#1
Old 02-24-2009, 01:07 PM
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Grading on a curve

In your opinion, what constitutes "grading on a curve"?

For example, if a teacher applies a scale where 90-100%=A, 80-89%=B, 70-79%=C, 60-69%=D, and 59 and below=F - did the teacher apply a curve?

What if the teacher above finds his class did poorly, so he drops the standard for each grade 10 points such that 80-100%=A, 70-79=B, etc. - have they now curved the results?

How about, instead of lowering the scale 10 points, the teacher adds 10 points to each students' score?

Or does a curve require that a teacher give As to the highest 10%, Bs to the next 20%, and so on?

Just curious as to folks' opinions. I was speaking with a teacher who said they had applied a curve in the second example above - where they adjusted the 90-80-70-60% scale down 10 points. I said that wasn't what I considered applying a curve. But I have no knowledge of how that term is approrpaietly used in educational circles.
#2
Old 02-24-2009, 01:12 PM
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Originally Posted by Dinsdale View Post
In your opinion, what constitutes "grading on a curve"?

For example, if a teacher applies a scale where 90-100%=A, 80-89%=B, 70-79%=C, 60-69%=D, and 59 and below=F - did the teacher apply a curve?
No. And I won't hear anything from any of you heretics who think there are grading scales where 90% isn't an A. The 90-100 = A et cetera scale was written on the back of the Ten Commandments. Written under it is "Thou shalt never curve grades down".

Quote:
What if the teacher above finds his class did poorly, so he drops the standard for each grade 10 points such that 80-100%=A, 70-79=B, etc. - have they now curved the results?
Yes.

Quote:
How about, instead of lowering the scale 10 points, the teacher adds 10 points to each students' score?
I've never heard of a teacher doing that.

Quote:
Or does a curve require that a teacher give As to the highest 10%, Bs to the next 20%, and so on?
Something like this is usually what is intended when they drop the cutoff for an A. The teacher has an idea of roughly how many people in the class should be getting each grade, and adjusts the grade cutoffs to get approximately that result.
#3
Old 02-24-2009, 01:14 PM
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The sloppy way to do it is just to take the highest score and make that the new 100% for everyone. That isn't a real curve though. Truly grading on a curve means that that that the mean grade is a 'C' and there are as many 'F''s as 'A's no matter how well the class did overall. I had a few of those in college and they can be difficult and tend not to be very popular. That technique is sometimes used on psych tests to help illustrate a point. You actually had to break out a z-score calculator to figure out your real grade.
#4
Old 02-24-2009, 01:15 PM
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In my college courses, we were graded on a bell curve (which is what I think you mean by "curve"). So once all the tests were graded, the grades (A, B, C, etc) were relative to how the rest of the class did. I don't know the exact math (although I'm sure you could easily find something online) but the end result was that the kids with the highest scores relative to the rest of the class were the ones who gots A's. I think this fits best with your example that X percentile gets an A, the next highest percentile gets a B and so on. So even if I only got 60% of the answers correct, I might still have gotten an A because everyone else only got 40% of the answers correct.

In fact, this is basically what happened to me when I got my first college chemistry test back with a 63. I was all prepared to call my parents and tell them that I failed my first test but it turns out, that was a B. I love that bell curve!!
#5
Old 02-24-2009, 01:15 PM
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Technically, grading on a curve implies some sort of non-linear conversion of percentage correct to grades--though it doesn't have to be to a bell curve (your example). For example, some teachers use a "square root curve", where you take the square root of the percentage correct and times that times 10--under this curve, 50% correct becomes a 70 on a 1-100 scale (or a C on a letter scale, which are unusual in high schools these days) and 90% correct becomes a 95 on the same scale.

Colloquially, any shift in grades is called a curve.
#6
Old 02-24-2009, 01:20 PM
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To me it means that the number of students getting As, Bs, etc, is decided before grading starts. So the top X% gets an A, the next Y% gets a B, etc. You assign letter grades to match a certain distribution, not necessarily bell-curve but AIUI that's where the name comes from.

Just moving the cutoff % for an A up or down based on how hard the test is? I wouldn't quite call that a curve, since you're not necessarily competing against other students to get one of the limited number of A's and B's.
#7
Old 02-24-2009, 01:22 PM
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Quote:
Originally Posted by Dinsdale
Or does a curve require that a teacher give As to the highest 10%, Bs to the next 20%, and so on?
As I understand it, this is the "traditional" method of curving: mapping the scores to a literal bell curve and assiging the final grades based on the results. I have heard anecdotal accounts that there are still teachers who use this method, but I've never actually encountered one.

In my own experience, to a man (or woman), every teacher I've ever had who graded on a "curve" used the same method: subtract the highest score in the class from 100, add the difference to every student's score, and assign final grades based on that, just as Shagnasty describes. This held true in both junior high and high school (class of '02). To my knowledge, none of my college classes have been graded on a curve.

