Curving vs. Canadian Grading System

[danaeris]

When I was in high school, grades were like so:
A 80-100
B 70-80
C 60-70
D 50-60

My learning experiences were all in Canada and then at MIT, both which, from what I hear, have higher standards and a more difficult course load than your average learning institution. For that reason, I'm concerned that inevitably, I will teach at that level (hopefully, the one I experienced in high school). When you consider that my students are historically weak at math and science, there comes a concern that the standard grading system at my school is too harsh for the material being taught.

Canada compensated for this difficult material by having the different grades range outlined above. MIT compensated by putting everything on a curve, usually B/C or B centered.

Anyone have opinions on which method is superior for my situation?

FYI, grading ranges at the school I teach at are:
A 90-100
B 80-90
C 70-80
D 65-70
F < 65

Comments

re: grading schema

[etherial.livejournal.com]

My school decided it didn't want to have A+s. I am pissed. Curves, at best, are for lazy professors. At worst, they unfairly much the grades around.

Ultimately, the question is simple: Do they know the material?
On a scale of 1 to 5 (5 being the highest):
5 is an A. Above expectations
4 is a B. Proficient
3 is a C. Sufficient
2 is a D. Insufficient
1 is an F. Negligible

[auror.livejournal.com]

My high school had something like this:
80-82 B-
83-86 B
87-89 B+
90-92 A-
93-96 A
97-100 A+
Where you'd get to round up fractions, so a 89.5 is actually an A-

The advantages of this was that the students were able to easily calculate their grade in the class without having to know the curve or anything else. This was cool cause then if you kept track of your grades on homeworks and tests and kept the piece of paper saying how things would be weighed (33% of grade is homeworks, etc) then you could know EXACTLY what should end up on your report card.
This also meant less parental calls to teachers about discrepancies in final grades vs grades all year. Though you might say it's harder for teachers to make up tests that many people didn't get 99+ or do very badly, however we were white rich preppy town. That means that the teachers always erred on the side of grading everything too high. Except for the chem ap and physics ap teachers. They were cool :)
So you can imagine the tests and stuff were easy. However, I still remember one time when two girls memorized the order of letters to bubble in on a scantron sheet from the previous year's test. Sheesh, they coulda just studied. (and yes they got caught and no the school didn't do anything)

[ebenezer.livejournal.com]

Statistically, it always makes the most sense to have what you call a "curve", which is actually just an allocation of grades in a manner that corrects for inconsistency in testing. This isn't about "lazy professors" -- it is not possible to know in advance (without some sort of clairvoyance) whether a test consists of questions that are (a) not the correct difficulty level, or (b) arranged such that there will be too much or too little variance in grades. A "flat" marking scheme doesn't make much sense in this context -- not only will you end up grading inconsistently, but you will have no means of balancing the value of the individual component subscores that constitute the final grade.

Whether your students are weak or strong, statistical scoring around a center and a standard deviation is almost always the right thing to do, unless your class contains a very small number of students. In that last case, a flat grading scheme still doesn't make sense, but in fact it would probably be best for you to perform personal, subjective assessment.

If you are concerned about keeping your grades consistent from year to year as well as within a particular class, then you would probably want to use some sort of sampling of how students across years performed on various individual questions to determine a scale factor. You could probably even use regression analysis for this, but I haven't thought enough about the details to say exactly what you would have to do.

Summary: "flat" grades are just a hack. There are several reasons, each valid, for which you cannot expect to derive a useful assessment that way.
Maybe I say this because teachers at my urban public high school graded everything on a curve too, but believe me, they had some good arguments for doing so.

[auros]

What if the distribution of skill in a class does not actually follow the shape of your selected curve? In order to compensate for cases where one or two students outperform expectations, at a scale that "blows the curve", you're going to need a certain amount of subjective fudging. Either that, or you have to invest the effort in creating a test that you believe, on a flat system, will accurately reflect whether students have learned the material. *shrug*

[ebenezer.livejournal.com]

Provided that the scaling function is implemented correctly, subjective fudging is only necessary when the number of students is too small. Contrast this with a flat scheme, in which subjective fudging is necessary in not only this case, but possibly all others as well.

Also, the "blowing the curve" phenomenon is the result of teachers implementing the curve incorrectly. What you want is to center the scores around the median (not the mean, not the highest score in the class!) and then scale them such that one standard deviation is worth a fixed number of points.

AP chem

[vokzal.livejournal.com]

Was graded on the square root curve.

[tunape.livejournal.com]

My HS had a tough grading scale:
95-100: A
90-95: A-
87-90: B+
83-87: B
80-83: B-
and so forth

I believe that it is fine to have a tough grading scale as long as there is a supportive environment for the student to succeed. My HS was a "magnet" school(IB and AP), and eveyrone knew it was tough. However, teachers were there to go the extra mile to help you, and they truly cared. Not everyone got A's, but everyone succeeded in learning - I think that's what's most important.

I've also heard of personally-adjusted grading curves where it is based on how much the student improves. Even the best student who can crunch numbers better than MatLab can get a B/C if he/she does not learn and improve.

[plymouth.livejournal.com]

My public school was graded on the same flat scale. Only once did I take a test where average was a D and the highest score was a C+. The teacher refused to scale it, insisting that it was all material we should know in order to pass. That was the only C I got in my entire high school career, so I was pretty blown away by it. I'm still not sure if the teacher took the right approach or not.

[tunape.livejournal.com]

I received my share of C and B's in HS, but some teachers made me want to improve and get better. Like danaeris, ended up at MIT. I noticed, however, that it was the less experienced teachers who tended to give tests which were horribly out of reach of the students(that, or they did not teach well). Not to imply that Dana does not teach well, but just pointing out that the experienced teachers who have 10+ years under their belt know where to draw the line between something impossible for the student, and something which is a breeze. The very good ones will always challenge the students a little bit more than what they can handle and show them what more there is to be had.

Teaching is probably one of the hardest jobs! Good luck, Dana! ;)