Class Participation: How and Why?

I have been rethinking my approach to class participation, and invite your suggestions about how to grade that aspect of student performance, if at all.

Last semester, in Property I, I based 10% of the students' grades on class participation. They won points for class participation in a variety of ways, including serving on review teams, filling out short ungraded quizzes, and signing an "on deck" sheet for Socratic questioning. Despite those many inputs, I still ended up with a very tight cluster of scores, making it difficult to generate a curve that satisfied Chapman's somewhat challenging specs. (My other class, a Law & Economics seminar, raised similar problems.)

I've tried in the past scoring class participation on a more subjective basis, marking the seating chart immediately after class to indicate which students has won class participation points for contributing to discussion of the assigned materials. Although no student ever challenged that system for fairness, it admits the claim all too easily; I prefer more objective measures of performance. Also, I found that scoring students during or after each class, based on some rough measure of "added to class discussion," invited pestering along the lines of, "Did you count my performance, today, Professor Bell? I didn't see you mark the sheet, and you confess to being absent-minded." Fie on that.

I could give up entirely on grading class participation. I don't recall my profs at Chicago keeping track of student participation, after all, unless perhaps for casual dissection in the faculty lounge, and they taught very well. Perhaps I should just stick to exams, and run the risk of teaching to students unprepared for class and unrepentant about their ignorance.

I promised my students that, before I decided how to assess class participation in Property II, I would seek informed advice. If you have some to share, I would welcome hearing it, in the comments below or privately. Thank you.