WPPSI reliability and predictive validity with disadvantaged Mexican-American children

The reliability and predictive validity of the WPPSI was investigated with a sample of lower SES Mexican-American children. Reliability was determined using split-half procedures parallel to those reported in the test manual. Predictive validity was determined by correlating WPPSI scores with scores from the Metropolitan Reading Test. The results revealed that the WPPSI has high reliability, as determined by internal consistency procedures, but validity coefficients were not significant. These results suggest that the WPPSI may be inappropriate for special program placement purposes with this population.     

Long-term predictive validity of the WPPSI: An 11-year follow-up study

As part of a longitudinal study, a control group of 85 children were tested on the WPPSI at 5$\text{1}\text{2}$ years and the WISC-R at 16$\text{1}\text{2}$ years. Educational attainment was also assessed in adolescence. Data are presented illustrating the long-term predictive validity of the WPPSI. The Full Scale IQs on the two tests intercorrelated +0.86.     

Reliability and predictive validity of the WISC-R with native-American Navajos

The reliability and predictive validity of the WISC-R was examined with a sample of 40 Navajo children. Internal consistency reliability estimates of WISC-R subtests as well as composites were found to be low for the Navajo subjects as compared with the reliability coefficients reported in the WISC-R manual. Correlation coefficients between the WISC-R subtests and those of the Wide Range Achievement Test (WRAT) were low. Only the Block Design subtest correlated significantly with the WRAT-Spelling. The predictive validity of the WISC-R IQ scales was similarly found to be very low. Considering the nature and size of sample, cautions in generalizing these findings to other native-American populations are recommended.     

Predictive validity of the WISC-R with Mexican-American children

The reliability and predictive validity of the WISC-R was investigated with 46 Mexican-American children. Approximately a year and a half after the administration of the WISC-R, scores on the Iowa Tests of Basic Skills (ITBS) were collected. Internal consistency estimates for WISC-R subtests and composites were found to be comparable to those reported in the WISC-R manual. Correlations between WISC-R subtests and those of the ITBS ranged from modest for verbal subtests to mild when performance subtests were used as predictors. The best single predictor proved to be that of Verbal IQ, which accounted for some 40% of the variance in future achievement when measured by the ITBS. It was concluded that the WISC-R meets minimum requirements of reliability and predictive validity with Mexican-American children.     

Non-equivalence of WPPSI,WPPSI-R,and WISC-R scores

The WPPSI-R, WISC-R, and WPPSI were administered in a counterbalanced design to 72 children, between the ages of 5 years, 11 months and 6 years, 8 months, in order to determine their equivalence by testing the equality of means, variances, and covariances based on scaled scores and IQs. The results indicated that the three scales were not equivalent with respect to any of the IQs because they did not meet one or more of the criteria. The relative magnitudes of the mean IQs on the three scales were in accord with the predicted order: highest IQs on WPPSI, next highest on WISC-R, and the lowest on WPPSI-R. Results were discussed in the context of the secular inflation in IQs and the corresponding compensatory deflation built into the normative data of the new versions.     

Non-equivalence of WPPSI, WPPSI-R, and WISC-R scores

The WPPSI-R, WISC-R, and WPPSI were administered in a counterbalanced design to 72 children, between the ages of 5 years, 11 months and 6 years, 8 months, in order to determine their equivalence by testing the equality of means, variances, and covariances based on scaled scores and IQs. The results indicated that the three scales were not equivalent with respect to any of the IQs because they did not meet one or more of the criteria. The relative magnitudes of the mean IQs on the three scales were in accord with the predicted order: highest IQs on WPPSI, next highest on WISC-R, and the lowest on WPPSI-R. Results were discussed in the context of the secular inflation in IQs and the corresponding compensatory deflation built into the normative data of the new versions.     

Gender differences on the WPPSI, the WISC-R, and the WPPSI-R

The WPPSI, WISC-R, and WPPSI-R were administered in a counterbalanced design to 72 children between the ages of 5 years, 10 months, 16 days, and 6 years, 7 months, and 15 days to test the hypothesis that mean verbal IQs on these scales would be higher for boys than for girls. Results indicated that the mean verbal IQs for boys were significantly (p<.05) higher than those for girls on all three scales. Also, significant (p<.05) differences favoring boys were found onVocabulary andComprehension subtests on all three scales. These differences are probably a peculiarity of these scales and may not need any elaborate theoretical explanation. However, clinical uses of verbal and performance IQ discrepancies may not justifiably ignore the examinees’ gender.     

Gender differences on the WPPSI,the WISC-R,and the WPPSI-R

The WPPSI, WISC-R, and WPPSI-R were administered in a counterbalanced design to 72 children between the ages of 5 years, 10 months, 16 days, and 6 years, 7 months, and 15 days to test the hypothesis that mean verbal IQs on these scales would be higher for boys than for girls. Results indicated that the mean verbal IQs for boys were significantly (p<.05) higher than those for girls on all three scales. Also, significant (p<.05) differences favoring boys were found onVocabulary andComprehension subtests on all three scales. These differences are probably a peculiarity of these scales and may not need any elaborate theoretical explanation. However, clinical uses of verbal and performance IQ discrepancies may not justifiably ignore the examinees’ gender.     

