Early Childhood Measurement and Evaluation

Tool Review
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Early Childhood Measurement Tool Reviews as a resource for those who conduct screening,
assessment, and evaluation. To learn more about ECME and CUP, provide feedback, or to
access additional reviews, visit our website at www.cup.ualberta.ca or email us at
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Wechsler Preschool and Primary Scale of

Intelligence Third Edition [Canadian] (WPPSI-IIICDN)
Measurement Areas:
The Wechsler Preschool and Primary Scale of Intelligence Third Edition (WPPSI-III) is designed
to test intelligence (cognitive ability) in English-speaking children ages 2 years 6 months to 7
years 3 months in the following content areas:
1.
2.
3.
4.
5.
6.
7.
8.

Verbal Reasoning
Concept Formation
Sequential Processing
Auditory Comprehension
Cognitive Flexibility
Social Judgment
Perceptual Organization
Processing Speed

Purpose:
The WPPSI-III is a norm-referenced intelligence assessment tool that can be used to:
- measure general cognitive functioning,
- identify intellectual giftedness, mental retardation, and cognitive strengths and
weaknesses,
- guide treatment program development,
- make placement decisions in clinical and educational settings, and
- provide clinical information for neuropsychological evaluation and research.

Length and Structure:

The WPPSI-III is designed to assess individual children; administration time depends upon the age
category the child falls into. According to the Administration and Scoring Manual, the core
subtests take approximately 30-35 minutes for most children aged 2 years and 6 months to 3
years and 11 months, and approximately 40-50 minutes for most children age 4 years to 7 years 3
months. The younger group requires 4 core subtests, while the older group requires 7 core
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subtests. Several of the subtests have age-based start/finish points and reversal rules that allow
the examiner to reduce the amount of time spent testing.

2 years 6 months 3 years 11 months: Children in this age group must complete 4 core
subtests: Receptive Vocabulary, Information, Block Design, and Object Assembly; Picture Naming
is also available as a supplemental subtest. Based on these measures 4 composite scores can be
calculated: Verbal IQ (VIQ), Performance IQ (PIQ), Full-Scale IQ (FSIQ), and General Language
Composite (GLC).

4 years 0 months 7 years 3 months: Children that fall into this age group must complete 7 core
subtests: Information, Vocabulary, Word Reasoning, Block Design, Matrix Reasoning, Picture
Concepts, and Coding. Based on these measures 5 composite scores can be calculated: Verbal IQ
(VIQ), Performance IQ (PIQ), Full-Scale IQ (FSIQ), General Language Composite (GLC), and
Processing Speed Quotient (PSQ). Additionally, 7 supplemental subtests are available:
Comprehension, Similarities, Picture Completion, Picture Naming, Receptive Vocabulary, Object
Assembly, and Symbol Search.
Supplementary subtests (such as Picture Naming) can either be used to generate additional
composite scores (such as GLC) or can be used to replace a core subtest. Specific rules for subtest
substitution are discussed in the manual.

The number of items in each subtest varies depending upon age group; item score ranges differ for
each subtest (e.g., the Information subtest is scored 0-1, while the Vocabulary subtest is scored 02). Raw scores are compiled and converted into scaled scores, composite scores (VIQ, PIQ, FSIQ,
GLC, PSQ), standard scores, score profiles, percentile ranks, descriptive classifications, and testage equivalents.
Materials:
The publisher classifies the WPPSI-III as a Level C qualification that is targeted to institutions
with personnel possessing masters or doctorates of psychology or education, and/or has licensure
in a relevant area of assessment.
The WPPSI-III is available in several kits: the complete Canadian kit in a box is sold by the
publisher for CDN $1760.00, and includes the Examiner Manual, Technical Manual, Canadian
Manual, 25 Record Forms (for each age group), 25 Response Booklets, Stimulus and Manipulative
Materials. Scoring and interpretation software (WPPSI-III Canadian Scoring Assistant and WPPSIIII Canadian Writer for Windows) are available for CDN $330 and CDN $756 respectively; these
are also available bundled-in with the WPPSI-III kit at a discount.

Accessibility:
The WPPSI-III is available in the English and French languages, with normative guides available
for several different countries (i.e. USA, Canada, and United Kingdom). The Canadian technical and
interpretation manual has a small section on contextual considerations for testing in Canada.
There is also a French version with Canadian norms (Francophone children).

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Administration, Scoring, and Interpretation:

The WPPSI-III manual suggests that the test examiners and scorers have (at minimum) technical
training in test administration. Individuals with formal graduate-level or professional training in
psychological assessment should interpret test results using the 10-step method described in the
manual. The test is moderately easy to administer, easy to score, and moderately difficult to
interpret based on the interpretation guide in the manual, relevant education and experience. The
manual contains an extensive section on interpretation that includes samples of interpretive
reports.
Subscales:
The WPPSI-III consists of 5 subscales: Verbal IQ (VIQ), Performance IQ (PIQ), Full-Scale IQ (FSIQ),
Processing Speed (PSQ), and General Language Composite (GLC). Each subscale consists of the
scores from each of their respective subtests. As discussed previously (see Length and Structure,
above), the number of subscales used in the test depends upon both the selection of subtests and
the age of the child.

