The grading system needs a rewrite -

The grading system needs a rewrite

Professor Pettigrew proposes an entirely new system


Photo courtesy of j / f / photos on Flickr

A few years ago, a colleague told me that when he was a TA, he was told never to give a grade below 45. The reason was that students earning a very low grade would dig themselves into a hole and wouldn’t be able to pass the course.  At the time, I scoffed at such a practice. After all, it’s unfair to give a student who did next to nothing a 45 when another student who just fell short the same 45. And what if the student doesn’t turn in the paper at all? A 45 for nothing?

Another way to view this problem, as Douglas Reeves has argued, is to note that the standard A, B,C, D, F grading system over-punishes missed assignments which get graded at zero. Actually, it’s worse: any serious failure is systemically unfair because the F range is, compared to other grades, huge.

Still further, the traditional scale forces professors to grade with a very narrow range. Most papers are somewhere between D- and B+, a range that uses only thirty points (50-79) out of one hundred.

The solution is to revise the percentage system to equally distribute grades over the whole range from zero to one hundred. We change to old system:






to a new system:






Now, I’m not suggesting that a failing paper that used to deserve a 40 under the old system would now pass. What I mean is that the paper that deserved a 40 under the old system would now be given a 16 in the new system. The numbers are different but represent the same thing, just as 0 Celsius is no colder than 32 Fahrenheit.

The new system means that one disastrous failure or one missed assignment in an otherwise decent performance doesn’t cause a student to fail the whole course. For instance, imagine a student, Mishrump Middleton, who has four equally-weighted assignments in his course and earns a C- on the first three but fails to turn in the last one.

Mishrump is no Rhodes Scholar, obviously, but he probably doesn’t deserve to fail the course. But, under the old system, Mishrump gets a 45 as his final grade —  an F — and fails because that single zero drags him down. But under my system, Mishrump gets a 30 which, remember, is now a D and so still gets credit for the course, which, intuitively, he probably deserves. Put another way, Mishrump gets the equivalent of the old 55 instead of the old 45 because the grades are more logically distributed.

But how can I use my new system? I can’t simply give a C- student a grade of 40 and expect everyone else at my university to know that what I mean by 40 is not the same as what they mean by 40. And even if I could get my whole university to switch over to my system, it might be confusing to others if Cape Breton University’s transcripts showed a middling student with a 45 average instead of a 62. The whole country will have to make the switch.

In the meantime, I have a solution for my own classes. I will give students letter grades but calculate their grades using my new scale. Then, at the end of the course, I will translate those grades back into the standard percentages. It will be more work, but it beats giving every failing paper a 45.


The grading system needs a rewrite

  1. What the hell is this?

    60-79 gets you a b? are you nuts? You have a 20% gap there. You make no sense at all.

    I was also a TA. FYI, students are not prepared for University and most of them are not smart enough to do well in school. Life sucks, what are you going to do.

    • Did you even read the article? I am not sure you have the grasp of math your name suggest. Perhaps you should consider another career path because you attitude indicates someone who isn’t suited to work in education. Perhaps you should become a career republican in the US.

      • Ummm . . . maybe my grasp of math is bad as well but 60-79% is 20% because it is inclusive of its highest and lowest numbers (i.e. 60=1, 61=2, 63=3 … 77=18, 78=19, 79=20).

        And may I suggest you undergo some sort of anger management … or at least charm school. Your reaction was quite harsh and overblown.

  2. “Life sucks, what are you going to do.” Can we make that our university motto?

    Seriously, though, I think this might be like trying to change the QWERTY keyboard layout, or introducing phonetic spelling. The status quo is poorly designed and causes problems, but everybody uses it, so it’s too unwieldy a change to implement across the board.

  3. It seems to me that this system would work better for written assignments than for multiple choice problems and some of the “harder” sciences.

    When I grade written assignments, I read them, give them a letter grade, and then see what number that letter grade corresponds to (So, I read a paper, give it a B, and then punch it in on a spreadsheet as a 73%). But the numbers don’t really matter for anything – all they’re really used for is to make it convenient to calculate final grades, which are expressed back in letter grades anyways.

    However, for multiple choice problems and things like engineering exams, they tend to be graded on a number-grade system, where the number represents a discrete question whether you got right or wrong. So, it goes the other way around – you mark all the multiple choice questions, add them up, and come out with a number, which you convert to a letter grade once everything is tallied up. Here, your system would break down because it would mean that a student who got onlt 25% of the questions right would still pass.

  4. This system would do little more than play to the mean. The penalty for have a zero or a very low mark in relation to other marks in a course is certainly high: it should be. The fact is that These sorts of major failures need to have major consequences.

    Though some students are motivated by scholastic challenge, quite of students, especially middling students need some sort of negative reinforcement or consequence in order to ensure that work actually gets done. If Mishrump were able to pass the course with three C-‘s and a complete no show on the last assignment, what do you think that would tell him about the effort that is expected of him?

    We already have enough problems with grade inflation and falling academic standards. This new system, though hypothetical, is the last thing that we need.

  5. Doug Reeves calls the zero the academic death penalty. I agree. What if the scale only went to 50, so 50 was the new 100. 0-10 would be an F. 11-20 a D…this way educators who feel the need to give zeros can still do so. The conversation should revolve around educators who don’t want to work in a system that creates opportunities for success.

  6. If this new proposed system were to take over, all I can see here is that a student who would have had to re-take the course to learn the material will now graduate with the same diploma or degree as someone who paid attention, did the reading and did the assignments, and did well in the class.
    While this might be more agreeable to the slackers in the class, it’s an insult to the students who really do have an aptitude for the material and a willingness to study.
    What would this do to the reputation of the school? Well, would you want to hire someone who did well, or the person who should have failed? Who do you think is a better candidate for post-graduate studies? Instead of coddling students who don’t understand the material (or aren’t willing to put in the required amount of work), how about encouraging them to find more suitable fields of study?

    However, if this is just in your class alone, then a student might feel “hey, I’m doing ok… I’m getting Cs”, and then be blown over when he or she (appropreatly) fails at the end of the sememster, since the standard of work WAS below average; below expectations.

  7. May, I think you’re missing an important point here. A paper that normally receives a grade of 0-49 will be mapped to a range of 0-20. A paper that normally receives a 60-69 will be mapped to a 40-59. The main effect of this system is reducing the amount of damage that a zero does to your score relative to the increase received by getting a 100%. Under the current system, if you have a zero and a 100, then they average to a 50–a marginal pass. Under this system, if you have a zero and a 100, they still map to a 50, but that 50 is now a C, not an F. Which is still less generous than the alternative, setting all Fs to 45, which means that a 0 and 100 are averaged to a 72.5–a B. The figures he is giving aren’t percentages; he isn’t suggesting that students receive higher grades for lower quality work. This is purely a different way of scaling the results of student work into letter grades.