Curving Grades Yes or No?

[HigherEd7]

I know some teachers curve grades, and some people don't. I played around with it for the first time on Canvas, and it bumps up your student's grades, but it is fair to the rest of the students who have done the work, etc..

I also heard some teachers will give a few points to a quiz or exam to help the student out just in casquestions areons are a little hard.

My question to the community is: what is the best thing to do and what is fair to the students? In the past, I just dropped the lowest quiz grade.

[Ruralguy]

Whatever you want, as long as you are consistent and explain yourself well. That is, don't do different things at different times sort of randomly.

Of course, I'd warn about making too many gifts as that will not encourage studying and hard work upfront.
Also, check against department and college culture in terms of norms for this sort of thing.

[Parasaurolophus]

I don't see the point, personally. If I'm trying to be generous, I'd rather drop the lowest grade, since that won't ever hurt anyone.

[HigherEd7]

Thank you for the responses! Make sense

[Hibush]

The phrase "curving grades" is often used to mean a lot of different things, many of them nonsensical or unfair.

The original use of curving refers to the statistical Normal distribution. It assumes you have a large class and that their performance on a test will be distributed according to the Normal distribution, and that the each time you teach the class your students in aggregate perform the same. If there is a difference in scores from previous courses, it is due to differences in the questions or grading, not to a difference in the students' ability. It is rare for all those assumptions to be true!

When you do curve that way, you decide the grade distribution before the test is given. In fact, it should remain the same as the previous times the course was given. For instance, the standard may be that the highest 20% of scores get an A, the next 30% get a B, the next 40% get a C and the lowers 10% get Ds and Fs.

This approach is probably excellent in large first-year intro chemistry and intro calculus. Especially if the test has to be changed a lot to counteract cheating.

A better approach is to design the test so that particular scores map to particular levels of mastery that you decide in advance. You can associate those levels of mastery with letter grades. When you do that, the students can vary from year to year. Everyone could get an A. Or an F. If that is the appropriate grade.

[EdnaMode]

I have found that when students ask if I'm going to "curve" an exam, or overall grades, what they really mean is am I going to change the grading scale so, for example, a 70% is now an A instead of a C, and the answer is no. Every semester, students are different, sometimes nearly half of a class earns an A or B and no one fails. Other times, in a different section of the same class, taught very similarly, there are only a handful of As, a few Bs, lots of Cs, and more Fs than I would like. I record what the students earn, and the only thing I ever do that might resemble a curve is to round up the .9s, for example, a 79.9 would round up to 80 and a B- instead of a C+ and if I round up for one, I round up for all. 

[fosca]

If I thought I made a mistake in testing/grading, I'd just as soon fix that (I've thrown out questions that had issues, or added a certain number of points to everyone's grades).

I also let students know that the mode in my class is generally a B, and if I curved I'd have to make that a C, which would lower the grade for as many (if not more) students than it would help.

I had a student ask me about curving over the summer, and I pointed out that 1. the reason people didn't do well is because they didn't follow the instructions, which is in no way my fault; and 2. if I curved one I'd have to curve them all, and he'd likely then have his grade lowered because of how he was doing.  He didn't ask again, and wound up getting an A (I drop lowest everything and have some extra credit for borderline cases and I round up like crazy).

Then again, in first-year Calc I was given a C, when I didn't pass any of the tests.  But my class isn't that brutal.

[Sun_Worshiper]

I don't see the point, personally. If I'm trying to be generous, I'd rather drop the lowest grade, since that won't ever hurt anyone.

Same.

[jerseyjay]

As has been noted, when students ask if I am going to curve grades, they usually mean, am I going to do something magic to the grades so that a 75 per cent really equals an A. I don't think that many (especially in humanities courses) understand what a curve is, and I think that many would be offended by the concept that you all students should fall into a bell curve and that a certain percentage of students should fail.  (I do think that it would probably be useful to require students to take a basic statistics class, but that's another issue.)

I personally have never curved my class. I do not structure them to create a bell curve, but I also do not often use many objective exams. (Among other things, this raises issues of reliability.)  I do not see my students as competing against one another--it is possible to have all students get As, or all students get Fs. More frequent is a bi-modal distribution, with most students getting either high or low grades.

One form of "curving" that I have done at times is to set the highest grade on an exam as 100 per cent. This has the effect of essentially adding points to everybody's grade. I have done this when a section has en masse done worse than I think that they should have (i.e., even the higher performing students have got relatively lower marks). Although I have already said that it is possible in my classes for everybody to fail, if I think the class is working well, and even the best-performing students do not get As, then I am more prone to think that there might be something wrong with my assessment (or my scoring) rather than the students.

[HigherEd7]

If I thought I made a mistake in testing/grading, I'd just as soon fix that (I've thrown out questions that had issues, or added a certain number of points to everyone's grades).

I also let students know that the mode in my class is generally a B, and if I curved I'd have to make that a C, which would lower the grade for as many (if not more) students than it would help.

I had a student ask me about curving over the summer, and I pointed out that 1. the reason people didn't do well is because they didn't follow the instructions, which is in no way my fault; and 2. if I curved one I'd have to curve them all, and he'd likely then have his grade lowered because of how he was doing.  He didn't ask again, and wound up getting an A (I drop lowest everything and have some extra credit for borderline cases and I round up like crazy).

Then again, in first-year Calc I was given a C, when I didn't pass any of the tests.  But my class isn't that brutal.

If you added a certain number of points how many points would it be? For example, if you are giving weekly online quizzes.

[fishbrains]

I have occasionally added points when I've screwed up with a bad question or a new essay prompt that just wasn't as good as I thought it would be. It just depends on the situation. I don't want to hurt students because I got creative for some reason.

Very rarely (maybe twice in the last twenty years), I've added points to everyone's course grade because of events beyond everyone's control. Once was a state government shutdown where we lost a week or two of a summer course, and once was a series of winter storms that closed the college and knocked out power in parts of the region for well over a week at the end of the semester.

[the_geneticist]

"That word.  You keep using that word.  I do not think it means what you think it means." Inigo Montoya, The Princess Bride

What student want is for you to lower the cutoffs for each letter grade and/or give folks more points. I've never needed to, but my class has a lot of formative assessment points that are easy to earn.

I do have colleagues that routinely lower the cutoffs.  The students think that it means it's going to be easier to get an A if anything over 75% is an A.  Poor students don't realize it means that Professor [>75% is an A] writes DREADFULLY hard exams.  And there are no formative assessment points to bolster your grade.

[mythbuster]

As an example of what The Geneticist means. I took Organic Chemistry as an undergrad. The prof I had aimed for the averages on his exams to be 50/150. Yep- 33%! If you scored above a 75, you were an organic chemistry genius. As a result, these exams were HEAVILY curved.  To the point that I'm not sure how anyone truly failed. But that's another issue.

I've also heard stories about imposed curves, at Princeton I believe, to curb grade inflation. No more than 10% of the class was allowed to earn an A regardless of scores!

Both approaches are wrong headed. I apply some gentle grace nudging at the end of my course for those on the line (within 1 percentage point) between grades. But otherwise, I aim to build a class that doesn't need any "curving".