Interpretation of WISC-IV Scores

Q: I would appreciate some input on how to interpret my daughter's results and possible meaning of her scores on the WISC-IV. She has a 27 point difference between PRI (high) and the VCI (lower), which makes a FSIQ uninterpretable. My reason for asking is that, given her high intelligence, could she be compensating for some type of learning disability- auditory, language, reading etc?

I want to help her reach her full potential and am wondering whether or not we should get any type of further testing. The school did not do the WISC, we paid for it ourselves and I think that, because she is reading and writing at grade level, the school will not perform any tests themselves and we are the ones who need to pursue this. I have asked the psychologist who administered the test for any clarification of the meaning, her response is the she just has a relative weakness in her verbal comprehension.

Here are her scores:

Subtest Scores on the Wechsler Intelligence Scale for Children, 4th Edition (WISC-IV) Standard Score or Scaled Score:

WISC-IV Full Scale IQ - 126

Verbal Comprehension Index - 108

A: In general, her scores are rather high and for a score in the superior range, as a rule of thumb, the FSIQ starts from 123, though some sites indicate a higher score at 130. Her scores are being referenced to other people within her own age group (you did not indicate her age). The average IQ is 100; so deviations from the average are assigned a number which corresponds to a percentile rank.

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 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 daughter scores highly.

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). However, this is only possible if the difference between VCI and PRI is less than 23 points – which is not possible in your case with a high difference of 27.

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.

As for the high PRI scores, they indicate high visual perception and organization, and reasoning with visually presented, nonverbal material to solve the types of problems which are usually not taught in schools. Block design also requires visual-motor coordination and the ability to apply all skills in a quick, efficient manner. High scores reflect both accurate and very quick responses.

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 she has a language deficiency and perhaps you may want to consider a verbal test. Seek help from a professional. Good luck!

Essentials of WISC-IV Assessment
Dawn P. Flanagan Ph.D, Alan S. Kaufman Ph.D

The WISC-IV is the top intelligence assessment instrument for children in the US, providing essential information into a child's cognitive functioning. This book applies a new, expanded theory-based approach to interpreting the latest edition of the WISC® and provides beginning and seasoned clinicians with comprehensive step-by-step guidelines to administering, scoring, and interpreting this latest revision of the Wechsler Intelligence Scale for Children.

This book provides students and practitioners with an unparalleled resource for learning and application, including expert assessment of the test's relative strengths and weaknesses, valuable advice on its clinical applications, and illuminating case reports.