"If chances for getting caught are fairly low, it's fair to say that in a random class of 50 to 100 students, about 10 percent are cheating," Aiken says. " I have anecdotal evidence from colleagues that have used MOSS that confirms it--10 percent is what you get when people are supposed to be doing the right thing."

Not all colleges employ plagiarism detection software in their computer science courses. Course instructors still manage to catch code similarities when they grade problem sets by hand--as a group of Dartmouth students recently learned.

Last month, Rex Dwyer, a visiting computer science professor at Dartmouth, accused about 40 students in his introductory computer science class of stealing answers to a homework assignment from the course's website.

Dwyer alleged that the students had accessed solutions to a particularly difficult homework assignment on the site, which had previously been protected with a password, according to the student newspaper, the Dartmouth. Dwyer had not changed the password after a class demonstration.

Dartmouth's main disciplinary committee, the Committee on Standards, is still investigating the charges.

Cooperation and Collaboration

But Harvard is making no new effort to curb cheating in courses outside computer science.

Dean of the College Harry R. Lewis '68, who also teaches Computer Science 121, says that computer science has to be considered separately.