DS7 had the WISC IV shortly after his 6th birthday as a part of a neuropsych eval. He scored in the 140s for PRI but only around 114 for VCI. Fast forward 1.5 years later and he is taking above-level tests for reading/math in school, where the ceiling is really high, like a 12th grade level. Given his lowish VCI I suspected he would have trouble with higher level reading comprehension but he is scoring well above the 99th percentile. For vocabulary, the test put him at a 7th grade equivalent, meaning he is scoring like the average 7th grader. I think that his grade equivalent for all the various reading scales was about the same, around 6th-7th grade (like long passage, non-fiction, fiction, etc). But on the WISC he was in the average range for vocabulary and comprehension. I'm trying to figure out why the tests would yield different results. Obviously a reading achievement test is not an IQ test, but they ask similar things (like defining vocab words). Could it be just the format of the WISC (where kids have to give an oral answer/explanation) vs. the multiple choice version of the reading test? Anyone else experience this? DS is actually scoring higher on the reading tests (including vocabulary) than DD did at his age, and she was in the 130s for VCI on the WISC (and her reading fluency was excellent so poor decoding ability wouldn't explain it). I would love it if the WISC was wrong and he does not really have the huge gap the way I thought he did--but who knows. I'm also debating whether to allow the school to give him the CogAT. Maybe he'd actually do better on it than the WISC.
