I'd go by what you know of your child, but it seems to me there are two possibilities, that either the achievement test is an overestimate or the IQ numbers are an underestimate.
FWIW, we have had this situation occur in the case of a late bloomer with processing issues (of a language variety, among other things) that held down the wisc scores even for PR. In later years, another test showed higher IQ scores more in line with achievement, though we have yet to repeat the wisc so it's hard to say for sure what was going on. This kiddo was obviously gifted in math from an early age in spite of his issues and remains advanced.
I asked the school psych how someone could score so much higher by percentile on achievement than IQ testing, by a couple standard deviations, and she didn't seem to have an answer. When I asked the private psych on another occasion, she muttered something about my children being complicated, but mostly referred to the "language processing issue."
Last edited by snowgirl; 10/20/15 05:02 PM.
