A grumpy view of grading…

Well, I expected to start this blog off on a different foot, but being the Grumpy Geophysicist, it took getting good and grumpy to get me going. And so our timely topic of the day is:


Of course these are the bane and goal of nearly all undergraduates (not to say K-12 students as well), but many don’t realize that it is the bane of those of us who teach (and yes, GG teaches at a big public university).  But my carp today isn’t just grading, it is the expectations of the numbers.

You know, “I got a 60 on my exam, I’m going to fail.”

So many students are fixated on the idea that numeric test grades should be 90 for an A, 80 for a B, etc. This is ridiculous!

Think about it.  On that grading scale, an F is below 60.  This means that more than half of the questions on an exam are ones everybody should be able to answer.  What’s the point? I get the feeling that a lot of students are now conditioned to think of the numeric exam score as somehow validating their learning.  Sorry, no.  Exam scores are to determine who knows the material well and who doesn’t.

So a sensible exam should have no gimme questions.  Ideally the average would be 50, not 75, and an F would be near 20, not 60. (If you know half the material on the exam, should you really be failing?). But what happens when exams are scored this way? Tears, angst, and hurried visits to Rate My Professor to be sure to let the world know how unfair this all is!

C’mon, there isn’t even a letter grade yet, and GG warns students that the grades will be curved. Let’s all take a deep breath…. inhale…exhale.  Good.

Now in reality we have to be careful; in my case, in a big intro class, the exam is multiple choice. With 5 answers by random luck we expect 20% success. So we don’t want to quite bend things so low that the noise of luck is affecting passing or failing, so a mean grade somewhere near 60% might be a good target.

So GG gets a bit weary of the angst of college students who get a 66 when the class average is 63 and want to know HOW COULD THIS BE! IN AN INTRO CLASS! Sorry, my goal was not to salve your conscience, it was to separate those who got it from those who didn’t, and you know what?  That exam worked OK for what I needed it to do.  Otherwise with my 20 questions (say), dumb luck either way on two questions could make a B student get an A or a C. By increasing the spread, it now takes 3 or even 4 lucky answers (good or bad) to shift a whole letter grade. By spreading the scores I have made my exam more reliable.

But, well, it feels so bad!

Hey, it feels bad on this side of the fence too.  I spend a lot of time developing materials for class, working on revising lectures and improving things so that concepts are more clearly presented, and it hurts from this side too when I see scores of 40 and 50. When you realize 20 is luck, it means only 1/5th or 1/3rd of what I taught made any impression at all.

So for any students reading this, quit obsessing on the number on your exam.  I know some of you have to obsess on grades because of scholarships or parents’ threats. Really, what will matter the most in the long run is how much you learned, and grades are at best a rough guide.  You can learn a lot and get a lousy grade for a lot of reasons; that should be a success.

And if it makes you feel any better, the Grumpy Geophysicist got a very low C in a course as an undergraduate. And things worked out OK. The course?  Introduction to Geophysics…

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