School grades are in the news … again! The phrase that set me off is:”
… a traditional A-F grading system in which the F range is often 50-60 points while all other grade ranges are 10 or fewer points.”
Why people still use this range is mysterious, but of course I have my suspicions. When introducing a new class to my grading system I asked what grade a student would have were she to get two perfect A scores (100/100) and then being dog sick for the third test got a zero, an F. Most students shouted out something sensible (high C, low B) while as usual other shouted out nonsense. If one takes an arithmetical average of 100, 100, and 0 one ends up with an average score of 67. This score qualifies on the “traditional grading scale” as a D, just below the C range. Intuitively, the average of one A and one F should give a C, but with this system two As and one F give a D. Clearly something is wrong.
Obviously I stacked the numbers in this example to expose the flaw. How I “fixed” this basic flaw in the “tradition grading scale” is I took the tale of the Bell curve, off of 50 where it lay, and dragged it over to zero. This gives grade range scores of:
A–100-83
B–82-67
C–66-33
D–33-16
F–15-0
These numbers were arrived at by using standard deviation splits off of the standard Gaussian curve. Students were delirious with joy. I pointed out that in my example (above) the student’s average score would be a B–, which intuitively seems right. But I also told them what the ramifications were. Whereas other teachers scoring an example might look at an answer to an essay questions and see clear evidence of tear drops, might score that a 6/10, whereas I would give it a zero, with maybe a “nice tears” comment (that’s a joke, please do not flame me). My score is an indicator of how far you got to a correct answer using the path you chose. If you chose a long, convoluted path and got half-way down that path, you got a 5/10. If you chose a short route and got half way, you would also get a 5/10. If the two of you compare answers, you might be puzzled as one answer clearly involved more work than the other. But my thinking is that was your decision, not my request. You chose a longer way to answer the question that consumed space and time, but didn’t get you where you needed to go.
I was not an ogre. I modeled what 10/10 answers would be for a great many test questions asked on previous exams. (I also told them I tended to include one of these recycled questions on their exams and the well prepared got a high score as a gift.)
So, why is the flawed, clearly flawed, “traditional grading system” still used? I think at its core is a teacher’s delusion that students learn a sizable fraction of what we try to teach them. (Gosh, to think less is to hint that we aren’t all that good at teaching!) So, to demonstrate “average” learning they needed to get a score of 70-80 percent of the possible correct answers. It is clear from research, however, that that assumption only flatters teacher’s egos as students do not absorb high percentages of what they are taught. And because the system is way over balanced (a score of zero on the first test, needs three perfect scores to get an average, 75, that would give the student a grade of B) teachers make up bullshit rules to hide the flaws. For one, when they are grading you need to leave an answer blank to get a score below 5 or 6 (any drivel will do), leading to students thinking they did better than they actually did in answering such a prompt. If there are multiple quiz scores, some teachers will throw out the lowest score before averaging them, and so on.
The latest “outrage” in this discussion is the assigning of zeros for grades, when the 100 point scale is used. One state is considering a bill outlawing the giving of zeros. Some institutions are suggesting scores of zero be dropped out before average scores are calculated. Obviously these do not address the flaw in the “tradition grading system” of having ten point ranges for As, Bs, Cs, and Ds and a sixty point range for the Fs. A score of less than 50 is actually off of the curve and is meaningless, well, meaninglessly nasty. But what score does a student earn for “no response” or “off topic”? Should those not be scored with zeros?
As usual, these reformers are missing the point, expending energy trying to fix incongruities rather than fixing the system that causes the incongruities. And I think the main motivation is that teachers cannot accept that the average student learns from a third to two thirds of what they are requested to learn, which is what my system is based upon.
Uncommon Sense 