Purpose: Designed as a comprehensive measure of cognitive ability for preschoolers.
Population: Ages 4.0-6.5.
Score: Verbal, Performance, and Full Scale IQS.
Time: (50-75) minutes.
Author: David Wechsler.
Publisher: The Psychological Corporation.
Description: The Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R) is one of the major instruments for assessing the cognitive ability of young children. Like its predecessor, the WPPSI-R is separate and distinct from, although similar in form and content to, the WISC-R.
Scoring: The WPPSI-R contains 12 subtests, 6 in the Performance Scale and 6 in the Verbal Scale. Five of the six subtests in each scale are designated as the standard subtests. They are Object Assembly, Geometric Design, Block Design, Mazes, and Picture Completion in the Performance Scale and Information, Comprehension, Arithmetic, Vocabulary, and Similarities in the Verbal Scale. The optional subtests are Animal Pegs in the Performance Scale and Sentences in the Verbal Scale. The WPPSI-R employs the Deviation IQ (M = 100, SD = 15) for the Verbal, Performance, and Full Scale IQS and scaled scores (M = 10, SD = 3) for the subtests. A raw score is first obtained on each subtest and then converted to a scaled score within the examinee's own age group through use of a table in the WPPSI-R manual.
Reliability: The WPPSI-R Performance, Verbal, and Full Scale IQS have excellent reliability in eight of the nine age groups covered by the test. From ages 3 through 6.5 years, the reliabilities for each of the three IQS range from .90 to .97. Across the nine age groups, the average internal consistency reliabilities are .92 for the Performance Scale IQ, .95 for the Verbal Scale IQ, and .96 for the Full Scale IQ. Test-retest reliabilities for a period of approximately 3 to 7 weeks for Performance, Verbal, and Full Scale IQS were .87, .89, and .91, respectively.
Validity: Reviewers note that because of the similarity of content, much of the research on the validity of the original WPPSI is pertinent to the WPPSI-R. These studies indicate that the WPPSI has adequate construct, concurrent, and predictive validity for many types of normal and handicapped children in the age range from 4 to 6.5 years.
Norms: The WPPSI-R was standardized on 1,700 children, 100 boys and 100 girls in each of eight age groups from 3 to 7 years and one group of 50 boys and 50 girls from 7 years. The 1986 U.S. census data were used to select representative children for the normative sample.
Suggested Uses: It is suggested that the WPPSI-R is an appropriate instrument for practitioners and clinical researchers in assessing children’s cognitive ability.