I entirely agree with in-class exploration, but as a teacher who did say, "yes" as often as possible to a 6th grade science class, I found the principal and other teachers were not for this approach at all. I only lasted a year at that school and when I had my performance review, the principal told me the best way to teach was just read from the chapter Monday and Tuesday with students taking notes, quiz on Wed, Thurs some controlled experiments and Friday a test. Uggghh.