Disparity between the Verbal Comprehension Index with Others (WISC-IV)
By Inderbir Kaur Sandhu, Ph.D
The results of my 9 year-old son's WISC-IV test were as follows:
I have been told the statistically significant spread between the VCI & the PRI
renders the FSIQ inadequate as an indication of his abilities. Are there
reasons other than ADHD which would account for this disparity between
the VCI and the other results? Thanks much.
A: Briefly, the VCI is measures verbal
concept formation, which assesses children's ability to listen to a
question, draw upon learned information from both formal and informal
education, reason through an answer, and express their thoughts aloud.
It can tap preferences for verbal information, a difficulty with novel
and unexpected situations, or a desire for more time to process
information rather than deciding then and there. It is believed to be a
good predictor of readiness for school and achievement orientation, but
can be influenced by background, education, and cultural opportunities.
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, both
scores are on the higher side compared to the other two indexes. 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.
Your son has a rather high VCI, which accounts for about 62% of variance
in general intelligence. Based on the VCI, it does not clearly indicate
ADHD (average scores for children with ADHD is around 99-100 for VCI).
However, there is a clear disparity with the other score.
Did you get a General Ability Index (GAI) measure? Perhaps, this may be
more accurate that the FSIQ. Research studies have indicated that
students with some disabilities (students with learning disabilities,
students with attention deficit hyperactivity disorders, etc.) were
likely to score lower on the Arithmetic and Coding subtests. To reduce
the effects of these subtests on the FSIQ, the GAI was calculated by
adding up the remaining eight subtests. The WISC-IV FSIQ is more
affected by cognitive processes. Therefore, the GAI was developed to
provide a summary score that is less sensitive to the effects of working
memory and processing speed.
To understand the disparity better, a detailed score of all the
categories in the subset would be required. I suspect a learning problem
with such disparity but it would be best for you to seek a professional
for help as I believe that there is a problem here that needs attention.