Alphabet soup

Why are the grading rubrics alphabet soup?

When coming to physics for the first time, students are often confused by the grading system. Instead of getting a quiz back and knowing that you have 80% which would translate to a B-, you instead recieve back a series of letters. What does HGT mean, and why is it so perverse? Often students are upset at the way that the grading takes place, and that it takes an effort to figure out what the grades mean. In every other course in the university they simply tell you what you get - why should physics be any different?

There are actually reasons for doing it, and in the end it benefits students. But because we are doing something different, the burdern falls on us to explain ourselves.

It allows a transparent grading scheme
The rubrics allow you to look at your quiz and see why you obtained the grade you did (or if you did not recieve the correct grade). Simply getting 75% on a quiz does not tell you this, as it does not tell you what the grading scheme is. Contrary to popular belief, unless you get the answer exactly right, there is no objective answer to the question of how much partial credit you can get.
It forces people to look at mistakes
The idea here is that if you know you get a B- then you may say "good enough", and not check the rubric online to see what you did incorrectly.

Both of these points are to your benefit. If I ruled physics 7, I would not care so much about the second point but that is because I am mean. That is, I do not want to "trick" or coerse people into learning. I will make the information available about errors on the quiz, and if people don't choose to avail themselves of this information, then the choice (and the consequences) are theirs alone.

The people in physics 7 are somewhat nicer than I am, and choose to hand back a grade that is meaningless without referring back to the rubric. They fail at this: after a couple of quizzes students know what the best letter is, and they decrease running through the alphabet. If implemented correctly, the letters should be essentially random (with the caveat that if a letters like "I" and "T" are being used, as an I can easily be made into a T the I should be worth more). However, this method is being employed for your benefit.

It would be wrong to suggest that this scheme is a panacea - it isn't. It becomes a lot harder to issue partial credit because a rigid grading scheme cannot take into account all the ways of answering a question. But no grading system is ever perfect. Hopefully in understanding the reasons why grades are issued this way, you will be less frustrated with this aspect of the course.

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