A validity study of the K-ABC, the WISC-R, and the Stanford-Binet with nonreferred children

The Kaufman Assessment Battery for Children (K-ABC) is an attempt at improving assessment procedures related to the construct of intelligence. This study reports findings about the relationship between the K-ABC, the WISC-R, and the Stanford-Binet for 40 children with no known impairments serving as subjects. The intercorrelations of the K-ABC Mental Processing Composite with the WISC-R and with the Binet were .79 and .61, respectively. The overall results suggested some support for the use of the K-ABC as a measure of intelligence.     

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.     

Concurrent validity of the WISC-R factor scores

This study investigated the efficacy of predicting academic achievement as measured by the Wide Range Achievement Test using the factor scores of the Wechsler Intelligence Scale for Children-Revised as potential predictors. Both instruments were administered to 200 school children referred for psychological evaluations. Factor scores for the WISC-R were computed according to equations provided by Gutkin (1978). These factor scores then were regressed in a stepwise manner on the Reading, Spelling, and Arithmetic standard scores from the Wide Range Achievement Test. Stepwise regressions also were performed using the traditional Verbal and Performance IQs as the potential predictors. A comparison was made between the results obtained by use of the factors or the more common scores. The results indicated that the Freedom From Distractibility factor score significantly aided in the prediction of Reading and Spelling achievement and was of primary importance in predicting Arithmetic achievement. When the stepwise results using the different scores were contrasted, the factor scores accounted for appreaciably more variance in Arithmetic than did the traditional Verbal and Performance IQs. Derived regression equations are reported along with a discussion of the interpretability of the Freedom From Distractibility factor.     

Comparison of WISC and WISC-R scores of referred black,white and Latino children

Seventy-two school psychologists in the tri-state area of Michigan, Illinois and Ohio administered both the WISC and WISC-R to 164 black, white and Latino children in a counterbalanced order with a specific test-retest interval of not less than a week or more than a month. These children had been referred to the school psychologist because of concerns about their intellectual ability. Significant WISC/WISC-R differences were found, with the WISC-R yielding lower results. These results have implications for test users, special education programs, and mainstreaming efforts.     

Comparability of the WISC and WISC-R with bright elementary school students

The 50 subjects had met initial screening criteria for eligibility in a special program for the intellectually gifted. These 50, enrolled in grades 3 through 5 in Broward County, Florida, public schools, were next given the WISC and WISC-R, in a counterbalanced order: half were administered the WISC first; the other half was administered the WISC-R first. The test-retest interval was approximately 9 months. Higher mean IQ scores were obtained by the total group on the WISC as compared to WISC-R. However, the results showed that when the WISC-R was administered first, subsequent student WISC performance was significantly higher on all scales. No significant performance increase was obtained on the WISC-R when the WISC was administered initially. The results indicated that the WISC-R had a facilitative effect on the WISC, and that this effect did not appear when the order of administration was WISC-WISC-R. Quite conceivably, several differences in the instructions for administration of the WISC and the WISC-R enhanced the practice effect of initial WISC-R experience as opposed to initial WISC experience.     

Joint factor analysis of the K-ABC and WISC-R with normal children

This study investigated the factor structure of the WISC-R and K-ABC for a group of 212 normal children who were tested on both instruments in counterbalanced fashion. Separate factor analyses and a joint analysis consistently produced three factors. The various analyses led to the conclusion that there is a clear-cut correspondence between the WISC-R and K-ABC factors. WISC-R Verbal Comprehension corresponded closely to K-ABC Achievement; WISC-R Perceptual Organization resembled K-ABC Simultaneous Processing; and WISC-R Freedom From Distractibility was similar to K-ABC Sequential Processing. The g factors from both instruments also correlated substantially.     

Confirmatory factor analysis of the WPPSI for language-impaired children

The present study used a maximum-likelihood confirmatory factor analysis (CFA) to test the hypothesis that a four-factor model is the most parsimonious explanation of the structure of the WPPSI for language-impaired children. Four separate maximum-likelihood confirmatory factor analyses were performed on a sample of 198 Norwegian language-impaired children tested with the WPPSI, and on the Norwegian (n = 563) and American (n = 1200) standardization samples. A one-factor (general), a two-factor (verbal and performance), three-factor (parallel to the WISC-R) and a four-factor solution composed of "processing dependent" ("knowing how" and "seeing how") and "knowledge dependent" ("knowing that" and "seeing that") were imposed on the average intercorrelation matrices of the 11 WPPSI subtests. Confirmatory factor analysis indicated that the four-factor latent construct model was the most parsimonious explanation of the structure of the WPPSI for language-impaired children, as well as for normally developing children.