This year's FAQ for CS50, Harvard University's largest course, featured this statement: "Unlike last year, students are encouraged to attend all lectures in person this year."
Encouraging the 800-plus students enrolled in the introductory computer programming course may sound typical. But it's a reversal for the course, which is regularly described as one of the most popular and rigorous at Harvard, and a model of effective teaching.
Last year David J. Malan, the Gordon McKay Professor of the Practice of Computer Science, made attending lectures optional. In a very public version of flipping the classroom, Malan said it would be fine for students to watch videos that are made of each lecture.
In an essay a year ago, Malan wrote that he was requiring students to attend only the first and last lectures of the course. And he questioned the value of saying everyone should attend every lecture.
"Sitting in Sanders Theater, beautiful though it may be, has never been a particularly effective way to learn complex material," Malan wrote. "Indeed, insofar as the material within a lecture tends to be cumulative, whereby example i assumes an understanding of example i-1, it’s all too easy for a student to miss or misunderstand some detail, the result of which is a suboptimal experience in that lecture thereafter …"
He added, "And sometimes we all just need a moment for something to sink in. If only there were a way to pause or rewind! Simple though those features may be, I daresay we’ve been nearing the point for some time whereby it’s a better educational experience to watch CS50's lectures online than attend them in person. Indeed, with pause and rewind buttons accompanied by searchable full-text transcripts of lectures, variable playback speed and hyperlinks to related resources, all of which lend themselves to more active engagement with the course’s lectures, it’s hard to argue that sitting and listening live in a theater is better."
Last year, Malan recorded the lectures a few days in advance of the live class session, so students could have access in advance, if they wanted. And he made clear that this was an acceptable way to learn the material covered in each lecture.
In an email to Inside Higher Ed, Malan said that there was no decline in learning outcomes in the course, even as the number of students who attended lectures in person was not as high as in past years.
Malan also said that he realizes there will still be students who have scheduling conflicts with other courses such that they may rely on the recordings, which will be produced live this year. And other students may benefit from watching the recordings after attending the lectures in person.
So why revert to telling students they are expected in class?
"Enough former students reported that something was missing, not just the students themselves but the energy of an audience, that we decided to bring [encouraging students to attend] live lectures back this fall," Malan said.
One of Harvard's satire websites has suggested that -- following Malan's shift -- another course should do the opposite.