Makes sense. The GAI is skewed high for my child because processing brought the FSIQ down to 147 (minimum - hit four subtest ceilings). That would make the scores far more common, right?
More common but still unusual
FWIW, my understanding is that when there is a greater than 1.5 SD difference between subtest scores, the FSIQ is not valid, so I wouldn't use it to describe my child's abilities. I have a 2e kid with a large spread between subtest scores - so we use the GAI when we are trying to frame his intellectual strengths. That's not saying we ignore the other subtest scores, but his lower FSIQ score is more of an average that lies somewhere between the high GAI and the lower processing speed/wm… hence it's more like a meaningless number - it doesn't tell you much of anything at all about ds, other than what would happen perhaps if you averaged a numerical representation of his strengths and not-quite-as-strong abilities.
I suppose that some would then counter with - well, isn't that what FSIQ is for everybody, but from my understanding, most people do not have those huge discrepancies in between FSIQ subtest scores, so averaging subtests for the typical person is valid.
And I realize I used "averaging" in a broad sense here, because FSIQ isn't a straight average, I think it's weighted a bit between subtests.
polarbear
