Can someone explain how grading on a curve works? The whole time I was in college I never quite understood the relationship between exam scores (in percent) and GPA (with a 0.0 - 4.0 range). I don’t know if GPA scores are intended to fit the normal (i.e., Gaussian) curve, but I always used to think they did. I had the vague idea that 2.0 was supposed to be the average and the Standard Deviation was supposed to be 1.0. That way, about 2.3% of students would get a 4.0 and another 2.3% would get 0.0.

But if a system like this were in place, grade inflation would be impossible, since your GPA would depend only on your rank compared to other students in the class. Was it the case that the system described (or something similar) was the original curve, and that it has been changed to give more students As and Bs and fewer Cs through F?

I found the curve used by the Case Western Reserve University School of Law and it is by no means symmetrical, as the normal curve is. The five highest grades (A to B-) constitute 80% of grades given. The five lowest grades (C- to F) constitute only 5%.

There’s a few different ways that grading on a curve can work. In technical classes, such as math and the sciences, the practice usually consists of fitting grades to a Gaussian of some sort. Usually, this is only done in large lecture classes, as 20 students or so isn’t a large enough sample to be statistically significant. Of course, many non-technical teachers don’t know enough statistics to use this method anyways, so there’s other methods. One common method is to count the highest score in the class as perfect, so if the best score was, say, an 83, then everyone else is scored out of 83 points, not 100. Another method is to add some constant to everyone’s score such that the average comes out to whatever number the teacher wants.
The way that grade inflation comes in, is that the teacher chooses what the average should be. It used to be that 2.0 © was the average, as you said, but it’s becomming increasingly common for the average to be set to 3.0 or higher. Grade inflation can also occur outside of curving through various methods. The professor I graded for last semester, for example, insisted on students being given at least half credit for effort on homework problems, and at least passing for labs where they showed up, regardless of quality of work.

GPA is not related to curve-grading other than as a representation of the final result.

On a 4 point GPA:

An F = zero points
D = 1.0
C = 2.0
B = 3.0
A = 4.0

Most colleges multiply the number of hours credit by the grade point before dividing by the total number of hours to obtain a Grade Point Average. For example:

Let’s say in an average semester, phouka the art student takes:

3 hours Sculpture
3 hours Art History (prehistoric through classical)
3 hours Figure Drawing
3 hours English
3 hours History
1 hour Kinesiology (archery)

My grades for the semester were (fictionally) as follows:

Sculpture: B (3.0 GP)
Art History: B (3.0 GP)
Figure Drawing: A (4.0 GP)
English: A (4.0 GP)
History: A (4.0 GP)
Archery: A (4.0 GP)

Sculpture: (3.0 x 3 hours) 9
Art History: (3.0 x 3 hours) 9
Figure Drawing: (4.0 x 3 hours) 12
English: (4.0 x 3 hours) 12
History: (4.0 x 3 hours) 12
Archery: (4.0 x 1 hour) 4

Total Number of Hours: 16

GPA for the semester: (Total Cummulative Grade Points divided by Total Number of Hours) 3.625

The grade inflation thing is terrible tho. I got a 3.0 ave, which was considered very good. In my HS senior class, there was one girl who got a 4.0, the first in 3 years. There was a major too-ra, and she was on the front page of the local paper. 20 years later, that same paper had a list of 40 students with a 4.0.

I used to teach at the University of North Carolina and at a community college. I always reserved the right to “curve” any particular exam, and add a final curve at the end of the semester if necessary.

I took the approach to challenge my students. Of course, they tended to whine a lot (“that test was hard!”). If a particular test had an average of, say, 62, with a class high score of 89, I would probably add 8 points to everyone’s test. Class size, subject, and level were always considered and treated in different ways. The main thing is to be internally consistent within any given class.

Of course, many teachers tend to think the best exam is one where the final spread is 75% of the students above an 85. To me, this test is not challenging enough to separate who really knew the material vs. who lucked out on an easy test.

At the end of the semester I would analyze the final averages and look for natural breaks in the distribution. Any additional curve could only work to a student’s advantage. That is, I always used a 10-point scale. At times I would maybe group the 87s-89s in with the As; but I would never ‘scale up’ to make the lowest ‘A’ a 93 or something.

As a student, I had professors use all sorts of curves. A curriculum in the hard sciences tends to lend itself to a whole lot of low scores. One physics professor used a factor based on the class average. Let’s say the exam average was a 57. To scale to 70 you would need a factor of 1.228. Then, everyone’s score got multiplied by 1.228. So, if you originally got a 95, you would end up with a 116.7! Of course, if you got a 30, you ended up with a 36.8. Rationale being, why would someone who blew off the test deserve the same points added his score than someone who truly achieved. A case of the rich getting richer.

And all this is aside from grade inflation. Any lower level class where 75 get As and Bs is, IMO, too easy. It is different when it comes to upper level classes and graduate school. Anyone who gets to the upper levels of one’s specialty should be proficient enough to get at least a ‘B’ in most cases. Introductory classes do no favors for anyone if the right people aren’t weeded out. Hey, how else do you know that med school isn’t for you if you cruise through Zoology 1001 without really learning anything?

Boy, I’ve rattled on and still haven’t begun to scratch the surface on the grading situation in higher education. I have lots to say on this subject.

I liked Pirsig’s idea of the college with no grades. You were there to learn, not compete with the other students. You got feedback from your professor, but nothing was “scored”.

I dropped out of school after 11th grade because I wanted to learn, not regurgitate professors’ opinions and win a game I wasn’t interested in playing. I have taught myself history, mathematics, science, literature, politics, and philosophy.

Life is the ultimate graduate school.

Sheesh, SingleDad, you’re a dropout? I must say, it sure has worked well for you, you’ve got to be one of the most knowledgeable folks on the board! That said, though, I’m in school to learn, too, but even if I know that I’m learning, the grades are still necessary to let everyone else know that I’ve learned. If there weren’t grades, and a couple of folks who’d sat through the same amount of classes tried to get a job, how would you know which one actually knew his stuff?

chronos, dear friend, that’s why they have interviews, to weed out those who just sat through the class and those who did the work. i’m in the same boat right now (at a “prestigious” university where the classes are killing us all and the profs feel the need to overcompensate for what they see as grade inflation on the part of some of their colleagues). last week, an interview for an internship went like this:
interviewer: i noticed that you didn’t do so well in your language class this semester.
me: yes sir, it was very difficult. it was a graduate level class and the material was accordingly fast paced.
interviewer: i see. what do you think about the current political situation in japan?
me: (five minutes of opinion on the current situation).
interviewer: i see. well, i must say, the grades don’t say much.

the interview was conducted in japanese. i got a c in my japanese class last semester. the man didn’t care, as it was obvious, c or not, that i had done the work.

so, have no fear – when it really counts, grades don’t matter, knowledge does.

one last note: a professor of mine once told us a story about how his daughter had failed every physics test she took in high school, and, because of grading on a curve and some serious grade inflation, took honors in the class.

one more last note: the old guidance counselor standby line is still in effect in college – it really does matter the difficulty of the classes you take and where you take them, not just the grades you get.

And the problem with this is that it is impossible to identify the truly outstanding students. Your friend of twenty years ago would have been just one of 40 4.0s.