Last edited by Roland Orzabal; 02-24-2009 at 01:23 PM.
#8
Old 02-24-2009, 01:28 PM
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Originally Posted by lilflower View Post
In my college courses, we were graded on a bell curve (which is what I think you mean by "curve").
Throughout my entire schooling through law school I never encountered a true bell curve. My understanding is that a bell curve would require that as many students get Fs as get As, and the same number get Ds as Bs. I've never been in a class where as many folk got Ds and Fs as got As and Bs. Usually the curves would reflect something like top 20% get As, next 30% get Bs, everyone else gets Cs (except for a couple of folk who work really hard at earining a D or F).

Anne: The method where the teacher adds points to everyone's scores is common in my kids' high school. So my kid will get a 103%, even tho she got some questions wrong. For whatever reason the teacher wanted to stick with the 90/80/70 scale, so she added a certain number of points to everyone's scores to get a "more desireable" distribution of grades within that scale.

My question with that method was, souldn't the added points reflect the number of questions answered correctly? I'm no mathmetician, but it doesn't seem quite right to me thatboth the kid scoring 40 and the kid scoring 90 get the same number of points added to their score.
#9
Old 02-24-2009, 01:31 PM
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Manda and sugar - I think you hit the nail on the head as to the disjumct between me and the teacher. I was speaking as to the "techinical" definition of a curve, whereas she was using the far more common colloquial def.

Thanks mucho!
#10
Old 02-24-2009, 01:34 PM
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Originally Posted by Manda JO View Post
(or a C on a letter scale, which are unusual in high schools these days)
Letter scales are unusual in high school now? Really? Christ, I didn't graduate that long ago. And I'd never heard of any HS that didn't use letter grades when I was in HS.
#11
Old 02-24-2009, 01:37 PM
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Originally Posted by Rigamarole View Post
Letter scales are unusual in high school now? Really? Christ, I didn't graduate that long ago. And I'd never heard of any HS that didn't use letter grades when I was in HS.
I think it's C's that are unusual, not letter grades.
#12
Old 02-24-2009, 01:52 PM
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Originally Posted by Anne Neville View Post
I think it's C's that are unusual, not letter grades.
Letter grades on report cards are pretty unusual, in my experience: report cads say "89" or "94" or "72", not "A" or "B" or "C". There may be a district policy that 90-100 is an A or whatever for the purposes of GPA, but it's a 100 point scale. In cases like this, a teacher has to add points to a grade, not redefine the letters, because they don't turn in letters to be printed--they turn in a number between 1-100.
#13
Old 02-24-2009, 02:01 PM
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Originally Posted by Manda JO View Post
Letter grades on report cards are pretty unusual, in my experience: report cads say "89" or "94" or "72", not "A" or "B" or "C". There may be a district policy that 90-100 is an A or whatever for the purposes of GPA, but it's a 100 point scale. In cases like this, a teacher has to add points to a grade, not redefine the letters, because they don't turn in letters to be printed--they turn in a number between 1-100.
Huh, so things have changed since I was in high school. Our report cards always had letter grades, not numbers. No plus or minus grades, either.
#14
Old 02-24-2009, 02:50 PM
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Perhaps it's a regional thing.
#15
Old 02-24-2009, 03:24 PM
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Just for completeness.

A few of my CS professors would grade on a strict bell curve. They even took pride in displaying histograms to show how well the results of the tests they designed fit the perfect curve.

Last edited by UncleRojelio; 02-24-2009 at 03:27 PM.
#16
Old 02-24-2009, 03:30 PM
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In high school, and I think a few timeis during college, whenever the teacher would grade with a curve he'd get the highest grade, figure out how many points the student would need to bump that highest grade to 100% then give those points to everyone else.

So if the test had 100 one point questions and the highest grade was a 95, everyone else would get an additional 5 points.

Seem pretty stupid to me but I'd never tell a teacher that
#17
Old 02-24-2009, 03:38 PM
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Let's say I had a class of 25 students. I would mark the tests and then write the marks down on a piece of paper. Then I would look for natural groupings. If there were five students with marks around 70 and nothing higher, then they would get A. If there were four and one around 90, that was a problem and it would depend on whether I thought that one was unusual. And I would continue in that fashion. It was also possible that there be no A if I felt the class was unusually dense. Much the same at the bottom. Students way below the median would fail. If there was a large cluster at the bottom and no one way below, they would all get the same mark, but whether D or F would depend on whether I felt they deserved to pass in some platonic sense.

The province of Quebec used an interesting way to curve marks. They would average class marks with the provincial exam marks. But first they would adjust each class's class marks so that the the class marks had the same mean and the same standard deviation from what that class got on the provincial exam. And this adjusted average was the final mark. The effect was to take into account the class work in such a way that an unusually hard or easy teacher could not skew the results.
#18
Old 02-24-2009, 04:07 PM
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Originally Posted by UncleRojelio View Post
Just for completeness.

A few of my CS professors would grade on a strict bell curve. They even took pride in displaying histograms to show how well the results of the tests they designed fit the perfect curve.
I had a Statistics professor in school who got a double bell curve. He gave the students at the top of the curve all As (they'd scored 100), then the next curve got Cs, Ds and Fs. Each of his tests had ten questions and gave no partial credit.

