It's three o'clock in the morning, and the Ec 10 problem set you have postponed all week is due in section today.

Your blockmate owes you a favor and finished the same assignment more than an hour ago.

This scenario, familiar to many Harvard students, almost inevitably results in a quick, guiltless copying of the homework.

That's not cheating, many students say, Professors encourage cooperation on assignments, especially in science, math and economic courses.

Cooperation, students add, has often been extended to duplicating problem sets, seeking help on take-home exams and even copying answer keys to homework.

But in the wake of recent national surveys (see graphic) which cite an increase in cheating on college campuses, students, professors and administrators are questioning the definitions and limits of cheating at Harvard--and whether students observe them.

Many students say that the absence of an honor code or a clear set of rules regarding cheating at Harvard has left undergraduate students wondering about what does and what doesn't constitute cheating.

University policy

It is during the mandatory Dean's meeting in Freshman Week that students receive their first dose of the University's expectations for proper conduct and integrity.

Besides a one-hour expository writing session on plagiarism later in the year, that is the extent of the administration's explanation of cheating.

"Students come away with a pretty good understanding of what plagiarism means within this particular subject matter," says Preceptor in Expository Writing Gordon C. Harvey. "But we don't say anything about the difficulties that arise out of collaboration."

Students say that this ambiguity blurs the lines of ethical and unethical behavior.

"I don't know if have ever cheated," says one student who requested anonymity. "I am totally unaware of how Harvard defines it."

The University's position is that defining the limits of acceptable academic behavior is up to professors and to the individual consciences of students.

Many who teach sciences, mathematics or economics encourage group participation in problem sets. Students are led to rely on this sort of collaboration--often for their grades.