Grading on a Curve Pros and Cons

This article comes from an author who has never been an outstanding achiever as far as grading is concerned. I have always blamed my dismal performance on the grading system and tried to find out its flaws. Well, a healthy alternative to a normal grading system is grading on a curve. So, let us explore its pros and cons.

The Concept

The entire idea behind this kind of grading system is to boost the performance of the lagging students in a class. The advantage of those students who have worked hard for good grades should also be there. Now, how will you do that? The answer to this question is a very novel idea in grading on a curve system. It is a method of assigning grades, in which a predetermined frequency distribution on a grading scale are yielded. Simply put, the disadvantage of the disadvantaged is reduced while hard workers get their due.

The grading proceeds in three different steps.

Step #1: The numerical scores of the tests are obtained. If the order of these scores represent the skill of the student, then the actual numerical score is unimportant.
Step #2: These numerical scores are converted into percentile scores relative to highest scorer.
Step #3: The percentile scores are then converted into grades.

As simple as these three steps may sound, there is a twist to this. When the teachers are converting percentiles into grades, they do so according on a 'percentile scale'. The width on this scale indicates the desired relative frequency distribution of the grades. This concept can be understood better with an example.

Consider that students in a class are graded into three categories, say X,Y & Z. The top achievers of the class have to be an exclusive group. So reserve X to the top 10% achievers. Let the next 20% be given Y, and the rest be in Z. The frequency distribution of the number of students in all three categories can be determined or tuned in advance.

Pros and Cons

The Benefits

• Relative Performance: The grades are assigned according to the relative performance of other students, so the difficulty of the subject itself is masked. This gives a sense of confidence to the student to tackle any subject.
• Difficulty in Comparison: The percentile scores are calculated according to highest score achieved in the class. This may not be very high. So the comparison with the numerically high scorers of other systems becomes impossible. In my opinion, this is leveling the playing field for every student.
• Easier to Go to College: More often than not, the relative score is generally higher than the actual numerical score. This way it becomes easy to get into college.

The Drawbacks

• Grade Margins: Grading on a curve increases the problem of those students who are near to the margin between the two grades. It may happen that a student is getting grade B in the normal grading system, but is getting grade C in the curve grading system. This is a big problem.
• Study Groups: Better performance by the study groups may show that the curve grading (the actual curve) is peaking, but individually, this may not be the case. The student may end up performing below par.
• Dealing with Different Grading System: A student who is habituated with grading on a curve system in schools, is in for a rude shock when he encounters a different system (this may happen when he enters the college or a graduate school). Typically low performing students who are used to getting better grades may not adjust to the new system quickly.

The pros and cons of this system are many. But it is definitely helpful for the weaker students, and at the same time, acknowledging the strengths of achieving and hard-working student. This should be the only reason to adopt this system.