Thursday, December 22, 2011

My theory on grades

I wish students typically got a B in my course.
C's would be reserved to the students who stand out because they're at the lower tail of the distribution (something of the order of 5 percent of the students), and
A's would be reserved to the students who stand out because they're at the upper tail of the distribution (also something of the order of 5 percent).
This way students would expect to get a B, the bulk of the students would get the grade which they expected to get, and the occasional A would be a pleasant surprise.

As it happens, this semester my class was so good and hard-working that I gave a very large number of A's (40 percent!!), which meant that the cutoff point fell in the dense part of the distribution of grades, which meant that it was rather arbitrary: between the 20 "A students" with lowest average grade, and the 20 "B students" with highest average grade, I bet that the difference in performance is statistically completely insignificant. That's a lot of students who will curse their bad luck or question my judgment!

But even for next semester, I don't dare try my theory. B versus A grades don't really matter very much anyway for Brown CS students. The expectation is that they work hard, learn well, and get a good education. Whether that means giving A's to the majority (because we're so pleased with them), or giving B's to the majority (because they're doing as expected, and it's difficult for a student to stand out in an environment in which most are putting so much effort into their coursework), really does not matter much.


  1. As vs Bs do matter to CS students. As lead the way to grad school: Bs shut that door.

  2. Anonymous, that's not true for Brown students...

  3. You mean they don't have problems getting into the graduate program of the University of Banana Republic?

  4. They're good students to start with, they work hard and get a good education to build on that good start, the ones who are so inclined can give research a try, and then, if they wish to, they go to a good graduate school.

    Simple! At least in theory.

  5. What if they want to go to other graduate schools? Average GPA of B will ruin their academic life. You should see this issue from student's standpoint as well. If everyone is good, all of them should get a grade that is reserved for good students. And the difference between A and B should be significant (and not arbitrarily close).

  6. I think grad school needs to realize that B is not a bad grade. However, I do agree that whomever-deserves-an-A-gets-an-A is the best policy. If there are so many people (say %40) doing well, you may need to challenge them more without hurting students outside that group.

  7. As a TA, I taught at a large university where the curve was designed so that the overwhelming majority of undergrads got C's. "The overwhelming majority gets" anything is very depressing: students coasting, other off to a bad start and working really hard and improving their scores, students in a tailspin... same end result, same grade.