Score Difference Between CAT4 And WISC-IV
By Inderbir Kaur Sandhu, Ph.D
When my son was 10 years old he was tested by the school psychologist
using the WISC-IV. His results were as follows:
Verbal Comprehension Index - 132
Perceptual Reasoning Index - 137
Working Memory Index - 102
Processing Speed Index - 109
Full Scale IQ - 129
The psychologist said that these scores put my son in the 97th
percentile which was very surprising for my husband and me. The reason
we had him tested in the first place was because he was struggling and
doing so poorly in school.
He is now 14 years old and just started grade 9. He recently took the
Cognitive Abilities Test Fourth Edition (CAT4). It was my understanding
that the CAT4 assesses some of the same attributes as the WISC-IV,
however my son scored average on the CAT4 (above average for Verbal,
normal range for Quantitative, Non-verbal and Spatial).
My questions are as follows:
Do the WISC-IV and CAT4 assess similar attributes?
Do you expect a child with a high IQ (according to the WISC-IV) to do
well on the CAT4?
What explanation can you provide to explain the discrepancy between
CAT4 is the Cognitive Abilities Test used to test reasoning abilities
for pupils aged 7 to 17+ years. CAT4 assesses a pupil's ability to
reason with and manipulate different types of material through a series
of Verbal, Non-Verbal, Quantitative and Spatial Ability tasks. Together,
these four tests provide teachers with a comprehensive profile of a
pupil's reasoning abilities, and as such the core abilities related to
learning. This is a UK based test.
In general, the CAT4 is a group-administered test, while the WISC-IV
batteries is individually administered. Just this factor alone makes the
two tests quite different as it can affect the performance of some
children. For instance, those with attention problems may lose focus
during a group test (CAT4) but remain 'on-task' with one-to-one testing
(WISC-IV). The WISC-IV involve the examiner reading the material to the
pupil, while the CAT verbal tests require the pupil to read the
materials, so this may be a factor. Additionally, the WISC-IV
incorporates a wider range of cognitive tasks; so overall performance
may be affected by specific abilities not assessed in CAT. For both CAT
and other IQ tests, scores can sometimes vary because of extrinsic
factors such as tiredness, distraction, lack of motivation, incorrect
Where there are score differences between two tests one needs to know
something about the individual who is the focus of the assessment.
One-to-one work with, or observation of a student over the course of a
school day can sometimes be far more informative than a whole battery of
test scores. Perhaps the important message is to use all the available
evidence, from every source, when making any educational decisions. You
may want to speak to the administrator to find out in detail reason for
the score difference.
On the WISC-IV, he appeared to score much lower in
the non-verbal subtests, which may require some intervention and
training. Perhaps, not much was done here which resulted in lower scores
in CAT4. Please check with the CAT4 administrator for better explanation
by looking at the breakdown of scores.
All the best.