On Averaging Grades
Averaging student grades doesn’t make much sense to me. A lot could be seriously written on the subject, but this post will just be a little rantish. (Note: A lot of my specific arguments here are inspired by Ken Gatzke)
Let us suppose that your class has 5 graded papers, all of approximately the same length and importance. Now consider 2 students, Andy and Ben. Andy gets the grades A B C D F on his papers, while Ben gets the grades F D C B A. If you average their grades, they will roughly come out to a C (assuming the F was within a reasonable range). However, the grades tell entirely different stories about the two students. While there’s no necessary connection between a set of grades and a particular story, let me stipulate some stories to drive home the point.
Andy did well in his previous class in the subject and understood the introductory material very well. However, he gained absolutely nothing from the experience of this class. The further the material drifted from what he already understood, the worse he did. Ben, on the other hand, started out with no background in the subject whatsoever. However, over the course of the semester through hard work and perseverance he came to understand the subject completely.
Now, what would be the justification for giving each of these students a C? It seems to me that by these accounts, Andy deserves an F and Ben an A. And while these are not the stories of most students, Andy and Ben are sure to eventually fall victim to this unjust grading scheme if it persists.
Obviously, resolving this problem would require examining what grades are supposed to do, as well as how to make them do that. As that would be a much longer rant, I’ll do the usual philosophical thing and leave the reader with a criticism and some questions - answers are left as an exercise.
4 Comments so far
Leave a comment
Hi Thom,
One option would be to weight the assignments differently.
First Paper - 10%
Second Paper - 20%
Third Paper - 30%
Fourth Paper - 40%
That may introduce other worries, but it would handle the intuition that Ben’s overall grade should be higher than Andy’s
By Andrew Cullison on 12.19.08 3:42 pm
I like Andrew’s solution on the face of it at least… I’ve had a number of teachers who would weigh later papers more, or modify the previous papers’ grading scale based on improvement over the semester. (I saw this a LOT in art and music classes and basically never in english lit, for example.)
By Buck on 12.19.08 3:50 pm
Assuming we went with this scheme, and made the 5th paper worth 50%, my calculations would then put Andy at a D+ and Ben at a B-. Possibly the right grade for Andy but I think given the stories I’ve told, Ben deserves better. And if we make Ben’s first paper a 0 instead of a 55, his overall grade under this scheme drops to a C+.
EDIT: Note that the grades don’t add up to 100% here; I’m assuming you then go ahead and divide by 1.5 or however you’d like to do the math..
By thomblake on 12.19.08 3:50 pm
Here’s an added complication to the above suggestion that might go all the way to doing what Thom envisions.
You have variable weights. If the student’s final paper represents a significant enough improvement, then you drop the first paper, or redistribute the weight between the first and last paper - so that the first paper is weighted even less than 10%
But you would have very stringent standards as to which students could get rewarded with this modification.
Your first paper doesn’t get dropped/weighted less unless you get an A.
The idea being that only super-meritorious work blots out poor performance in the past.
I already do something like this (but not as extreme). The students have two papers weighted equally at the start of the semester (plus tests etc..). When I hand back the first paper, I announce to students that they have the option of having the second paper carry more weight than the previous paper if the second paper is an improvement.
Students work much harder on that second paper.
By Andrew Cullison on 12.19.08 4:19 pm
Leave a comment
Line and paragraph breaks automatic, e-mail address never displayed, HTML allowed:
<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>