Disparity between the Verbal Comprehension Index with Others (WISC-IV)
By Inderbir Kaur Sandhu, Ph.D
Q: 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. Good luck!
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