Nancy Weiss Malkiel, dean of the undergraduate college at Princeton, said the policy was not meant to establish such grade quotas, but to set a goal: Over time and across all academic departments, no more than 35 percent of grades in undergraduate courses would be A-plus, A or A-minus.

Early on, Dr. Malkiel sent 3,000 letters explaining the change to admissions officers at graduate schools and employers across the country, and every transcript goes out with a statement about the policy. But recently, the university administration has been under pressure to do more. So it created a question-and-answer booklet that it is now sending to many of the same graduate schools and employers.

Princeton also studied the effects on admissions rates to top medical schools and law schools, and found none. While the number of graduates securing jobs in finance or consulting dropped to 169 last year from 249 in 2008 and 194 in 2004, the university attributed the falloff to the recession. (Each graduating class has about 1,100 students.)

But the drop in job placements, whatever the cause, has fueled the arguments of those opposed to the policy. The grading change at Princeton was prompted by the creep of A’s, which accelerated in the 1990s, and the wildly divergent approaches to grading across disciplines. Historically, students in the natural sciences were graded far more rigorously, for example, than their classmates in the humanities, a gap that has narrowed but that still exists.

Image But Jacob Loewenstein said, “There are tons of really great schools with really smart kids applying for the same jobs.” Credit... Suzanne DeChillo/The New York Times

Some students respect the tougher posture. “What people don’t realize is that grades at different schools always have different meanings, and people at Goldman Sachs or the Marshall Scholarship have tons of experience assessing different G.P.A.’s,” said Jonathan Sarnoff, a sophomore who sits on the editorial board of The Daily Princetonian. “A Princeton G.P.A. is different from the G.P.A. at the College of New Jersey down the road.”

Faye Deal, the associate dean for admissions and financial aid at Stanford Law School, said she had read Princeton’s literature on the policy and continued “to view Princeton candidates in the same fashion  strong applicants with excellent preparation.”