Wechsler Preschool and Primary Scale of Intelligence

The Wechsler Preschool and Primary Scale of Intelligence (WPPSI) is an intelligence test designed for children ages 2 years 6 months to 7 years 7 months developed by David Wechsler in 1967. It is a descendent of the earlier Wechsler Adult Intelligence Scale and the Wechsler Intelligence Scale for Children tests. Since its original publication the WPPSI has been revised three times in 1989, 2002, (followed by the UK version in 2003) and 2012. The current version, WPPSI–IV, published by Pearson Education, is a revision of the WPPSI-R (Wechsler, 1989) and the WPPSI-III (Wechsler, 2002). It provides subtest and composite scores that represent intellectual functioning in verbal and performance cognitive domains, as well as providing a composite score that represents a child’s general intellectual ability (i.e., Full Scale IQ).

The original WPPSI (Wechsler, 1967) was developed as an intelligence measure for 4-6:6yr olds in response to an increasing need for the assessment of preschoolers. The WPPSI was divided into eleven subtests, all of which were retained in the revision in 1989. The WPPSI-R expanded the age range to 3–7 years 3 months and introduced a new subtest, Object Assembly. WPPSI-III incorporates a number of significant changes. Additional subtests have been designed to enhance the measurement of Fluid Reasoning (see Carroll, 1997) these are; Matrix Reasoning, Picture Concepts and Word Reasoning. Measures of Processing Speed have also been taken from the WISC-III, adapted for use with younger children and included as new subtests (Coding & Symbol Search). The age range has been lowered to 2 years 6 months, and has also been divided into two bands: 2 years 6 months - 3 years 11 months and 4–7 years 3 months, this was done in recognition of the substantial changes in cognitive development that occur during early childhood. The WPPSI-IV added the new Working Memory subtests of Picture Memory and Bug Search and the new Processing Speed subtests of Bug Search, Animal Coding, and Cancellation. It also simplified and shortened instructions.

The Wechsler Preschool and Primary Scale of Intelligence consist of 14 subtests. They are designated as one of three types: core, supplemental, or optional. The core subtests are required for the computation of the Verbal, Performance, and Full Scale IQ. The supplemental subtests provide additional information about cognitive abilities or can be used as replacement for inappropriate subtests. The optional subtests provide additional information about cognitive functioning but cannot be used as replacements for core subtests.

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