Do you really want that grade "curved"? (2024)

Whatdoes it mean to curve grades?

Students generally assume that curving means an upward adjustmentof low test scores, but the basis of the practice derives fromassumptions about statistical distributions of scores (bell curve).If you assume that scores should fit a normal curve, then itmakes sense to "normalize" them so they fit under a normal curve.Normalization also requires that overly high scores be adjusteddownward for conformity. Either way, data are distorted and someinformation is lost. Look at some data, then consider all theimplications of "grading on a curve".

A sample can provide perspective for students who are trying tounderstand the vagaries of performance and rewards. The followinggraphics summarize data from 422 students who finished the course,Biol 222 Vertebrate Organization over a 15-year period.These are self-selected students in a course at a selectivecollege; they do not represent a general population. Also, students,courses, exams, even the teaching of one professor vary with eachyear.

The line shows the infamous normal distribution, the "bell" curve.This sample is large enough to describe a fairly even curve. Theaverage is 65. Absence of individual averages in the 90's suggeststhat I am indeed a hard grader (or that I am living up to my goal ofchallenging students). Notice that the distribution of students isskewed toward the higher end of the curve, but then Hamilton studentsare intelligent, and they are good workers. Professional educatorssuggest that results should fit "the curve", and in this case thatwould mean curving grades down. Most students wouldprobably not welcome that practice.

Compare the chart of grades below to the chart of cumulativescores above. What do you see?

I resist distorting class perceptions by "curving" each test scoreduring the term, but the final assignment of grades suggests they areeffectively "curved". There are no averages at 98%, but a fewstudents received A+. A few students failed. If a student fails tocomplete the work there is little choice in evaluation of that work.Fortunately, most Hamilton students are good workers who use theirintelligence. I try to recognize student improvement and anindividual's rise to a challenge when I assign final grades.

What does a percentage mean?

A percentage shows how much of a particular exam was dealt withsuccessfully, but what test is so perfect that it could completelydetermine extent of knowledge or ability? If a student gets a gradeof 90%, it does not mean they know 90% of everything in the subject.Wise students will begin to look at scores as a place on a continuumof achievement rather than analysis carved in stone.

Averages in my classes may be in the 60% range. Nineties are rare.I am not alarmed by apparently low numbers, but these scores do tendto worry conscientious students who are conditioned to think in termsof 90% = A, 80% = B, etc. This can undermine class morale, and lowclass morale can undermine student ability. That does concernme, so I offer some suggestions for dealing with these anxieties.

How to deal with the anxiety

Do not expect to be graded solely in comparison to yourclassmates, but you can use the class data to infer your generalstanding in terms of what your class is doing. Where are you relativeto the class mean? For example, if you have a 72% average, but theclass average is 52%, you are doing better than your score mightsuggest to you. Adding 20 to each number would make the class averagea traditional 72% and give you a very respectable 92%. This is a formof "curving" you can do for yourself with each examination. Simplylook at the class mean (which is always presented) and adjust it tofall into the 70% range then apply the same correction factor to yourscore or cumulative average. You can do this in any of your classesif basic information is provided, but there is a limit to thisapproach.

Expecting to be graded solely in comparison to your currentclassmates is simplistic, even naive. Thoughtful professors use theperspective of years of experience to consider what students can do.Do not assume, that every class will have a certain percentage of A'sor F's. You might be a strong person in a relatively weak group, oryou might find yourself in fast company. The situation of each classbecomes apparent as the semester progresses. Sometimes there are no Astudents -- often there are no failures. This is also a real-lifeview of how work is evaluated that is not unique to professors andexams.

Does a professor give grades, or assignthem?

Grades should mean something more than flattery. Grades speak tothe world, not just to classmates, parents or a campus. Eventuallyperformance shows and counts, and must be competitive on the merits.I encourage students to sharpen skills now by selectingchallenge. You, and your family, are paying a lot for a realeducation. When you evaluate courses (or colleges) consider thatthoughtful professors do not give grades, they assignthem on the basis of the evidence provided by a student'swork.

Grade inflation

Grade inflation is not as flattering as most students would liketo believe. Grade inflation lowers standards, discounts achievementand hurts students in the outside world more than students realize.The grades in my example, like the grades of most colleges, areskewed toward the higher end of the curve. Average is a definitionfor C, but college averages based on grades assigned are no longer C.In 1990 averages were more often B, and they were moving toward A- in2005. Reports from shared institutional research in 2015 gave an average grade of A at many prestigious colleges. If 80% or 90% of students receive a grade of A, or graduatecum laude (as reported at some Ivy League schools), what doesthat tell you about challenge and standards? How much did thosestudents grow during their college years? Did those students obtainan education, or just a credential? Consider how much an inflatedcredential is worth when future evaluators do not see the abilitythat inflated grades led them to expect. Grade inflation does nofavors for either students or our society.

There is evidence that students are not alwaysdeceived. Students with standards and the willingness to apply effortfor real achievement resent a pass-fail system that assigns them thesame final evaluation (pass) as students who give considerably lesseffort and produce a lower quality result. Letters of recommendation,if they are read, might offer insight that numerical evaluations nolonger provide, but in a society where test scores seem to be thedominant currency, we need to consider what numbers really mean.

Some data that are available on the web have beengleaned and compared in some nice graphics at gradeinflation.com.The author of that website published related thoughts in theCSMonitor 2009 as "Gradeinflation gone wild".

What do educators think they are doing?

Supportive arguments for the practice of grade inflation often cite a student's acceptance at a selective school, requiredeffort, or concernabout harming students with lower grades. If these are now thecriteria for grading, then the professoriate is abdicating animportant responsibility. Students presumably chose education forhelp in improving themselves. On what long-term basis canstudent-customers identify real standards? Do students bear anyresponsibility for the consequences of minimal efforts? Do facultyreally intend to stop evaluation at an admissions office, and beforestudents enter a class? Is there no harm done to graduates who do notsucceed because they were not taken seriously or because they did notrealize that they were seen as unprofessional? Perhaps we need to beasking just what it is that we expect education to be doing beyondentertaining young people and keeping great numbers of them away fromemployment for several additional years.

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Footnote: This is an expanded and periodically updated version of what I originally wrote in 1990 to help my students understand some of the thought that can go into grading. Once I posted this on the web, appreciative e-notes arrived periodically from other teachers all over the county. It is good that this helps support other teachers in their desire to encourage quality. Unless evaluators consider the implications of their actions, and those being evaluated understand the long-term implications of having no standards, the general quality of work in our society will continue to reflect declining standards.