Documentation:
The WPPSI-III Administration and Scoring Manual provides specific procedures for administration
and scoring. The [Canadian] Technical and Interpretive Manual has comprehensive chapters on
interpretation, test standardization, norm development, validity and reliability. Examples of
interpretive reports are included in the manual, and show how the WPPSI-III can be used to
improve clinical utility when used with other standardized tests.
Norming Sample:

Note: The following information pertains only to the Canadian edition of the WPPSI-III
The WPPSI-IIICDN was normed and standardized using a Canadian sample of 700 English-speaking
children (50% Female, 50% Male) ages 2 years and 6 months to 7 years and 3 months. The sample
was stratified according to demographic variables such as age, sex, race/ethnicity, parent
education level, and geographic region. According to the authors, 3% of the sample consisted of
children who were identified as having various learning and attentional disorders who were
participating in regular education classes.

The authors maintain that a close correspondence was kept between the samples demographics
and demographic information based on the 2001 Canadian Census. It should be noted that two
northern Canadian regions (the Northwest Territories and Nunavut) were not included in the
sample. Approximately 6% of the standardization sample was First Nations, which closely
matches the 2001 Canadian Census demographic. According to the manual, persons classified as
being First Nations included Inuit, Mtis, and North American Indians. The manual contains a
detailed report of the samples demographic information.
Reliability:

Note: The following information pertains only to the Canadian edition of the WPPSI-III
The WPPSI-III manual discusses three kinds of reliability measures:
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Internal Consistency: A split-half reliability test determined the reliability of scores for two
halves of the test using the standardization samples data. According to the manual, average
reliabilities for the subtests fell between .81 and .94, and composite scales fell between .90 and .96,
both suggesting a reasonable amount of score consistency.
Test-retest Reliability: A separate sample of 104 children was tested with the WISC-IV twice in a
2-7 week interval. The test-retest reliabilities were calculated, and yielded correlations in the .70s
and .80s for both subtest scores and composite scores.
Standard Error of Measurement and Confidence Intervals: The manual also discusses the
degree to which measurement error should contribute to an individuals observed score.
According to the manual, if a child has a FSIQ score of 106, their true score should fall between
101 and 111 points at a 95% confidence interval.
Validity:

Note: The following information pertains only to the Canadian edition of the WPPSI-III
The WPPSI-III Manual also contains a section on validity and validation. According to the authors,
the WPPSI-III taps a broad range of cognitive domains, including: verbal reasoning, concept
formation, sequential processing, auditory comprehension, cognitive flexibility, social judgment,
perceptual organization, and psychomotor processing speed. The technical and interpretive
manual contains a chapter that discusses the rationale for item content in more depth.

Construct and Convergent Validity: The manual discusses an intercorrelation analysis that was
performed on the WPPSI-III to determine how related each of the subtests were to each other. The
authors hypothesized that the subtests would vary in their relations to each other (e.g., subtests
within the Verbal scale would correlate more strongly with each other than if they were compared
with other subtests), and that most of the intercorrelations would support a general intelligence
factor g. Significant correlations were found between all subtests, and subtests generally
correlated in the .50s and .60s with each other. According to the authors, the results suggest that
the WPPSI-III does measure a single factor related to general cognitive intelligence, and that the
scales have strongly-related subtests.

The manual includes a single study that shows the relationships of scores between the WPPSI-III
(Canadian) and Wechsler Individual Achievement Test Second Edition (WIAT-II). The study
consisted of a Canadian sample of 74 children (ages 5 years and zero months to 7 years and 3
months) who were given both tests in a 0 to 6 week period. According to the authors, the PSQ
(WPPSI-III) and Reading (WIAT-II) composite scales showed the lowest correlations between the
tests (.31), while FSIQ (WPPSI-III) and Total Achievement (WIAT-II) showed the strongest
relationship (.78). Other subscale scores were correlated to lesser degrees, which suggests to the
authors that, certain subtests relate differentially to specific domains of achievement.
Publication Information:

This review is based on the 3rd edition of the Wechsler Preschool and Primary Scale of Intelligence
[Canadian] published in 2004 by Harcourt Assessment.
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Materials Used for Tool Review:

WPPSI-III Canadian Manual

WPPSI-III Technical and Interpretive Manual
WPPSI-III Administration and Scoring Manual
Publishers website
Test Reviews

References:
Publishers website: www.harcourtassessment.com
Maddle, R. A. (2004). Review of the Wechsler Preschool and Primary Scale of Intelligence Third
Edition. Mental Measurements Yearbook, 16.
McCurdy, M., & Johnsen, L. A. (2004). Review of the Wechsler Preschool and Primary Scale of
Intelligence Third Edition. Mental Measurements Yearbook, 16.
WPPSI-IIICDN Canadian Manual. (2004). Toronto, ON: Harcourt Assessment.
Wechsler, D. (2002). WPPSI-III Administration and Scoring Manual. San Antonio, TX: The
Psychological Corporation.
__________________________
How to cite this document: This document was created for CUP.
document use the following:

However to cite this

Community-University Partnership for the Study of Children, Youth, and Families (2011). Review
of the Wechsler Preschool and Primary Scale of Intelligence Third Edition [Canadian] (WPPSIIIICDN). Edmonton, Alberta, Canada.

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