achievement measures.