He was an elitist jerk who didn't realize that a core group of students, almost all of whom were pre-Med, got a hold of his old tests and were cheating. He was possibly the worst teacher I had in college, taught the class by reading from the text and spent the rest of the time complaining that it wasn't fair that he wasn't teaching in Cambridge (Mass) and suggesting that anyone attending our school was an idiot.

I later taught myself a sufficient amount of statistics by reading someone else's book.
#19
Old 02-24-2009, 04:24 PM
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Originally Posted by Hari Seldon View Post
Let's say I had a class of 25 students. I would mark the tests and then write the marks down on a piece of paper. Then I would look for natural groupings. If there were five students with marks around 70 and nothing higher, then they would get A. If there were four and one around 90, that was a problem and it would depend on whether I thought that one was unusual. And I would continue in that fashion. It was also possible that there be no A if I felt the class was unusually dense. Much the same at the bottom. Students way below the median would fail. If there was a large cluster at the bottom and no one way below, they would all get the same mark, but whether D or F would depend on whether I felt they deserved to pass in some platonic sense.
This is what a number of my professors in college did. You can't really fit a bell curve to the kind of grade distributions you're going to get with 10 students in the class (which is not unusual for an upper-division course for physics majors), and the raw scores are likely to be low enough in those classes that some kind of curve is needed so that everybody doesn't flunk.
#20
Old 02-24-2009, 04:58 PM
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Originally Posted by Shagnasty View Post
just to take the highest score and make that the new 100% for everyone
I only had a few courses in my life that were graded on a curve and they were all done basically like this. Unlike others here, the only place I ever got graded on a curve was in college. Heck, it was usually the first question some kid would ask in each class, each semester: Do you grade on a curve? This technique can lead to some really interesting results and very unhappy classes, like when one person gets an A and the next highest grade is a D.
#21
Old 02-24-2009, 05:31 PM
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Grading on a curve means that you compute the mean and standard deviation of your grades, and assign the letter grade cutoffs so that a certain proportion of the results falls in each category. For instance, the top 10% might be an A, the next 20% a B, the middle 40% a C, the next 20% a D and the bottom 10% an F.

There are teachers who simply add the difference between 100 and the highest grade to each score and apply a scale based on that. They don't know what a curve is.
#22
Old 02-24-2009, 05:47 PM
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Originally Posted by Manda JO View Post
Letter grades on report cards are pretty unusual, in my experience: report cads say "89" or "94" or "72", not "A" or "B" or "C". There may be a district policy that 90-100 is an A or whatever for the purposes of GPA, but it's a 100 point scale. In cases like this, a teacher has to add points to a grade, not redefine the letters, because they don't turn in letters to be printed--they turn in a number between 1-100.
I think this must be a regional thing. I've never heard of any school or even college that puts anything but letters on a report card or transcript. This is annoying, since some of my teachers set their scales high, like 94-100% = A.

In my high school, every time I've had a test graded on a curve, it's been the simple "set the highest score to 100%" kind. The math teacher always talked about how he was going to grade it with a true bell curve, but he never actually followed through.
#23
Old 02-24-2009, 06:04 PM
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Originally Posted by lilflower View Post
In my college courses, we were graded on a bell curve (which is what I think you mean by "curve"). So once all the tests were graded, the grades (A, B, C, etc) were relative to how the rest of the class did.
I've had teachers like this in the past and I think that is a BULLSHIT way to grade. I really did have a teacher who made the cutoff for a B 90% because so many people did so well on the exam.

In my opinion how other people perform on their exams should have no bearing on your grade. Period.
#24
Old 02-24-2009, 06:04 PM
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The weirdest 'curve' I ever had was a linear progression where the highest grade got no increase but the lower grades were raised progressively so that the mean ended up where the professor wanted it.
#25
Old 02-24-2009, 06:20 PM
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I agree that a curve should mean distributing grades along a normal distribution, but in practice it means inflating the grades in some arbitrary way to protect the teacher at the expense of the student.

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Originally Posted by Dinsdale View Post
My question with that method was, souldn't the added points reflect the number of questions answered correctly? I'm no mathmetician, but it doesn't seem quite right to me thatboth the kid scoring 40 and the kid scoring 90 get the same number of points added to their score.
I think the intention is to remove the grr caused by poor question writing or bad teaching. If your top students didn't get #2, #7 and #21 right consistently across the board, then it was probably a matter of the teacher not teaching or not testing the material covered in #2,7 and 21 adequately. "Throwing those out" by giving everyone the points for them is a way to keep your students quiet and not penalize their grades for your inadequacy. And the laziest of the teachers, rather that noting if it's the same 3 (or 10) questions that every student is getting wrong and fixing their teaching, will just assume that and give the points without checking. Of course this means that if you got those particular questions right, you get double points for them and if you got them wrong, you don't, so you're still penalized in the larger picture. It's stupid.

