The teaching staff of Life Sciences 1b is investigating possible disciplinary measures for “course-wide cheating,” according to an email sent by teaching fellow Iain J. MacLeod to his students last week.

MacLeod wrote that the teaching staff believes that students were using a Facebook group called Ls1b to cheat on questions during lecture quizzes and breakouts—questions that are asked during lecture and answered via clickers registered in students’ names.

“It has come [to] our attention that a large number of LS1b students are using the LS1b Facebook group in order to share the answers to the clicker and lecture quizzes, while the quizzes are taking place,” MacLeod wrote.

He added that, as a result, the grading scheme for the course is being revised due to “course-wide cheating.”

Soon after the email was sent, the Facebook group was deactivated.

Caroline M. Weisman ’14, a member of the Facebook group, said that the accusation was unfounded. She said that both preceptors encouraged collaboration during breakouts.

“During breakouts there was audible chatter,” Weisman said. “People would be talking to everyone around them. It was encouraged to collaborate on breakout questions.”

Another member of the Facebook group, who asked to remain anonymous due to concerns about potential disciplinary action, said that during quizzes, teaching fellows would patrol the aisles and most students would close their laptops.

“My main purpose for the group was to express frustrations about the class,” he said. “Personally, I never used it to cheat.”

According to another anonymous member of the Facebook group, for the first couple of weeks, group chat was used to collaborate on problem set questions and clicker questions. But soon after, the number of members became too large to host chats, as the group had over 300 members at its peak.

He said that the group was “a social center” for collaboration to talk about questions students had about the course and how to solve problem sets. He said he never witnessed answers to problem sets being directly given.

“Obviously, we have no objection to Facebook pages for you to vent your frustrations about the course,” MacLeod wrote. “Yet the university takes academic dishonesty extremely seriously and I’d hate for any one of my students to be brought to the attention of the Ad Board.”

Weisman explained that during the second half of the semester, students used the group as a forum via which to petition for a change in the course’s grading policy.

Preceptors Casey Roehrig and Lynne M. Mullen declined to comment.

Human Evolutionary Biology Professor Maryellen Ruvolo, who co-teaches the course, could not be reached for comment.

—Staff writer Nathalie R. Miraval can be reached at nmiraval@college.harvard.edu.