Range of Scores on the WPPSI-III
By Inderbir Kaur Sandhu, Ph.D
Q: I live in Atlanta and as part of the
private school admissions program here, children are required to take an
IQ test.. It is the Weschsler Preschool and Primary Scale of
Intelligence III. I just received my 5 year old son's results and his
scores fell in the average range for Verbal and Performance but his full
scale IQ was in the high average range. How is that possible? Isn't the
full scale based on the Performance and Verbal? Why would the full scale
be better than both the verbal and performance? Could this indicate a
problem. When my daughter took it 2 years ago, she cored superior for
verbal and full scale and high average for performance.
Thanks so much for your input!
I am not very familiar with the WPPSI but I will try to shed some light
test is a very respected test of intelligence from the
family of Wechsler’s series of tests. It is important to remember that
such tests yield results in a range; it is not possible to say with
precision what any particular child's IQ is.
The WPPSI-III does not require the child to read or write, hence the
suitability with younger children. Four composite scores that are
included are the Verbal IQ (VIQ), Performance IQ (PIQ), Processing Speed
Quotient (PSQ), and the Full Scale IQ (FSIQ). Briefly, Verbal IQ is
based on Information, Vocabulary, and Word Reasoning. Performance
(fluid) IQ is based on Block Design, Matrix Reasoning, and Picture
Concepts. Processing Speed Quotient (or visual-motor, clerical speed and
accuracy) includes Coding & Symbol Search. Finally, the FSIQ is based on
seven tests: 3 Verbal, 3 Performance (fluid), and 1 Processing Speed
test. Each of these IQs are composite scores. Both the Verbal and
Performance IQ scores are composites of five different subtests, each of
which measures a different area of ability. The Full Scale IQ is a
composite of the Verbal and Performance scores, which makes it a
composite of 14 different subtests. The individual index scores (VIQ and
PIQ) and the FSIQ are calculated from a sum of the scaled scores
(excluding the optional subtests).
Hence it is best to check the detailed scores to see how the scores are
derived. You may want to see a professional with the detailed scores.
There may be additional criteria and calculation included that helped
raise up the FSIQ. Still, you should see someone to rule out any
You may also want to use the scores with caution as there are
limitations of using assessments. Some studies show that intelligence
tests such as the WPPSI-III, especially for pre-K level, are unreliable
and their results vary widely with various factors such as retesting,
practice (familiarization), test administrator, time and place. There
are claims that some commercially available materials improve results
simply by eliminating negative factors through familiarization which in
turn puts children at a comfortable frame of mind.