I was going to suggest private testing as well if the school will accept it. We saw a huge difference btwn scores on the CogAT (another group test) and the WISC for our anxious, 2e dd. She also had a horrible year and teacher fit the year she was tested on the CogAT.

Another thought is regarding group tests. There is a note on Hoagies about a study that shows a negative correlation with IQ scores for the OLSAT in HG kids; the more HG the child, the lower the OLSAT scores. The opposite held true in the study for average kids (OLSAT scores correlated pretty well with IQ).

Point being, if there is any possibility of ongoing anxiety, 2e issues, or a divergent thinker, an individual test would probably be a better way to go.