If you were to ask your parents and teachers the ultimate question, how do you think it would turn out for your school? With this in mind, read The Ultimate Question 2.0 by Fred Reichheld. It will give you excellent insights into how your school can be measured with one question. Reichheld has so much to say about profits v. service.
Oh . . . what's the question? Well, I guess I can pass that on . . .
"On a zero-to-ten scale, how likely is it that you would recommend us (or this product/service/brand) to a friend or colleague?"