I have a few comments about people leaving the class 5 minutes early. I have a had complaints from other students who are disturbed by people leaving class early. You have all paid to listen to me give a 50 minute lecture, so why would you want to leave before the lecture is over. I intend to put questions on the exams which are based on material that I cover in the last 5 minutes of class. When people leave early, I think it says something about their commitment to do well in the class. It would not surprise me if people who leave early also skip class or discussion sections occasionally, and it would not surprise me at all if the same people get a low grade for the class.