Sorry, I'm kinda bitter about this practice. In my first biology class at college, the teacher was so terrible and the test scores so dismal as a result that he just kept "curving" the tests more and more. I mean, he had two choices: teach better, or make the tests easier. Otherwise he'd have a classroom full of students who didn't pass - which doesn't look good for his annual eval, does it? Rather than teach better, he tested easier, until eventually a Unit Exam would consist of 25 multiple choice questions, of which we had to do 15, and he'd still add 5 points to everyone's score at the end. I got an A in the course, of course, but didn't learn a damn thing, which is now hurting me in my higher level courses, lemme tell you. It was humiliating to get my first test back in A&P II and find the whole first page covered in red - review stuff which I was supposed to learn in BIO101 and didn't, despite my A.

I agree, Cubsfan, it's bullshit. It makes "90%" meaningless. 90% of what, exactly? 90% should mean that I've mastered and can demonstrate that mastery of 90% of the material covered in the class.
#26
Old 02-24-2009, 06:39 PM
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Originally Posted by WhyNot View Post
I agree that a curve should mean distributing grades along a normal distribution, but in practice it means inflating the grades in some arbitrary way to protect the teacher at the expense of the student.


I think the intention is to remove the grr caused by poor question writing or bad teaching. If your top students didn't get #2, #7 and #21 right consistently across the board, then it was probably a matter of the teacher not teaching or not testing the material covered in #2,7 and 21 adequately. "Throwing those out" by giving everyone the points for them is a way to keep your students quiet and not penalize their grades for your inadequacy. And the laziest of the teachers, rather that noting if it's the same 3 (or 10) questions that every student is getting wrong and fixing their teaching, will just assume that and give the points without checking. Of course this means that if you got those particular questions right, you get double points for them and if you got them wrong, you don't, so you're still penalized in the larger picture. It's stupid.
Or you think you've covered a subject adequately, find you haven't, and use that information to shape your lessons going forward. Assessment is a dynamic process, a communication between student and teacher--people don't even know if they understand something until they try to do it, and they won't try to do it until it counts for something. So you have to have assessments, and sometimes you find out that while everyone said they understood and seemed to be getting a concept, they really didn't.

Quote:
[Snip . . .]I agree, Cubsfan, it's bullshit. It makes "90%" meaningless. 90% of what, exactly? 90% should mean that I've mastered and can demonstrate that mastery of 90% of the material covered in the class.
I am going to disagree with you here. I think it's a weird idea that we define strong success in a course as mastering 90% or higher of the material offered, and that mastering 70% is barely adequate. 90% is inherently meaningless--it's just a number. Context defines it, and the context of each course is different. In my AP Econ class, I teach way above what I expect my kids to actually learn (and what they need to pass the test), because I expect them to forget or not really understand the upper level of what I am saying. I also teach above my expectations because it gives me something to say in between the endless repetitions of the "basic" stuff that I really need to say/demonstrate 8000 times for the very bottom of my class.

If I limit my teaching (and testing) to where anyone who masters 70% of it is "barely passing", I can't differentiate between the different needs of my student. In the context of my course (and this is mirrored on the AP exams), 50% mastery is on par with someone who has completed a college course in the subject. So it should be a C. And someone who has mastered 85% of the material should get an A. And someone who has mastered 95% (and I have about one a year), needs to know that they are the bomb and they didn't waste their time sitting in my class.
#27
Old 02-24-2009, 07:02 PM
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Originally Posted by Manda JO View Post
Or you think you've covered a subject adequately, find you haven't, and use that information to shape your lessons going forward. Assessment is a dynamic process, a communication between student and teacher--people don't even know if they understand something until they try to do it, and they won't try to do it until it counts for something. So you have to have assessments, and sometimes you find out that while everyone said they understood and seemed to be getting a concept, they really didn't.
Sure.

I don't understand the rest of your post, to be honest. It seems like you're arguing that the 90/80/70 grading scale isn't a good one, which I don't disagree with necessarily. I think it depends on the course, the level and the students.

To be honest, I never had a 90/80/70 scale until I got to college. My high school courses were either 94/86/78 or, for some particularly brutal ones, 97/92/86.

Teaching more than they need to know is great, and I love teachers who do that. In such a case, 90% should reflect mastery of 90% of the material they should know on exit, IMHO. Otherwise, what does it mean? 9/10's of what? 90 out of 100 whats?

If they can be expected to do okay in their next class only mastering 70% of the material they should know on exiting yours, then fine. If they can't be expected to do well in their next class with only 70%, then it should be an F - a failing grade, and they shouldn't be allowed to do the next course in the series.

