Our 3 year old drove the tester bananas for the WPPSI. She tried testing her for 20 min, but my daughter was all over the place and wouldn't answer. AND when she did, she'd give multiple adjective clues to the nouns she was supposed to name. (If it was a banana picture, she'd say, "Isn't it sweet? Isn't it juicy? Isn't it yellow? Isn't it fruit? Does it have seeds?") Then, the psychologist talked with her Group who said it would be okay to try again in a few months (after we had talked with our daughter about just answering the questions with no fooling around). We came back and my daughter remembered the questions one by one. "Number 1", she quoted, "what is a banana?" "Number 2", "What is a car?"
(I can't remember exactly what the objects were, but she could remember them in consecutive order.) That was it. Inconclusive results and no testing for the little girl. She won that round.