The 90-80-70-60 scale... what gives?

In the US of A, it is well known that, on most tests, if one scores between an 80 and 90 percent, one earns a letter grade of a B. Ummm... okay. Why? Why not 60 to 80%? Why not some other arbitrary range?

Here is more of the "standard" scale:

• 100-90% = A - which typically means "excellent"

• 90-80% = B - which typically means "good"

• 80-70% = C - which typically means "satisfactory"

• 70-60% = D - which typically means "poor"

The last of these letters is F which typically means "Fail". Of course, that means that the F scale goes from 0% to 60%. So, you're trying to tell me that the F range is 6 times larger than each of the other ranges? Why is that?

This also means that the range for "excellent" is the same size as the range for "good". Does that make sense?

My point? These ranges seem totally arbitrary and I can see no benefit to the student or to my teaching in having to use such ranges.

This grading scale also begs the question: Percent of what? Now, in math classes, it usually means the percent of points a student has earned against the possible number of points. So, if a test is worth 40 points and I get 30 of those points, then I get a 75% and thus a C. So you're telling me that I understand 75% of what I was tested on and this is satisfactory? What if I that 75% represents the top score on the test? Then what does that mean about my "satisfactory" grade?

Even weirder is that this scale gets used in other disciplines. I write an essay in English. My essay is "good", but not "excellent", so I should get a B, I guess. But, how in the world could one possible assign a number to my essay.

Anyway, I give this post a 77%.

What the heck is this blog all about anyway?

A major focus of my professional development in the last ten years or so has been the role of evaluation in the education of high school students. Hi. I'm a high school math teacher. Want more? I am a math teacher at a prep school. At an intense college preparatory secondary school. So, kids are sent here to go to college. Or so it would seem. And I am part of that.

Now, I want my part at my school to not be just as a tool that students use to get to the next place. No teacher wants that. So, I question everything I do, and the biggest question that looms over me, especially at the end of each quarter is what the heck am I doing assigning a grade to these kids. I mean, how does giving a student a grade really benefit that student?

I wholeheartedly (yes, I mean that, with every ounce of my heart) reject the "positive reinforcement" idea. Quickly, if you think negative reinforcement is bad, then why should positive reinforcement be any better? Both are used as a means of obtaining compliance. Don't do this, or you will go to your room. Do well on this test and I will give you a token that helps you get into college. Same thing. Don't trust me, trust Alfie Kohn who exhaustively researches his writing. Check out this article first.

But, I am obligated to pursue this practice given where I currently teach. Really, this would be the case at the vast majority of secondary schools, so it's hardly surprising.

At the end of each quarter, at the end of each project, at the end of each test, and so on, I assign a letter grade to evaluate the quality of the student's work. This simple letter grade only conveys how one has done compared to one's peers. It does not offer any suggestions as to what is "good" or what "needs improvement" or if a student has improved or regressed or been stagnant. And, given the high stakes involved - Yale? Carleton? UC Santa Barbara? - students learn that these tokens are what they need so that is all they pay attention to. Yes, I am generalizing, but it is a valid generalization.

My proposal: Eliminate with great haste and with great contempt the letter grade. Evolve as a teacher, evolve as a school, and evolve as a student. Who knows, maybe evolve as a society?