Jacob Levy and Matthew Yglesias have been having a discussion about taking attendance in class.

My general policy is not to take attendance, for a couple of reasons; one, it wastes time (particularly in a large class), and two (if you do the “pass around a sign-up sheet” method), it encourages petty fraud. However, in my intro class I do offer “virtually nobody showed up” extra credit a couple of times per semester (usually worth some small number of points toward the quiz average, generally only when attendance dips below 50%), and occasional announced quizzes. I have heard rumors of universities that have “swipe your ID” attendance systems for large lectures, but I’ve never witnessed one myself. My general philosophy is that if a student really doesn’t want to be sitting in my class, I don’t particularly care if he/she is there either. Call it mutual indifference. There is a strong positive correlation between attendance and grades even without a formal participation score, so I really don’t feel the need to compel attendance through grading policy.

I don’t take attendance at all in upper-level courses. I do keep mental track of the attendance record of students to help decide how lenient I want to be when they come begging for grade bumps, though. (Ole Miss doesn’t give plus or minus grades, except in the law school, so a few points can make a big difference in class grades.)