IQ Tests Which Score is BEST?
Should we use the overall one-number-to-say-it-all full scale score on IQ tests?
ARE ALL YOUR CHILD’S SUBTEST SCORES CLOSE? If yes, then a full scale score is fine. If not, it may not be appropriate.
We somehow need to help evaluators understand the far-reaching effects of using just the one full scale score to give a summary quick picture of a child’s IQ. If the four “area scores” that make up the full scale ( verbal, nonverbal, working memory and processing speed) are all about the same, not TOO far apart, then using a combined score, the full scale IQ, makes sense. However, with students with learning disabilities, not only do we often see deficits in the verbal area but we often see lower scores in working memory and/or processing speed. This is not due to lower intelligence but problems SHOWING their intelligence using those measures (like asking a visually impaired person to prove his knowledge of the rules of baseball by describing what’s happening while watching a game). The main take away from the discussions about IQ testing is do not use full scale scores when there is significant inter or intra test scatter within the IQ test. Using the full scale score as an indication of a person’s true overall intelligence is like describing a shirt that’s part light blue, part dark blue, part light green, and part dark green, as “overall turquoise.” Yes, it’s that absurd.