“Cheating has taken place for who knows how long,” the schools chancellor, Dennis M. Walcott, said Monday morning in an interview on the John Gambling show, a radio program in New York. “Now with technology, and that’s why we banned cellphones; people have the ability to use new technology to try to cheat. So people are always trying to think of new ways to do things. It’s not acceptable.”

The revelations that dozens of Stuyvesant students had cheated on tests not considered particularly challenging for them were the latest example of the competitive pressures inside top schools. In December, officials uncovered widespread cheating on an English final exam by students at a well-regarded school outside Houston; hundreds of students were believed to be involved, and 60 were disciplined. An SAT cheating scandal on Long Island last year, in which test takers used fake IDs to impersonate other students, led to nationwide changes in the way college admissions exams are administered.

Cheating has been a difficult issue for Stuyvesant for some years, one that students have not shied from confronting. An editorial in the Stuyvesant newspaper, The Spectator, two years ago pinpointed a culture of “academic dishonesty,” whose roots derived from an emphasis on numerical success, like high test scores, rather than on valuing learning that is not as easy to measure.

“There is too much weight put on a couple of numbers to determine your worth as a student and a human being,” said Benjamin Koatz of Forest Hills, Queens, who graduated in June and is headed to Brown University. “And the highly competitive nature at Stuyvesant lends a hand in that, but it is really endemic to the system.”

Mr. Koatz said that when a couple of points can make the difference in getting into an Ivy League school, “then there is an incentive there, especially since most of the students come from families where the goal is ‘Ivy League school or bust’; you either go to an Ivy League school or you haven’t lived up to your potential.”