Discrepancies in Scores on the WISC IV
By Inderbir Kaur Sandhu, Ph.D
Q: I would greatly appreciate any insight
and advice into my daughter's test scores. These were taken a couple of
years ago and she is now just turned 13. She manages to squeak by at
school and get OK grades, but every day is a huge struggle of
organization and frustration.
She has always seemed 'smart' but reluctant to do the work. As I
understand it this profile doesn't show that she is 'gifted' but the gap
between verbal skills and processing speed are the major source of the
problem. However no one has been able to explain to me the huge
differences in her individual scores (eg in Perceptual Reasoning from a
5 to a 15) and Verbal Comprehension (from 8 to 16).
Are there any clues here for what is really going on, and if so what
should be our strategy in trying to help her reach her potential?
Verbal Comprehension -- 119
(Word Reasoning): 8
Perceptual Reasoning -- 92
Block Design: 6
Matrix Reasoning: 15
Picture Concepts: 5
(Picture Completion): 14
Working Memory -- 91
Digit Span: 8
Letter-Number Sequencing: 9
Processing Speed -- 85
Symbol Search: 7
Full Scale IQ -- 99
Thank you for any advice.
The WISC-IV consists of 10 core subtests and five supplementary subtests
that can be combined in various ways to generate a full scale
intelligence quotient (IQ). For instance, scores from three of the core
subtests (Similarities, Vocabulary and Comprehension) are combined to
calculate a Verbal Comprehension Index (VCI), which is said to be a
measure of a child's ability to learn and reason with words. There are
also two supplementary subtests that fit within the VCI domain. These
are Information and Word Reasoning. If these subtests are administered,
the scores obtained do not generally contribute to the calculation of
the Verbal Comprehension Index score unless there is a clinical reason
It appears that every supplementary subtest was used to assess your
child but none were substituted (two substitution is allowed with
caution). The five supplementary tests in fact add flexibility; however
only two substitutions are allowed in different composite areas in
deriving FSIQ scores (based on a clinical judgement). In your child's
case, none of the substitution was used. You may want to check with the
administrator of the test. For example, if your child has difficulties
with her fine motor skills (a possible reason due to the lower scores in
processing speed), the PSI score may be unfairly impacted because the
core subtest Coding requires a degree of fine motor coordination.
Therefore, Cancellation (supplementary subtest) can be used to
substitute the Coding score. This is because Cancellation score does not
rely as heavily on fine motor skills and may therefore provide a better
measure of processing speed for this a child with fine motor
Her verbal scores are actually similar – the supplementary subtest was
used perhaps to strengthen the evidence. However, the difference is
still within the normal range. The PRI requires visual perception and
organization and reasoning with visually presented, nonverbal material
to solve the kinds of problems that are not normally taught at school.
Block Design requires visual-motor coordination and the ability to apply
all skills in a quick, efficient manner. It tests visuospatial reasoning
and visuo-constructional ability. The highest scores reflect both
accurate and very quick responses. Low scores suggests poor perceptual
abilities, difficulties with visual integration, and likely problems
with maintaining a sustained effort. For picture concept as well, her
score was lowest compared to the other subtests under Perceptual
Reasoning indicating perhaps poor nonverbal concept formation, rigid
thought processes and poor abstract reasoning.
The Matrix Reasoning subtest requires nonverbal reasoning and concept
formation, which your daughter did very well. Matrix Reasoning is about
problem solving/reasoning and Block Design and Picture Completion are
about perception/sensory processing. So once the data is in the brain it
gets processed well, but getting it in may be difficult.
As for the scatter, there is not diagnostic indication but it could like
a pattern in children within the Autism Spectrum. Especially for
children with Asperger's Syndrome, scatter in sub-test scores is
characteristic, and a verbal vs. performance IQ gap is not uncommon.
Having said that, not all autistics have large subscores gaps. It is
true that many do and it could point to a sign that autism can be
considered; but it is not required for nor diagnostic of autism. They
can be useful in determining concerns such as a possibility of NVLD/AS
though, especially when you look specifically at the pattern of subtest
scores that children with disorders often exhibit.
It is best to seek professional advice and perhaps take further
diagnostic tests to eliminate some of the conditions and if any concern
is diagnosed, it is not late at all to start intervention. Do seek
further help. All the best.