If not a single student masters enough material to do well in the next course (or the career you're training them for), then that indicates a serious problem with the teacher or the test. Giving them all passing grades by these dubious "curving" methods doesn't solve the problem.
#28
Old 02-24-2009, 07:25 PM
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Originally Posted by WhyNot View Post
I agree, Cubsfan, it's bullshit. It makes "90%" meaningless. 90% of what, exactly? 90% should mean that I've mastered and can demonstrate that mastery of 90% of the material covered in the class.
What does it mean to have mastered 90% of the material? Does it mean that you've memorized and can regurgitate 90% of it? Or does it mean that you know the material well enough to be able to draw connections beyond what's been discussed in class and the readings? Under the first notion, an absolute 90% cutoff for an A is definitely the right thing to do. Under the second, it's a little less clear.
#29
Old 02-24-2009, 07:52 PM
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Originally Posted by WhyNot View Post
I agree that a curve should mean distributing grades along a normal distribution...
The problem that many learned folk seem to forget is that a classroom is most often not of a sufficient size to give a population size from which one can expect a normal distribution. Perhaps in a large enough class, or across enough sections you can do this. But I've seen educators and business people try to do this with populations of under 20 and as small as five.

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#30
Old 02-24-2009, 08:46 PM
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It's a curve if your grade is dependent upon the other students' test scores.

So, if before the test is given, the teacher says "80% is an A, 60% is a B, 40% is a C" it is not a curve. It may be creative grading standards, but it isn't a curve.* If the test is given and the papers are scored, and then the teacher does some math and ends up with 80% being an A, it is a curve.
#31
Old 02-24-2009, 09:11 PM
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Originally Posted by Manda J
I am going to disagree with you here. I think it's a weird idea that we define strong success in a course as mastering 90% or higher of the material offered, and that mastering 70% is barely adequate. 90% is inherently meaningless--it's just a number. Context defines it, and the context of each course is different.
Learning is not a competition. When the class starts the expectation and requirements to achieve high-grades should be clear and should not include competing with classmates. Save that shit for the workplace. That was the point of my post.

Using your logic there should be no grades at all, just pass or fail.

Last edited by Cubsfan; 02-24-2009 at 09:12 PM.
#32
Old 02-24-2009, 09:22 PM
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As a professor, grading is the hardest part of the job.

When, say, test results come back, you want to be somewhat flexible (because you might have written a bad test, or had a bad day teaching, etc), but you also can't be too flexible (because you need to genuinely reward the superior students).

It's not easy.

But the bell-curve doesn't make any sense, nor does an inflexible 90-80-70 thing.
#33
Old 02-24-2009, 10:23 PM
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Originally Posted by WhyNot View Post
Sure.

I don't understand the rest of your post, to be honest. It seems like you're arguing that the 90/80/70 grading scale isn't a good one, which I don't disagree with necessarily. I think it depends on the course, the level and the students.

To be honest, I never had a 90/80/70 scale until I got to college. My high school courses were either 94/86/78 or, for some particularly brutal ones, 97/92/86.

Teaching more than they need to know is great, and I love teachers who do that. In such a case, 90% should reflect mastery of 90% of the material they should know on exit, IMHO. Otherwise, what does it mean? 9/10's of what? 90 out of 100 whats?

If they can be expected to do okay in their next class only mastering 70% of the material they should know on exiting yours, then fine. If they can't be expected to do well in their next class with only 70%, then it should be an F - a failing grade, and they shouldn't be allowed to do the next course in the series.

If not a single student masters enough material to do well in the next course (or the career you're training them for), then that indicates a serious problem with the teacher or the test. Giving them all passing grades by these dubious "curving" methods doesn't solve the problem.
I think we largely agree here. What I am saying is that if mastering 75% of the material will make you super-prepared for the next class (and on most AP exams, 75% of possible points is a 5, the highest score), then it's ok if 75% mastery = the highest possible grade. A system like that doesn't mean that the teacher is a bad teacher, as long as they have reasonable expectations. As many grade systems demand a numerical entry where an A = >90%, teachers have to curve the percentage grades to fit that set scale.

I can use half a test to find out whose managed to master the basic information of the class. The other half is a tool for learning--both an incentive for the top kids to really pay attention and keep trying, because they will get a chance later to show their chops, and as a learning tool--many people won't really try to work their way through something, push through regurgitation and begin synthesis, until they really have to--until they are tested. So by putting a few problems on my test that really push them to apply what they have learned in new ways, they don't just show me what they've learned in the past, they actually learn new things.

Furthermore, having a wider range of what counts as success--a 50% spread instead of a 30% spread--it's easier to write a test that discriminates between "barely got it" "Kinda got it" "comfortable" "thoroughly understands" and "could teach the class". Something like a square root curve allows you to do this.

I don't doubt that there are teachers that use curves to cover up laziness. But curves can be useful teaching tools.
#34
Old 02-24-2009, 10:27 PM
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Holy christ...Jindal is the worst. Wow...he sounds like he's reading a script to a class of 3 year olds. Or maybe an infomercial.

Just terrible. How the hell did the pubs choose him to deliver this speech? Ugh..
#35
Old 02-24-2009, 10:27 PM
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Quote:
Originally Posted by Cubsfan View Post
Learning is not a competition. When the class starts the expectation and requirements to achieve high-grades should be clear and should not include competing with classmates. Save that shit for the workplace. That was the point of my post.

Using your logic there should be no grades at all, just pass or fail.

