I talked to our school guidance counselor yesterday, and she said that typically it's only the non-verbal section of the CogAT that correlates with the WISC, because WISC doesn't really have any quantitative section. My daughter's worst section was non-verbal, and it did indeed almost match her WISC GAI.
This certainly wasn't the case for my dd, but the verbal section of the CogAT is actually the one that correlates with the WISC more so than the nonverbal part.
This study has the correlation btwn the verbal section of the CogAT and the verbal index of the WISC-III at .87 and the nonverbal part of the CogAT only having a .64 correlation with the performance index of the WISC-III. I only skimmed the article, but I do believe that the subjects of the study were above average but generally not gifted. It would be interesting to see the correlation when using kids with gifted identifications only.
