The Wechsler Preschool and Primary Scale of Intelligence – 3rd Ed.

Friday, 25 April 2008 11:03

Mimi Wellisch (Registered Psychologist) provides an introduction to this common psychological test. The Wechsler Preschool and Primary Scale of Intelligence - Third Edition - Australian Standardised Edition (WPPSI-III Australian) is a revision of the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R) and assesses the intellectual ability of children aged 2 years 6 months to 7 years 3 months. The maximum Full Scale score that can be obtained with this test is IQ160.

The test is reflective of the developmental changes in young children, demonstrated through administration of subtests for two separate age-groups: For children aged 2:6 to 3:11 years, 4 core subtests are administered to obtain the Verbal, Performance and Full Scale IQs scores. Administration of the core subtests takes around 30-35 minutes. There are other subtests that can be added for additional information, for instance those that make up the General Language Composite, or they can be administered as an alternative to core subtests. If more subtests are administered, the administration time can be expected to increase. The core subtests for this age-group are:

Administration time for the 4:0-7:3 year olds’ 7 core subtests take around 40-50 minutes. Verbal, Performance, Processing Speed Quotient and Full Scale IQ scores can be obtained. Again, there are other subtests that can be added or used instead of the core subtests. If additional subtests are administered, the administration time would naturally increase. The following core subtests are administered to this age-group:

The Verbal score evaluates skills in understanding verbal information, thinking with words, and expressing thoughts as words. The Performance score examines ability to solve problems without using words, evaluating nonverbal problem solving, some eye-hand coordination assessment, how efficiently a child works with visual information. Processing Speed evaluates the ability to quickly scan symbols and make judgments about them.

A report will include a child’s scaled score, a test age equivalent and a percentile rank (see example of a Verbal subtest score summary below for a child aged 4:0 years). A scaled score is the mathematical transformation of a raw score to allow for a numerical comparison between children. The maximum Scaled Score possible is 19. A test age equivalent will also be given in a report. For instance, a 4:0 year old child may obtain a score in a particular subtest that places him or her at 5:4 years. Finnaly, the percentile rank shows the child’s rank in comparison with Australian children his or her own age. For instance, if the percentile rank were 80, it would mean that the child scored higher than approximately 80 out of 100 children his or her exact age.

It is important to keep in mind that this test measures intellectual ability, but does not measure other abilities such as creativity, leadership skills or musicality. It is also useful to know that children’s performance can be affected by their mood, level of energy and health on the day, or even their relationship with the psychologist administering the test.

Mimi Wellisch
Psychologist, NSW Reg. No. PS0085101, Associate Member APS
Grad.Dip Psych, Post Grad Dip. Psych.Dip.T. (E.C.), B.Ed (E.C.E), MECh (Macquarie)
Director, Clever Kids Consultancy, web address: www.cleverkidsconsultancy.com