What does that mean? I never suggested competing with classmates, and I never advocated a bell-curve. There are many kinds of curves. I said that it's okay to teach a class in such a way where if you get 50% of the material you've covered the bare basics and deserve a C, and where if you've mastered 75% of the material you deserve an A. I very much think their should be grades, I just don't think they should always be 90% mastery = A, 69% mastery = no credit.
#36
Old 02-24-2009, 10:46 PM
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Quote:
Originally Posted by ultrafilter View Post
What does it mean to have mastered 90% of the material? Does it mean that you've memorized and can regurgitate 90% of it? Or does it mean that you know the material well enough to be able to draw connections beyond what's been discussed in class and the readings? Under the first notion, an absolute 90% cutoff for an A is definitely the right thing to do. Under the second, it's a little less clear.
Well, that leads us down the path of discussing authentic assessment, which is probably beyond the scope of this thread. (But I'd love you join you in a new thread about it, as I'm really excited by one of the best assessors I've ever had a class with right now!) For this thread, I'll just accept that "mastery" is whatever the teacher says it is.
#37
Old 02-25-2009, 12:03 AM
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Originally Posted by Silophant View Post
I think this must be a regional thing. I've never heard of any school or even college that puts anything but letters on a report card or transcript. This is annoying, since some of my teachers set their scales high, like 94-100% = A.
Where are you from? In high school and college, we were give number grades on our report cards. However, on our high school report cards there was a scale at the bottom that told you what the range was for As-Ds, so you could glance down and see that your 98 in History was an A+ and your 67 in Math was a D-. Every teacher and professor was held to the same scale (all As are from _ to _ points) for grades, though.

That I know of, I never had a teacher or professor who graded on a curve.
#38
Old 02-25-2009, 12:29 AM
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I'm in Minnesota, and my high school, the University of Minnesota, Southwest State University, and Minnesota State University just use straight letters. The teachers in high school all give us grade printouts so we can see the percentages, but on the report card, it's just the letters. This means, that, for GPA purposes, the 105% in Biology is worth just as much as the 91% in English (that teacher uses a 90-100% = A system), but the 91% in English is worth more than the 93% in Civics, whose teacher uses a 94-100% = A system.

And that's not even getting into the shitstorm that flies up twice a year, every year, when the college level course that isn't structured by quarters has to turn in a quarter grade and all the students in it go on probation because they're failing a class.
#39
Old 02-25-2009, 12:44 AM
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If anyone's keeping track, I've been in and had a kid in schools in the Chicagoland area for 30 years, and some sort of summary grade - usually A, B, C etc., but in his elementary school 4,3,2 and 1* - have always been used on the grade reports. Percentage grades were available upon request, but they aren't the official grades.

As a parent, I'd actually prefer percentages along with an interpretive score, to know if my kid was getting a skin-of-your-teeth C, a solid C or a little-less-television-time-could-make-this-a-B C.



*From an old report card:
4 - Exceeds Grade Level Standards
3 - Meets Grade Level Standards
2- Making Satisfactory Progress Towards Meeting Grade Level Standards
1 - Not Making Satisfactory Progress Towards Meeting Grade Level Standards

Last edited by WhyNot; 02-25-2009 at 12:48 AM.
#40
Old 02-25-2009, 12:58 AM
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As with many of life’s most difficult questions, Wikipedia has a page…

http://en.wikipedia.org/wiki/Bell_curve_grading
#41
Old 02-25-2009, 02:04 AM
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Quote:
Originally Posted by Silophant View Post
I think this must be a regional thing. I've never heard of any school or even college that puts anything but letters on a report card or transcript. This is annoying, since some of my teachers set their scales high, like 94-100% = A.

In my high school, every time I've had a test graded on a curve, it's been the simple "set the highest score to 100%" kind. The math teacher always talked about how he was going to grade it with a true bell curve, but he never actually followed through.
In New York City in the '60s all grades were numbers. The lower grades were by 5s, then there was an 88, and above 90 the increment was 1. MIT had a 5 as A, other places I've been had 4s. I don't think I've ever been anywhere that used letters.
#42
Old 02-25-2009, 02:12 AM
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I believe every class I ever took at MIT graded on a curve - I don't remember any of this preordained number stuff. Some professors gave really hard tests. After the test, the class average was announced, and grades depended on where you stood relative to that.

At Illinois I TAed for a very large second CS class, that was used to filter out the kids who had it from those who didn't. We got a lot of drops. We graded on a curve but a censored one, since most kids who were going to occupy the bottom part of it were gone. (Some didn't get the message.) We summed up the grades at the end of the term, and looked for natural breakpoints to assign the grades. We usually saw clusters, not nice bell curves.

When I moved down south, I taught for one term. In this school, pretty much everyone used the 90% = A formula. I didn't, because, to put it nicely, the students weren't quite the level I had experience with, and I didn't like giving tests that were all multiple choice. I discovered the absolute system when I gave my first test, and everyone freaked out about getting grades that would be Ds in most classes. They were very relieved about a curve there.

