
Confusion over WISC-IV scores
By Inderbir Kaur Sandhu, Ph.D
Q:
My son who turned 7 (5 days before he took the WISC-IV test) had the
below results come back. Our district and the state of Ohio say that a
score of 127 and above is considered gifted determined that he isn't
gifted. His score was a 126. Because of this I have requested the
overview and this is what he received.
Block Design raw score - 39 scaled score - 16 Similarities raw score -
10 scaled score - 10 Digit Span raw score -18 scaled score - 16 Picture
Concepts raw score - 17 scaled score - 14 Coding raw score - 65 scaled
score - 19 Vocab raw score 20 - scaled score - 10 Letter-Num Seq raw
score 15 - scaled score 13 Matrix reasoning raw score 17 - scaled score
13 Comprehension raw score - 15 -scaled score 11 Symbol search raw score
29 - scaled score 13
Sum of Scaled scores:
Verbal Comprehension sum of scaled = 31 VCI 100 percentile rank of 50
Perceptual reasoning sum of scaled = 43 PRI 127 and percentile 96
Working Memory sum of scaled = 29 WMI 126 and percentile 96
Possessing Speed sum of scaled = 32 PSI - 133 and percentile 99
Full scale sum of scaled = 135 FSIQ = 126
I have several questions:
1) Can the FSIQ be used as a good indicator even though the Verbal is 26
pts - 33 pts lower then the other three (Perceptual, Working Memory, and
Processing speed) It seems like this may be saying something. Is it
saying he doesn't do well at verbal versus visual? Should the test be
looked at differently because of this?
2) I have read that some people believe the cut off should be reduced to
120 vs 130 that some use because this test results on research show
gifted kids scoring lower on this then the old version and the Stanford-Binet
Intelligence Scale.
3) I guess I am wondering if I should have him retested because of this
large variance?
4) He turned 7 5 days prior to the test being given. How would the test
score results would have been if he had been 6 or taken the test 5 days
earlier?
5) Did he reach the ceiling on any of the categories based on these
scores?
Thanks for your help. Just frustrated because we feel he is bored but
results didn't quite show he should be in the "gifted" category.
A:
It appears that some WISC subtests are good measures of general
intelligence; others are poor measures of general intelligence. WISC
full scale IQ is not necessarily a more valid measure of intelligence,
especially the kind of intelligence that is required to succeed in
school. So at FSIQ 126, he should be in the above average category and I
believe deserves differentiated curriculum. However, different schools
have different policies with regards to this. The cut-off can be between
123-130; depends on the program and criteria used to select students by
the respective organizations.
My concern is the VCI (read the
technical terms in the WISC IV). Verbal Comprehension and Perceptual Reasoning
tasks are heavily loaded on abstract reasoning ability and are better
indicators of giftedness as compared to Working Memory and Processing
Speed. In this case, there are extremes in both the scores, VCI being
very low and PRI being very high. The subsets for VCI represent key
clinical indicators of the cognitive strengths and weakness considered
important to the assessment of learning disabilities, executive
functions, attentional disorders, traumatic brain injuries, mental
retardation, lead poisoning, giftedness, and various other medical and
neurological concerns. On the other hand, the PRI emphasizes on fluid
reasoning abilities as measured by the Matrix Reasoning subtest and
Picture Concepts subtest – which your son scored highly.
The VCI describes verbal conceptualization, stored knowledge access and
oral expression. The child is required to answer orally presented
questions that assess common-sense reasoning, reasoning out or
retrieving word associations and the ability to describe the nature or
meaning of words. Verbal expression is required here. Low scores here
may indicate a possible difficulty with language, weak fluid reasoning
skills in verbal domain, or even possible hearing concerns.
The Verbal Comprehension and Perceptual Reasoning Composites are both
very good indicators of giftedness; they assess verbal abstract
reasoning and provide useful tests of visual reasoning with less timing
emphasis. In your case, due to the significant difference between the
VCI and PRI, the WISC-IV Full Scale IQ scores for the gifted may be
difficult to interpret. In this case, you could consider the GAI
(General Ability Index).
As a rule, the GAI would be considered in a number of clinical
situations (though not limited to) as the following:
-
a significant and unusual discrepancy exists between VCI
and WMI,
-
a significant and unusual discrepancy exists between PRI
and PSI,
-
a significant and unusual discrepancy exists between WMI
and PSI, or
-
a significant and unusual subtest discrepancy between
subtests within WMI and/or PSI.
In your son’s case there is a significant and unusual discrepancy
between VCI and WMI. This means, his GAI should be looked at. To retest
using a standardized test, it may require a gap of 2 years. If you used
the WISC-IV, perhaps you may want to try the SB-V. He reached the
ceiling for the PS at the 99th percentile which indicates strong
abilities to focus attention and quickly scan, discriminate between, and
sequentially order visual information. It requires persistence and
planning ability, but is sensitive to motivation, difficulty working
under a time pressure, and motor coordination too.
It would be best for you to sought further help as a more detailed
interpretation or other tests may be required to understand the
difference in scores. It is possible that he has a language deficiency
and perhaps you may want to consider a verbal test. A professional in
this area may be best to seek help. Good luck!
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