Just to clarify that the same test is given and then extended scores can be calculated. Or maybe you were referring to the fact that she was given Information instead of Comprehension? I wonder if the tester usually does that, or if the decision was made in particular to your dd's case. My dd's WPPSI information score was significantly lower than the rest of her verbal scores. When she had WISC a couple of years later, we asked that she got the Information as well.
For extended scores, I just provided our tester with the techical report links and she calculated them for us. I don't think you need to have more than one subtest with a ceiling in order to get extended scores (unlike the GAI for which you do).
BTW, did you get or calculated the GAI?
