Students gather in small group settings to solve problems during class. CS 20 uses a flipped classroom technique to cover and review material taught in lecture.

For nearly 20 years, computer science professor Margo I. Seltzer ’83 taught the course Computer Science 161: “Operating Systems” in a conventional lecture format.

But teaching from the front of an auditorium that—especially after lecture videos became available online—held dwindling proportions of the enrolled students did not seem to be the most effective use of class time.

As a result, Seltzer decided to experiment with “flipping the classroom” this semester. For a third of the course, Seltzer is providing material in pre-recorded lessons for students to watch online, and instead using the two weekly 90-minute sessions for group work, coding exercises, and class discussions.

Faculty of Arts and Sciences classes have promoted group work in the classroom for years, but the flipped classroom method goes a step further by moving the traditional lecture out of the lecture hall. Several other CS professors say they are considering how to adopt the concept to address a lack of attendance in their own courses.

Now, as SEAS anticipates a move to more spacious quarters in Allston, computer science professors may soon have access to the spaces necessary to grow the flipped classroom model. But professors acknowledge the virtue of the traditional lecture format, and say there are fundamental limitations to scaling the model for larger courses that cannot simply be overcome with more physical class space.

“A COLLABORATIVE ENVIRONMENT”

In spring 2012, computer science professor Harry R. Lewis ’68 first introduced the flipped classroom to SEAS in his new course Computer Science 20: “Discrete Mathematics for Computer Science.” In a course for concentrators who lack mathematical background, Lewis said the method of “coached problem solving” is particularly effective.

“What we really want to teach people is not so much facts, but how to think about approaching problems and solving them,” Lewis said.

One year later, Lewis’s idea is beginning to catch on. A Tuesday afternoon in a CS 161 class finds Seltzer’s students working in pairs to download the code for a new problem set and analyze one of the functions in detail.

With the students spread across the room in tables of four, Seltzer and the course’s three teaching fellows wander around taking questions, occasionally pulling up one of the six movable whiteboards in the room to illustrate a concept.

Seltzer said that the new format fosters greater engagement and a sense of community among herself, students, and the teaching staff.

“In a traditional lecture, when you try to get interactive conversations going, the people who are most in control and most comfortable with the information are those who are most likely to answer questions and engage,” Seltzer said. “In the flipped classroom...the groups that are struggling and that actually need help, those are the ones with which the TFs and I are engaging.”

Yaniv Yacoby ’15, a student in CS 161, said that sitting in a flipped classroom encourages him to think critically about the material.

“It allows you to think for yourself and figure out exactly why existing infrastructures are in place instead of receiving information exactly as it is,” Yacoby said. “I thought it was very, very effective.”

FILLING SEATS IN CS