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[International Teacher]

Hi,

I am new in the US higher education system.  After every test, my students want to know if the grades are "curved".  

What does it mean?

 And why or under what circumstances will a teacher "curve" a test/exam?

What are the implications of "curving" a test/grades?

thanks - IT

[desert rat]

At my campus, it generally means one of two things:

1.  Give everyone a set number of "extra" points.  For instance, give everyone 10 points, so that a grade of 72 is now magically an 82.

2.  Lower the cutoff scores.  For instance, a grade of 86% might be an "A", 73% might be a "B", and so on.

DON"T DO IT!  At least until the end of the semester.  Students won't complain if you give tham a higher letter grade than their average, but you can not give them a lower grade!

[2 More Cents]

The reason it's called "curving" is because it technically means distributing grades approximately along a bell curve.  This, of course, is not what student want, as desert rat explains.  When I'm asked about curving, I tell them they don't want me to curve grades since that would guarantee that some of them would get F's no matter how well they did.

[Dr. Curve]

Well, I usually let students choose. A true curve would mean that there would be a bell shaped distributions of grades, mainly Cs (about 68%), some Bs, and Ds, about 12% on each side, and then some As and Fs, again about 5-7% on each side. Once they see how true curving works, they'll never ask for it again.

[Zarkov]

There are at least a couple of approaches (or philosophies) for grading.  Grading on a curve reflects relative performance, perhaps along a normal distribution, as a previous poster explained.  Another approach is to see grades as a reflection of mastery of the material. With this mastery approach, a whole class could get As -- or Cs -- depending on how many people mastered the material.  (Perhaps you could say mastery reflects absolute performance.)

In practice, I think many of us combine the two approaches, perhaps without thinking about it two much.

PS:  Here is a very simple way to grade on a curve.  Say a quiz or exam has 25 questions.  Figure the average correct and call it a BC or C (say). Rank the better tests up toward an A and the worse ones down toward a D or F.  You don't need to calculate percents, just give the best tests As, the averages Cs, the ones between A and C are Bs, and so on.

[anon]

I don't curve at all.  My students receive the grades they earn.  They have so many possible points, and their grades depend upon how many points they accumulate.  If I had a whole class full of students who were doing poorly, I might consider curving.

[k16]

The alternative term you'll probably here is 'scaling' the grades, which is essentially what was described above, rather than putting the grades into some sort of bell curve.  As to whether to do this, find out what is expected at your school, and do not go significantly against it.  Sadly, 'grade inflation' is normative at many campuses today, and if it is at yours, and you do not engage in it, you may well find your services no longer required.

[Somewhat Amused]

Curving is usually a result of poor planning or the complete lack thereof. As others explain, the instructor artificially creates a "bell curve" to simulate normal distribution after the fact. It is wrong for a great number of reasons, some of which are listed below:
1. Poor or no planning; consequently, the grades are skewed in one direction (usually too low or too high); merely a band-aid approach.
2. The level of the course is inappropriate, but instead of sticking to a pre-set standard, the instructor decides to fix things once grading has occurred.
3. The instructor takes on the role of the "tough guy" initially but later chooses to "ease up".
4. Curving may have the unforutnate side-effect of pulling some of the good (not the best) grades down (depending on the original distribution).
5. Curving also has the unfortunate (often intended) effect of pulling bad grades up. Basically, too many students may be failing and the instructor does not want to stick to her/his standards.

Be consistent. If you are tough, be tough, but the students deserve to know where they stand and what they can expect. Curving is unprofessional and a hallmark of inconsistency. Avoid it at all costs. If you plan well, there won't be a need for curving.

[Zarkov]

FWIW, grade distribution reports are available with many/most of the grade software database systems, so chairs and administrators can (and DO) monitor each prof on his or her grade distribution.  Thus, if one is too "easy" or "hard," then it will show in the numbers, and the prof might be spoken to. (And be a negative when it comes to tenure or contract renewal time.)

[bennyhaha]

When I see profs or instructors that have curved it tends to be because their exams were more difficult (or often more confusing) than they had meant for them to be, which resulted in a really low mean/median exam score.  If this is the case, then it's something that really shouldn't happen from semester to semester, as tests can be revised.  

I explain to students that I do not curve their grades but will adjust for 'bad' questions.   This would probably be difficult to do without a computerized testing service, but I receive reports that tell me what % of people in the top and bottom half of scores chose a certain answer for each question.  If it appears that the "good" scorers were confused by another answer, I'll go back and read over the question, and possibly throw it out.  For a tossed question I give everyone a point, so that even those students that got it right simply get an extra point.  This usually happens with no more than 1 or 2 questions and it keeps everyone happy, and I don't have to curve anything.

