The Merits and Demerits of Grading on a Bell Curve

This entry will touch upon the good, the bad, and the ugly aspects of grading on the infamous ‘Bell Curve‘.  For those of you unfamiliar with either this grading practice, or normal distributions in general, let me briefly elaborate:

Now, for the sake of brevity, I will try to spare you from all of the mathematical gobbledygook and statistical mumbo-jumbo that traditionally comes with these sorts of explanations.

1.  What exactly is a bell curve?

A bell curve, or more specifically, a Gaussian Distribution, is a symmetric curve that is pronounced in the middle, and tapered off at the edges (it really does look like a bell).  As such, the middle portion under the curve contains more area than either of the ends.

 

This is what a typical bell curve looks like.

 

2.  What does “grading on a curve” mean?

When courses are said to be “marked on the curve,” this usually means that a predetermined percentage of students will obtain each grade.  For example, a certain amount of students will receive an A+ (top 4%), a certain amount will receive an A (next 7%), and so on and so forth.  Ultimately, the distribution of grades will fit ‘nicely’ on a bell shaped curve; with the majority of students obtaining marks near the middle portion of the curve (‘B’ range).  Unfortunately, however; this also necessitates the fact that a certain percentage of students will inevitably obtain ‘F’ grades, and fail the course entirely (bottom 6%).

Attitude versus Aptitude – A Rubber Band Analogy

Oftentimes, we are unaware of our inherent limitations, whether they be intellectual, physical, spiritual, etc.  I’m willing to take this a step further, and posit that most of us tend to underestimate, and consequently, never fully realize our true potentials.  Today’s (opinionated) entry will revolve around the highly contested, “Nature versus Nurture” debate; something that never seems to fail at creating a considerable degree of ruckus amongst academia and laymen alike.  However, instead of the politically correct terms, ‘nurture’ and ‘nature,’ I prefer to use the words ‘attitude’ and ‘aptitude.’ (Why?  Oh, no particular reason, but in my mind, “nurture” seems to imply that we have less control over the matter than we actually do)

 

Bands come in every shape and size ... How we make use of the ones that we've been given, is what really counts.

 

Although the following analogy can generalize to a myriad of situations, let’s use academic performance as an example.  First of all, I want you to imagine a rubber band (any color will do).  Let us associate this band with a person; Person A.  Now imagine a second, larger band, and associate that with Person B.  You’ve probably realized by now where I’m headed with this, that is to say, one’s intrinsic ‘aptitude’ can be modeled by the size of one’s (metaphorical) rubber band.  Thus, the greater the magnitude of one’s (unstretched) rubber band, the greater the magnitude of one’s inherent abilities.  By the same token, we can also attribute one’s ‘attitude’ with the degree to which one is willing to stretch his or her band.