Forced grade distributions

Wharton management prof Adam Grant argues in a recent NYT op-ed that colleges should not use forced distributions when handing out grades.  In a forced distributions, there are limits on the number of students who can receive a particular grade, e.g., only 25% can get A's, the next 35% can get B's.  This type of system is in place in core classes at many of the world's leading business schools.

Grant sees two serious defects: one related to fairness and the other related to collegiality.  The forced curve might say there can only be ten A's in a class, but what if 15 students have performed at A level?  What if only five students perform at A level, do the other five get an A anyway?  Experienced professors who have taught the same course year after year are in a very good position to make sure grades are equitable relative to standards, Grant argues.  As for collegiality, forced distributions turn classmates into adversaries in what Grant calls a "zero-sum game."

Forced distributions do prevent grade inflation.  Today over 40 percent of all grades are in the A range.  Grant in essence is arguing whether the cure is a larger danger than the disease.

Closing note:  there are no forced grade distributions in the NC State MBA program.

Grade inflation

NYT blog by Catherine Rampell shows how dramatically grade distributions have changed at over 200 colleges and universities.  In 1960, 15% of all grades were A's, which rose to 31% by 1988 and 43% by 2008.  B's held their own, but the odds of getting a C have plummeted, dropping from 35% to 15% between 1960 and 2008. 

Rampell shows that grade inflation varies across different types of campuses.  Private schools have had more inflation than public schools; a private school student has an 86% chance of getting an A or B in any given class.  Grades are lower in Southern schools and schools with large engineering and science enrollments. 

Why have grades risen so much? Hard to argue that students are smarter (the trend on SAT scores is flat at best) or working harder (surveys actually indicate they are studying less).  No doubt some profs gave out higher grades in the late 1960s and early 1970s to keep folks like yours truly from getting drafted and sent to Vietnam.  But the Vietnam War was over in 1975 and this trend is continuing.  Another theory is that student evaluations are more likely to be used to evaluate faculty for tenure and raises, so faculty "buy" higher evals by giving higher grades.  I am not sure I buy that explanation either; some of the toughest graders in the Jenkins MBA program get the highest student evals.