[kif]

For exams, I frequently "curve" (not really) grades by increasing everyone's score by the factor required to increase the top score to 100%.  For example, if the best score in the class is 92/100, I multiply everyone's grade by 1.09 since 92 x 1.09 = 100.  My rationale:  I'm bold enough to assert that my teaching got at least one student to the point of getting a 100 on the exam and humble enough to admit that my test may be imperfect.  Sends a good message to the students, I think, and cuts way down on whining, but I've never had it make more than a minute difference in the grades.  Frequently, it makes no difference since someone will get 100% to begin with.

[%sig%]

[Dr. Evil]

I had a group of students ask for a curve once.  After I explained that it could lead to grades dropping in some cases, they said, "You can't do that!  That's like the anti-curve."   It did get them to stop asking though.

Personally, I never promise a curve and rarely have one.  The point is for them to prove they have mastered the material, not to be sure I have a "proper" grade distribution.  I have, on rare occasion, had quizzes end up being harder than I thought and adjusted scores, but I try hard to avoid that.

[don't like curves]

anon wrote:

> I don't curve at all.  My students receive the grades they
> earn.  They have so many possible points, and their grades
> depend upon how many points they accumulate.  If I had a whole
> class full of students who were doing poorly, I might consider
> curving.

If I had a whole class of students who weren't doing well, I'd reassess my teaching. If a course has to be curved to the point that someone with a 70 has an A (as happened to me when I was an undergrad), then the instructor is teaching over the students' heads and needs to redesign the course.

[Al Bundy]

don't like curves wrote:

> > If I had a whole
> > class full of students who were doing poorly, I might consider
> > curving.
>
> If I had a whole class of students who weren't doing well, I'd
> reassess my teaching. If a course has to be curved to the point
> that someone with a 70 has an A (as happened to me when I was
> an undergrad), then the instructor is teaching over the
> students' heads and needs to redesign the course.

In one situation I had more than half of a class receiving D's and F's on a test, simply because I had a terrible group of students (to put it bluntly, a bunch of retards). I had taught the same course several times before, and never had that problem.

I refused to "curve" the grades and reward homogeneous mediocrity, and gave them the chance to take the test again (a very similar test, which was optional and would be averaged with the first one). They hated my guts for doing that! How dare I make them study again and insist that they learn the material, when pulling an esoteric grading scheme off the hat would be so much easier on them.

The only situation in which I scaled grades was when I gave an exam that was too long, and no one was able to finish it in time. This was really my fault---I was teaching the course for the first time, and had no frame of reference. Needless to say, next time I teach the course I'll make the necessary adjustments, and that won't happen again.

[Pretzel]

I too don't curve grades, at least not for major tests.  At the end of the semester, howver, I am somewhat generous with the borderline cases, e.g., 89.2% or, depending, even 88.9%. I also do the drop-the-lowest-quiz-score thing, which could be seen as a curve, I suppose.

Even though I consider myself a non-curver, I want to say something about it. Being somewhat of a math geek, I notice that many professors who do curve simply add X points to each student's score. I think this is unfair (I know, I know, many of you think curving itself is unfair). My point is that -- Why should the student who earned, say, 95, get 5 bonus points (5/95 = about 5%) when the student who earned only, say, 45, also gets the same 5 bonus points (5/45 = 11%).

One poster (kif) offered a much fairer solution, I think. Not ADDING but MULTIPLYING, such that the highest score becomes 100. Every student's score is multiplied by, in his/her example, 1.09. The higher your initial grade, the higher your curved grade in proportion, not simply the "plus five points" curve.

In undergrad, I had a professor who did a very unusual curve. Rather than simply giving every student X additional points, he added 1 point for every 5 points that the student had LOST. If you earned 95, then you had lost 5 points, so you got 1 bonus points. If you earned 60, then you had lost 40 points, so you got 8 bonus points. In the end, the more points you lost, the more points you got free (always in proportion, mind you). I didn't like this curve at all.

I also remember in high school, my Spanish teacher offered a bonus question on a test. I got the bonus question right, and my score went to 103. He wouldn't let me keep the 3 points over 100. I asked him if he could add it to my previous test score which was about 94 or so. He said no. Instead he let me give the 3 points to another student.

[%sig%]