I do like to call on random kids, and my policy is that I don't like to just give up if they have the wrong answer. I try to work that kid through to the correct answer. With that said, apparently the new evaluation system we're using deems you "ineffective" in one of the categories if you only call on kids raising their hands. I think that's a bit harsh, although I do see the point as I'd only be hearing from a small handful of whippersnappers if I didn't call on people randomly. Do you call on people randomly, or just take volunteers?