This can go somewhat badly. I had a professor who did something like this. He would assign reading and spent a lot of time answering questions, sometimes around

This can go somewhat badly. I had a professor who did something like this. He would assign reading and spent a lot of time answering questions, sometimes around a half hour or so. The bad part is that he would not require homework to be turned in until the evening, so the questions have ended up being over homework. This means that if you have done the homework correctly, there is a fair amount of wasted time in class. So it seems to benefit more the people who didn't actually finish the homework before class.