How To: Live Lecture Backchannel

In the pre-covid pandemic times, I introduced a backchannel to my CS1 lecture using our class forum. And I’ve continued this practice ever since, including during the pandemic, remote teaching. This post discusses the why, the how, and what my students think of the backchannel. It also includes considerations if you are thinking of adding the practice to your own class.

[Also posted on medium.]

For a little bit of history, I first tried creating a backchannel using a web chat app. This did not work. The students rarely used it. I think it was a combination of the app having some bugs and it being “yet another tool” that was part of the class’s rather large tool ecosystem. After that failed attempt, I switched to our class forum, Piazza. The class forum worked, and I’ve been using it even during the pandemic imposed remote teaching.

Why?

There are many reasons to add a lecture backchannel. For me, the biggest reason was lowering the barrier to ask a question. Asking a question in front of others is intimidating. Asking in front of 100s is likely worse. A feature I love in Piazza is asking questions anonymously, which the vast majority of students use. The backchannel also enables asking questions after the topic has already passed in lecture, so a question never goes unanswered. This lower barrier of entry also means more questions from a larger group of students. More questions from more students means a better sense of what students find confusing. It also serves as a record of many of the questions asked in class that students and I can reference.

Despite the increase in the number of questions, it actually gives me back some control over when questions happen. I encourage my students to simply raise their hands and ask a question. However, sometimes those interruptions are not well-timed. Having a backchannel with a record of the questions allows me to incorporate when I answer questions. During lecture, I pause a few times and ask the teaching staff person keeping track of the forum if there are any questions I should answer. This request lets me use natural pauses for questions and reminds students that they can ask questions there if they do not want to raise their hand.

Finally, no question goes unanswered. If I run out of time in lecture, the questions are still in the class forum. I or a teaching staff person can go and answer them after lecture. Students sometimes even go back to a lecture’s particular post and ask their question there, rather than make a new post. I suspect it happens while they are watching the lecture recording.

How?

As I hinted at earlier in my post, we currently use Piazza as our class forum. Though with Piazza’s recent changes, I think my campus is exploring other options. However, I don’t think my process is tightly tied to Piazza.

Here’s the quick rundown of what I do. Every lecture gets its own post and is labeled “lecture” so it’s easy to search for. The subject line is something consistent, like “Class DATE” with an optional topic. The body of the post is short. It includes links to the slides, any links in the slides, and a reminder of the post’s purpose, like “Post any questions you have from today’s lecture here as a follow up post.” For the first few days of class, I remind students about the post before lecture starts, and while teaching over Zoom, we also pasted the link in the chat.

During lecture, I have a course expert(s) monitor the post. The expert is usually an experienced TA or my teaching associate (a staff member who supports the course). Notice, I said course expert, not just content expert. Students ask many different kinds of questions about the syllabus, course logistics, assignment clarifications, and concepts. This person(s) should be able to answer these questions on the fly, or you have multiple people monitoring the post, and together all course expertise is covered. This person(s) should also be willing to raise their hand if it’s clear several students want a question answered, and therefore the class as a whole would likely benefit from hearing it during lecture (or in the lecture video). And regardless of whether we answer the question in lecture, we also answer it on the class forum for future reference.

Finally, after lecture, we make sure to answer any lingering questions. I also recommend marking the post to notify you if it gets updated because, as I said earlier, sometimes students like to ask questions on the lecture posts even after the lecture.

Student Thoughts

The first semester I did this, I added questions about the backchannel to my end-of-semester survey. 46% of students said it was neither useful nor unuseful. I suspect because they didn’t use it, which was a common comment in the open textbox responses. Of those that had some opinion, 36% said it was useful, and 18% said it was unuseful.

Positive comments included how students liked that it was quick, easy, or convenient to ask questions. Multiple students mentioned appreciating the anonymous feature and not having to interrupt lecture to ask a question. Some students discussed using the posts as a study reference or another way to engage with the material and think critically. Another mentioned that seeing other’s questions validated that they weren’t alone in having questions and not getting the material immediately. Multiple students commented that sometimes someone asked a question they didn’t even realize they had until they saw it.

The most common negative comment was the “email spam.” The default setting in Piazza is to email the students about every activity on the forum. So it might be worth mentioning to the students that there are notification settings they can change to reduce the email. Other negative comments had more to do with the challenges of navigating Piazza’s interface. And finally, a handful mentioned the backchannel being too distracting during lecture. However, one such comment also acknowledged that it was on them to close the forum if that was happening.

According to the comments, response speed was critical. Multiple appreciated the speed of getting their questions answered. But others complained that the response was too slow. So speed is vital when it comes to this kind of backchannel.

As I already mentioned, based on these results, I decided to keep the backchannel and have kept it ever since. The positives outweighed the negatives, and I believe it is worth the resources.

Things to Consider

First, let’s talk about remote teaching. Even if we (hopefully) are past the emergency remote teaching that Covid-19 imposed on us, this is still something to consider. As we exit the pandemic, one of my hopes is to hold on to our willingness to question norms and reevaluate our pedagogy.

The backchannel was utilized about the same or more when we used it compared to pre-pandemic, in-person lectures. I’d say it was even more helpful to manage questions for all the reasons I stated above and more. The Zoom chat was not designed to easily manage question multi-threading.

There are two things to consider during remote teaching. First is should you share your screen? With Piazza, we could not because the teacher’s view showed the students’ names that were anonymous in the student view. The second is expect to remind students all semester to ask questions in the class forum rather than the zoom chat. I suspect this is not because students forget, but because the engagement distribution with the backchannel follows a Zipf distribution where some students use it a lot and the rest infrequently, once, or not at all. So of the students who have a question, it’s their first time for the vast majority, and they’ve forgotten the backchannel protocol.

If we set remote teaching aside, the primary question is if you have the resources to do this. