When DD was tested at 7, the tester suggested that the test could be spaced out over several sessions, even on different days, because it's a lot for a young child. They had excellent rapport, DD was super cooperative, and they went for several hours (if I recall correctly). This was the WISC IV.
I did make a point of telling DD beforehand that the way the test worked is that the questions got harder and harder and that the whole idea was that eventually she wouldn't know the answer. That they got so hard that hardly any grownups would even know them. I was concerned about perfectionism and anxiety.
We received our results within a short time (a week maybe?).