But this term did convince me to go into industry.
#43
Old 02-25-2009, 09:38 AM
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Technically, you normalize the data, and the median score is a C. Then your students kill you for giving out so many Ds.

In common usage a curve is anytime the scores are adjusted based on the performance of the class. Making the top score 100 is one way to do it. Looking at groupings is another. (I had one prof who would tell you to keep tallying up your scores, after each test he'd write everyone's cumulative point totals on the board (without names, of course) and say "if I were grading today, these would be As, these Bs....."). Giving X # of As is yet another (I had a great 'Science for English majors' type of course - 25% of the class got As, 50% Bs, 25% Cs - you could only fail the course if your test results were worse than guessing - but he'd let you retake the test - they were multiple choice 4 answer tests, you had to get 30% to pass - with a C)

I had one prof who used a 90/80/70 scale - but threw out test questions that had a high rate of people getting them wrong. He figured if half the class missed the question, it was a bad question or he did a bad job of covering the material.

I think the best system depends on the material - and the experience of the instructor.
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#44
Old 02-25-2009, 11:41 AM
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Quote:
Originally Posted by Cubsfan View Post
I've had teachers like this in the past and I think that is a BULLSHIT way to grade. I really did have a teacher who made the cutoff for a B 90% because so many people did so well on the exam.
I agree. If everyone in the class really really knows their stuff—which ought to be the teacher's goal, though whether it's realizable will depend on the ability and motivation of the students—then everyone should get A's. If everyone in the class is a moronic slacker who refuses to do or learn much of anything, the whole class should get F's.

The argument for grading on a curve is that it is a way of making up for tests/standards that are too hard or too easy (or perhaps poorly designed). A student's raw score is going to depend, not only on how much that student knows, but also how easy the test was. The solution to this, of course, is to give well-designed, well-calibrated tests and other means of evaluation.
#45
Old 02-25-2009, 02:40 PM
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Quote:
Originally Posted by WhyNot View Post
If anyone's keeping track, I've been in and had a kid in schools in the Chicagoland area for 30 years, and some sort of summary grade - usually A, B, C etc., but in his elementary school 4,3,2 and 1* - have always been used on the grade reports.
When I was in grade school in the CPS in the 60s-70s, grades on report cards were:
E-excellent
G-good
F-fair
U-unsatisfactory.

Letter grades were qualified with "effort" ratings of 1, 2, 3, meaning something like:
1-excellent effort
2-could try harder
3-unsatisfactory effort.

I always used to get a kick out of E2 grades - excellent work, but could do better!

Recently got a midterm "progress report" for my HS senior in the western burbs. They gave both a letter and a number grade - such as B-85.

I asked my kid about the "adding points" system, which she said is the only one her teachers have ever used if a class scores below the 90/80/70/60 scale. Says they take the median score, subtract it from 75, and add that many points to everyone's grade. Seems weird to me - a slavish loyalty to the 90/80/70/60 scale, but that's what she says they do. When questioned further she said she remembered "one or two" occasions where they added a number equal to the difference between 100 and the highest grade.

Another data point - in this HS they used to use a 94/87/78 scale for honors classes, but just this year or the last they went to 90/80/70 for all classes. Not sure why.

The only grading situation I remember clearly was in college, into to accounting. An A required 94. I had a 93.6. The SOB gave me a B, applying a "Nellie Fox" rule - no rounding up allowed.

I showed THEM! Next semester in the 2d accounting class, I got a solid C! The next semester I transferred the hell out of business!
#46
Old 02-25-2009, 10:27 PM
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Quote:
Originally Posted by ultrafilter View Post
Grading on a curve means that you compute the mean and standard deviation of your grades, and assign the letter grade cutoffs so that a certain proportion of the results falls in each category. For instance, the top 10% might be an A, the next 20% a B, the middle 40% a C, the next 20% a D and the bottom 10% an F.

There are teachers who simply add the difference between 100 and the highest grade to each score and apply a scale based on that. They don't know what a curve is.
That is what a curve is, technically. That said, I've never met a teacher, in high school or college, who used a normal distribution curve to determine grades. The term "curve" has evolved to colloquially mean any sort of method used to adjust grades. I've had teachers use the method where the highest score gets 100, the rest of the students get bumped up by the difference between the highest score and 100. I've had other teachers use some mysterious method in which "curve busters" could score well above 100. (I had one series of biology tests in high school where I scored in the 60s [a solid F] on one test, and then in the 120s the next three tests.) Then there were professors (in college mostly) who would look for clumpings in the grading, and then announce in class what the cutoffs for each letter grade was (one chem class I remember a 40% being a B). But they didn't have a blanket "add x amount of points" to your score policy. That one most closely resembled a classical curve, but the distribution was more like 20% A, 40% B, 30% C, 5% D, 5% F. I assume this was based on how the scores clumped.
#47
Old 02-25-2009, 10:37 PM
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I should add, we always had letter grades from grammar school to college (1980-1998). Well, actually, from kindergarten through second grade we only had three grades: + (excels), O (satisfactory), and *checkmark* (needs improvement.) Until college, 93-100 was an A, 84-92 B, 75-83 C, 70-74 D, 0-69 F (or "U," unsatisfactory, in grammar school.) In college, grades were much more fluid, but if teachers had numerical scales, they would generally be graded in 10s (90-100 A, 80-89 B, etc.)
#48
Old 02-25-2009, 11:25 PM
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Originally Posted by Dinsdale View Post
But I have no knowledge of how that term is approrpaietly used in educational circles.
I think the phrase is nigh meaningless. I hate when students ask if I will use a curve, because I always ask what they mean by "curve" and they never seem to know.

Quote:
Originally Posted by Hari Seldon View Post
Let's say I had a class of 25 students. I would mark the tests and then write the marks down on a piece of paper. Then I would look for natural groupings. If there were five students with marks around 70 and nothing higher, then they would get A. If there were four and one around 90, that was a problem and it would depend on whether I thought that one was unusual. And I would continue in that fashion. It was also possible that there be no A if I felt the class was unusually dense. Much the same at the bottom. Students way below the median would fail. If there was a large cluster at the bottom and no one way below, they would all get the same mark, but whether D or F would depend on whether I felt they deserved to pass in some platonic sense.
This is the only reasonable way to grade.

Quote:
Originally Posted by Cubsfan View Post
I've had teachers like this in the past and I think that is a BULLSHIT way to grade. I really did have a teacher who made the cutoff for a B 90% because so many people did so well on the exam.

In my opinion how other people perform on their exams should have no bearing on your grade. Period.
This only works if the tests are standardized. Otherwise, each test will be difficult in different ways, and the best way to figure out if I made a test too hard or too easy is to look at how my students did on it. Also, grading is always a judgment call. For example, I am now teaching an upper-level Maths course with 12 people. Some don't do any homework. They will fail. Others sort of understand the material. Some understand some of the material pretty well, but fuck up some of the other shit. And some understand most of it. Who gets what grade? 12 is too small to look at any kind of average, of course. I also know that the bar is set a bit lower for a course this hard. Understanding half of the important concepts is probably worth a B-? (Maybe a B?) How does one quantify "understanding half of the important concepts?" It's not as easy as you think.

I have no idea how Humanities profs do it. At least I have numbers that I can pretend mean things.

+1 to Manda JO. Especially about the "dynamic assessment" bit. Consider even that I will base the content of the second exam in some part on how he students did on the first! Also to the bit about 90% being meaningless. If I make my tests hard, then maybe an A student should get 65% or so. If I make them easy then maybe an A student should get 95%. Also, I don't neccesarily grade exactly the same each time. Way too many variables.
#49
Old 02-25-2009, 11:41 PM
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I think a curve is anything that deliberately alters student's grades based on total class performance or the "accepted norms" of the system (usually 90-100 A 80-89 B etc), for worse or better. And I've heard some horror stories about curves, the worst type are what I think amounts to a bell curve, Engineering classes are the most notorious here. My friend did tell me about the Curve From Hell™ in her 7th grade math though, everybody scored over 95%s consistently, the only people who ever got A's were the ones who got 100%s or 99.5%s, a "D" on a particular test was often around a 97-95 depending on the difficulty of the material. I heard about one quiz where everyone got 100% so EVERYONE got a "C", meaning 32 students pretty much got 30% arbitrarily shaved off their score.

But sometimes curves are just a way of acknowledging you may have written a bad test, or that maybe something was taught badly. I have seen 10 points added to everyone's score, I actually got extra credit on a humanities test because I very nearly 100%d it (about 2 points off) but most people failed or got close (fault of the kids, not the teacher in this case I can assure you, but the general gist was she thought it was partially her fault and didn't want to trash any GPAs).

I think the most non-evil use of curves is probably weighting by the relative importance of the material, I've rarely seen this done, but I've known (but never had classes with) teachers that would widen the allowed area for point for an A (meaning in the gradebook it would get converted to somewhere in the 90s) for particularly regurgitative things they admit they themselves usually look up (like Trig Identities was a big one, "you should know a few basic ones, but even when I'm doing stuff if the odd chance comes around that I need it for a paper I'll look it up"), or on occasion tighten the ranges for really, really important concepts to the material.

Last edited by Jragon; 02-25-2009 at 11:41 PM.
#50
Old 02-26-2009, 01:30 AM
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For example, if a teacher applies a scale where 90-100%=A, 80-89%=B, 70-79%=C, 60-69%=D, and 59 and below=F - did the teacher apply a curve?

That's generally the definition of NOT grading on a curve. Any other method that somehow moves the average grade (whatever that is) towards the mean or median score is a form of grading on a curve. AFAIK there is no uniform way in which this "curving" process is done. For instance, the average grade may not be considered a C and there are not necessarily hard cut-offs for the various grades. It's because of this arbitrariness in grading on a curve that some instructors just use the 90-100=A, 80-89=B, etc. approach for grading in order to avoid grade disputes.
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