I have 500 students. I can’t fit that many people into any room on campus. There is no amount of office hours that would allow me to connect with them all. Many of the students who ask questions on Piazza just wouldn't get the opportunity to ask them otherwise. Maybe they couldn’t make it to office hours; maybe they didn't get the chance to talk to a TA because it was so crowded in class. Now they can get answers to their questions 24 hours a day online. Hundreds of them are using Piazza. Some read every post on there—I see them having ‘post feuds’ (laughs). So they enjoy it. They definitely take advantage of it.

There are two key differences: First, the piazza platform is very intuitive to use so it’s easy for TAs and students to start using it right away. Second, I also really like the ‘wiki’ format where everyone contributes to one common answer – this is what really saves time because then you don’t have to read through a giant thread of comments.

I’ve found that if you hang back, other students will jump in. My TAs last quarter were less active, and the students really picked up their slack. It took some time, but eventually the students seemed to realize, ‘Well, the TAs are not going to answer this, I guess I’ll jump in!’ At first I wondered if the TAs should be participating more, but then I thought, ‘No, it should be the students!’ And it was really interesting: When we got to the end of the quarter, there was a clear correlation between students’ participation and their grades. My top performers were people I knew by name, because they were also my top participants on Piazza.

One thing that’s kind of cool is that before I give a lecture, I monitor the chatter on Piazza, and if something has come up a couple of times or is controversial or getting a lot of views, I’ll address it in the lecture. It’s like real-time teaching. Some questions are trivial, of course, but sometimes I think, ‘Well, that’s a very deep question, I should have made that clearer, I missed the boat.’ It’s a valuable way to take the pulse of the class. And to find out of there was a major typo in a homework assignment, something I need to correct!

It’s made things more efficient. Now, at the beginning of the quarter, I tell my students to direct all their questions to Piazza—that they should not need to email a TA unless it’s about a very personal problem. Previously, we’d get flooded with so many of the same questions on the night before an exam and would have to answer them all individually, copying and pasting the same responses. Now I just tell each TA to answer a few questions on Piazza, which takes twenty minutes.

Yes. And we rotate duties, so a TA may be proofreading an exam or problem set one week and answering questions on Piazza the next week. As a result, they all have more time to grade, give feedback on lab write-ups, and hold office hours.

One of the things that’s been helpful is that whenever I make suggestions, you guys follow through on them. That’s what I’ve told other professors. I’ll say, ‘If there’s something you don’t like, tell them.’ Some of the changes—you can now post JPEGs, for example—have made things even easier, especially for organic chemistry, where I’m drawing structures and things. Even my students now post images that they drew and photographed with their phones!