From what I understand, the FSIQ gives the best overall picture of what you're capable of, as working memory and processing speed directly affect how well you can learn.
I'll respectfully disagree with this as a parent of a child with a significantly lower processing speed than other areas, and a higher GAI than FSIQ. What that difference tells you isn't about the "ability to learn" it's about the "ability to output" (processing speed), which can be as insignificant as the ability to make marks quickly on paper. Working memory relates to the ability to juggle multiple things in your head at one time - having a lower WM isn't going to mean a person isn't less capable of learning than a person with a higher WM, it just means they might learn in a different manner.
I also, personally, feel that there are a lot of things that aren't measured on IQ tests that will go into determining what any one person is capable of in life - motivation, circumstances, passion, interests.
Re the WISC (and other ability tests), I think that there is no real answer to the question "which number is 'more accurate' "... I think that if you have test results that you feel were obtained when your child was attentive and not distracted or feeling ill or whatever (ie, test results you trust), what you have are a set of numbers that *all* accurately reflect different types of abilities.
polarbear
