Interpretation of WISC IV and WIAT Scores
By Inderbir Kaur Sandhu, Ph.D
Q: My 6 year old has been underachieving and shows a general disinterest in school. But he loves to learn - he reads constantly and loves social studies, geography etc. He can memorize facts and understands high concepts about history or any subject that interests him but struggles with simple math. We are trying to make school decisions for next year so we had him tested. His scores are confusing to me.
On the WISC IV, he had a 134 Verbal score (99%) but his other indexes were in the average range.
On the WIAT, he was 99 % for all the reading sections including (140) for total reading and 98%in total Math.
There was also indications of possible ADHD. We tried 2 medications and neither worked. My questions are:
1. What does it indicate if the verbal score is so high but the other indexes are average? Does this mean a learning disability or merely his personal strengths and weaknesses? I know he asked the psychologist several times when he would be finished so he could go back to school.
2. Why are the achievement scores so high and the aptitude scores so scattered?
3. Does this profile consistent with ADHD?
4. What are your thoughts on Vision Therapy? We tried it but he would not put forth effort.
Thanks so much!
A: From your description, it appears that your son is a bright child. At 6 years of age, it is hard to tell if a child is underachieving unless he is developing slower than his peers, which does not seem to be the case here. It is going to be hard to interpret without the breakdown of other subsets. His WISC-IV verbal score is in the Superior range and the others are average (as you mentioned). But is the difference significant? If there is a significant difference between some of the scores, he would have a GAI instead of an FSIQ. I will attempt to respond to your queries as best as I am able to.
1. The Verbal Comprehension Index (VCI) assesses the child's use and understanding of language using subtests that assess abstract reasoning, vocabulary development, and common sense reasoning. It emphasises crystallised intelligence and knowledge application. A child with a high score in Verbal Comprehension can participate in conversation, understand directions, follow classroom discussion, and explain his ideas much better than other students his age. Other scores are average which indicates a relative weakness in comparison to his verbal scores. However, a very large difference between VCI and PRI may indicate a non-verbal learning disability.
In general, intelligence tests provide information about a student's intellectual strengths and weaknesses, as well as insight into overall cognitive potential. It gives general information about a student's abilities compared to other children of the same age in several areas. It is a predictor of how well and in what ways a child will learn new information. Scores are considered valid only if testing conditions were adequate and there is minimal variability in scores among the various scales on the assessment. When there is a significant scatter between the different areas, the overall score will not be representative of a child's overall potential. A closer look at the breakdown of the scores would indicate the relative weaknesses/strength. The final score is in comparison with the standardised sample. Bear in mind that close to 70% of the population will perform in the Average range. A higher or lower score from the average would indicate less typical scores.
2. The WIAT is an individual academic achievement test, which measure specific academic skills compared to other children at the same grade or age level. Such tests focus on Broad Reading, Writing, Math, and Oral Language skills and also different aspects of the broad areas. The difference from classroom assessments (that measure skills that have been taught) is that these tests measure basic academic skills.
In general, scores on an intelligence test and achievement test would be quite similar. If there is a large discrepancy between the scores, it may signify a learning disability. Having said that, there are many reasons that cause this difference. Your psychologist would be able to tell based on the breakdown of the scores.
3. The indications in any intelligence test are not diagnostic of ADHD, but may be an indicator. Again your psychologist tester could check the table to tell exactly what percentage of the population would have this scatter or if it is normal. While the WISC-IV is not a diagnostic test for ADHD, there are patterns that you often see in the scores for these children. Prior studies have demonstrated an association between ADHD symptoms and weaknesses in both working memory and processing speed. Nevertheless, one cannot diagnose ADHD from these tests alone.
Since all his other scores is in the average range, it could also be that rather than a learning disability, it could just be an area of high strength in verbal ability and relative weakness in other areas.
4. Vision therapy is an individualised supervised treatment programme designed to correct visual-motor and/or perceptual-cognitive deficiencies, which have various causes, such as inadequate sensorimotor development; trauma to the nervous system stress; and in some cases, contributing hereditary factors (i.e., crossed-eyes, wandering eyes). Many symptoms of visual disorders mimic symptoms of dyslexia, ADD and ADHD. So first you would need to determine that your son really has ADHD and functional vision problems. Since medications did not work, please do check this out to determine this therapy.
Hope this sheds some light to your concerns. Your son is very young; perhaps he should not be subjected to too many tests at this stage unless there is a real need. His disinterest may be due to frustration or boredom in school. See a good psychologist and do try to get him to talk about his difficulties in school (if any). Good luck!
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