WPPSI Subtests Research Articles

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.

Preschoolers' Cognitive Performance Improves Following Massage*

Preschoolers (Mage = 4 years, 4 months) were given WPPSI subtests, including Block Design, Animal Pegs and Mazes, before and after receiving a 15‐minute massage or spending 15 minutes reading stories with an experimenter. Results revealed that performance on Block Design improved following massage and accuracy was greater on Animal Pegs in the massage group, particularly in more temperamental children. *This research was supported by an NIMH Research Scientist Award (#MH00331) and an NIMH Research Grant (#MH46586) to Tiffany Field and a grant from Johnson and Johnson to the Touch Research Institute. The authors wish to thank the children, parents and teachers for participating in this study. We also thank Claudia Thyssen and the volunteer massage therapists for helping with data collection.

Patterns and Prevalence of Core Profile Types in the Wppsi Standardization Sample

The most representative subtest profiles were found for the 1,200 children comprising the standardization sample of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI; Wechsler, 1967). The primary benefit of such a core profile typology is that it provides necessary contrasts for testing hypotheses about whether children’s profiles are descriptively or clinically unique. Scaled scores from WPPSI subtests were grouped according to similar level and shape using sequential minimum-variance cluster analysis with independent replications. A final solution of six core profile types met all formal heuristic and statistical criteria. Results are discussed in the context of leading research on the correlates of children’s abilities. Thereafter, two methods are presented for determining the relative uniqueness of WPPSI subtest patterns: the first is mathematically precise and the second is more convenient to every day practice. A step-by-step worksheet is provided for the “everyday” method and a case study is analyzed using this procedure.

A confirmatory maximum likelihood factor analysis of the WPPSI

A simultaneous confirmatory maximum likelihood factor analysis was conducted on the 11 subtests of the WPPSI in the 6 age groups in the normative sample. Four substantive models were fitted to the data and compared: (1) a single-factor model; (2) orthogonal and oblique 2-factor models, in which the 2 factors were composed of the Verbal and Performance subtests, respectively; (3) orthogonal and oblique 3-factor models, based on factor solutions for the WISC-R; and, (4) orthogonal and oblique 4-factor models, based on a Bannatyne recategorization of the WPPSI subtests. Results of these analyses indicate that: (1) the single-factor model fits the data quite well, though there is some mis-specification in this model; (2) the oblique 2-factor model does fit the data slightly better than the single-factor model; and, (3) the 3- and 4-factor models either produce improper parameter estimates or do not converge to a proper solution. It is concluded that the WPPSI largely reflects a general intellectual factor, and that any additional common ability factors play only a small role in determining WPPSI scores.

Infant assessments as predictors of 3-year IQ

Using 72 lower class children, concurrent validity of the WPPSI was studied employing Form L-M of the Stanford-Binet as the criterion. Correlations between SB and WPPSI were moderately high (.86 for FS, .81 for VS, .73 for PS), but the WPPSI appeared a somewhat more difficult test for the sample employed. Mean SB IQ (94.61) was higher than the mean FS (90.71), VS (89.38) and PS (93.68) IQs; it exceeded WPPSI IQ in 72% of all cases. On the WPPSI, PS IQ was significantly greater than either VS or FS IQs. Amont the WPPSI subtests, Vocabulary was significantly lower than all other subtests and Comprehension lower than Picture Completion, Mazes, and Block Design. The only significant sexual difference favored females on Similarities. For subjects whose FS IQ was below the group median IQ, relationships among each of the WPPSI scales and subtests were lower than for those subjects who scored above the median. This was particularly true for the Vocabulary, Animal House, and Picture Completion subtests.

A LONGITUDINAL STUDY USING THE WPPSI AND WISC‐R WITH AN ENGLISH SAMPLE

Summary. An unselected sample of 139 English children from a rural area completed the WPPSI at the age of 4½ years and the WISC‐R four years later. Comparison of WISC‐R results for this sample and Wechsler's standardisation sample indicated that although this test yields IQ scores close to expected values, distributions of scores on some subtests, especially Similarities and Coding, are less satisfactory. Significant sex differences, in keeping with previous research, were found on some WPPSI and WISC‐R subtests. The association between verbal‐performance discrepancies on the two tests was statistically significant but relatively weak. The results indicated that children who refused to co‐operate with one or more of the WPPSI subtests were more likely than not to develop normally, but there was a raised incidence of WISC‐R IQs below 85 in this group. A high proportion of low IQs was also found among children who missed the pre‐school assessment because of family crises or parental refusal.

THE FACTORIAL STRUCTURE OF WECHSLER'S PRESCHOOL AND PRIMARY SCALE OF INTELLIGENCE AT SUCCESSIVE AGE LEVELS

Summary. A factor analysis of the correlation matrix for the subtests of WPPSI was carried out for each of the age groups between 4 and 6½ years. The data were obtained from the WPPSI standardisation samples. In each analysis, three factors were extracted and two of these, after equimax rotation, were found to give patterns of loadings which were similar for all age groups. The rotated factors were identified as verbal intelligence, space performance and comprehension. Order analysis of the same data tended to support the notion that these factors could be also arranged into a circular order along with various tests of WPPSI. Using a likelihood ratio test for the Guttman ‘circumplex’ structure, the correlation matrix for the 4‐year age group was analysed and the result provides clear support for the postulated circular arrangement of the tests. The circumplex ordering of WPPSI suggests a systematic ordering according to the law of neighbouring variables and is found to be more parsimonious and less subjective in interpreting than the results emerging from the traditional factor analysis.

Patterns of Intellectual Ability in Jewish and Arab Children in Israel II

Following the finding (previously reported in JCCP) of a particular pattern of WPPSI subtests in samples drawn from children of Arab villages, we studied a sample of Arab city children. Arab and Jewish children living in a city in northern Israel were matched as closely as possible for school grade, age, and SES. The results indicated little if any difference between Jewish and Arab children in level or pattern of the intellectual abilities tapped by the WPPSI. It is thus suggested that the pattern difference previously found is not likely to be related to the Arab-Jewish ethnic difference per se, but probably reflects an interaction of ethnicity and subcultural environment.

Relationship of the Wechsler pre-school and primary scale of intelligence and the Stanford-Binet (L-M) in lower class children

Using 72 lower class children, concurrent validity of the WPPSI was studied employing Form L-M of the Stanford-Binet as the criterion. Correlations between SB and WPPSI were moderately high (.86 for FS, .81 for VS, .73 for PS), but the WPPSI appeared a somewhat more difficult test for the sample employed. Mean SB IQ (94.61) was higher than the mean FS (90.71), VS (89.38) and PS (93.68) IQs; it exceeded WPPSI IQ in 72% of all cases. On the WPPSI, PS IQ was significantly greater than either VS or FS IQs. Amont the WPPSI subtests, Vocabulary was significantly lower than all other subtests and Comprehension lower than Picture Completion, Mazes, and Block Design. The only significant sexual difference favored females on Similarities. For subjects whose FS IQ was below the group median IQ, relationships among each of the WPPSI scales and subtests were lower than for those subjects who scored above the median. This was particularly true for the Vocabulary, Animal House, and Picture Completion subtests.