Some comments on grading

1. My grading (at least when I do it myself—and I ask TAs to do the same) is intended to be rather bimodal. I try to give more than half the possible points to any answer that is basically correct, and fewer than half the possible points otherwise. I have observed that this translates to less partial credit than many students are used to. In the “extreme” version of this grading convention, your score is simply the number of problems that you correctly solve. I like this idea, and have tried to implement it, but I find it not quite feasible: too many student end up with near-zero scores. Still, I do try to approximate this to some extent. The upshot is that if you’re a student who survives on partial credit, you may end up with a worse grade in my class than others.

   I grade this way because I like things to be right and I think you should know when you do and when you don’t know something. If you can’t solve a problem, just say so, and explain what you’ve tried. It doesn’t bother me when a student can’t solve problems I ask after all, I can’t solve most problems I try to solve, either. It bothers me more when they try to “fake” an answer, try to “adapt” a solution they don’t understand, or don’t know that they’re saying things that don’t make sense.

2. On true/false questions that don’t ask for justifications, I sometimes penalize for wrong answers, but never to the extent that you are wrong (in terms of maximizing expectation) to guess. The purpose of taking off for wrong answers in true/false questions is just to normalize scores so that “knowing nothing” doesn’t give you an expected 50% score. (After all, 50% is only a little worse than the median grade one too often sees.)

3. I will occasionally and intentionally let your solution to one problem or problem part influence the grade you get on another problem or problem part. I find it infeasible to do much of this, but I see an exam as a single piece of work, and certainly don’t see anything “wrong” with linking problems in this way.

4. Exams might ask for a short essay. I started doing this a few years ago, after reading a piece by a physicist who explained that, when he was a graduate student, there were graduate students who were great at solving the highly technical kinds of problems that were on exams, but who couldn’t actually explain, and didn’t really understand, the simplest of physical phenomenon. Such students are not good physicists, the author maintained, and I would certainly agree. I’m sure we have the same kind of phenomenon among CS/CSE undergraduates. A genuine and useful understanding of a subject like ECS 120 includes the ability to synthesize and explain what you have learned, and to do so in an organized, articulate, and grammatical fashion.

5. Grades are inherently “noisy” and, ultimately, a bit silly. Please don’t stress out over them half as much as I stress out over assigning them each quarter; it is, I am sure, completely non-productive.

Phil Rogaway