Did You Make The Sigma?

By Jonathan H. Esensten

It’s a question whispered in the basement of the Cabot Science Library, by a select few students, usually only among the best of friends. How did it go? Did you make the sigma?

Most undergraduates go about their entire careers here without thinking much about the sigma. It’s one of those things—like the Porc or the Pudding—that affects only the elite among us. It’s a different kind of elite, however, who are concerned with the sigma.

How so? The letter sigma is the mathematical symbol for the underlying population standard deviation, which marks off important divisions of the Gaussian distribution. That distribution is better know as the bell shaped curve, and it has been used to rank you against your peers since you first learned to bubble in letters in fourth grade. Its single broad hump and leisurely asymptotic decline account for the gifted, the dull and the discontented masses in between.

But as we all know, grade inflation at Harvard has made distinguishing among good students nearly impossible, especially in the humanities. Papers and tests get letters grades, from which a standard deviation cannot easily be computed. Even if one were to use Harvard’s 15-point grading scale to calculate the standard deviation for an exam in an English class, the value would likely hover around one—far too small to make meaningful comparisons. It has become all too common for the goof-off and the hard-working genius to be separated by a single plus or minus on their transcript. When almost half of grades given out at the College are A or A-minus, distinguishing oneself in the classroom is not a matter of being better than everyone else, but of being perfect.

Therefore, the only reasonable way to separate oneself from the rabble, given that a B means a student showed up for class most days, is to get straight As. In the humanities, such a feat entails making friends with the TF, going to the professor’s office hours and doing all the reading. It’s not pleasant, but the path is clear and there are many factors that contribute to the final grade. In science classes, which give numbers for grades on the midterms and finals, the only way to ensure that A is to collect the requisite number of points. Of course, no one knows that number until the course is finished.

Thus, the standard deviation (“sigma” should not be used in this context for what is really a sample standard deviation but, alas, that is the slang) has become a fetish among certain circles of science concentrators because it’s generally agreed that “making it” on an exam—that is, getting one standard deviation or more above the average—is a guaranteed “A.” Assuming that scores on an exam are normally distributed, making the “sigma” means doing better than roughly 85 percent of the class. Students who miss the average by a sigma also know that 85 percent of the class did better than they did. If the scores on a test are clustered together near the mean, the sigma can be small. Missing one question on a large exam can be the difference between getting the sigma or missing the mean. Some students take especial pleasure in getting not one, but two standard deviations above the average. Such an accomplishment is often whispered about among the cognoscenti for weeks, partly out of fear, amazement and the comforting knowledge that their one sigma is just as good as his two.

Some people will squawk out the bromide that we are here to learn and not to compete, that the pleasure derived from a course should not be proportional to the grade we receive. The problem with this claim is that it’s really not true. We are here to learn, but we are also here to distinguish ourselves. In an academic community, distinguishing ourselves means pushing forward our accumulated knowledge of the world, working to improve our collective understanding, not just ourselves. Harvard is no longer a gentleman’s finishing school, but a serious place of intellectual inquiry, which can give the resources to push knowledge forward only to those who merit such resources. University President Lawrence H. Summers spoke in October about making the academic experience the center of College life. He has since expressed his intention to tackle grade inflation. Those two issues are intimately linked.

Summers has the right idea because getting rid of grade inflation is the only way to kill the cult of the “sigma” and refocus students from being perfect to actually learning. When the only acceptable grades in popular science courses are A and A-minus, top students are forced to compete brutally for those scores. If the B were restored to its position as an honorable grade, it would take much of the pressure off of those students to “be perfect,” as they have been for their entire careers so far. If students knew they could not be “perfect,” they would be more likely to study for the knowledge than for the grade. They would try to learn to think, rather than to learn to take tests. Some of us might even take an afternoon off now and then.

An average grade in popular science courses should be a B-minus. One standard deviation above the average should earn a student a B-plus. Only those truly exceptional students—those rare double-“sigmas”—should be awarded an A-minus. Put the A out of reach, and most of the sigma fiends will mellow out. Harvard students have spent their whole lives being perfect. If there is anything this school should teach them, it’s that they are not.

Jonathan H. Esensten ’04, a Crimson editor, is a biochemical sciences concentrator in Lowell House.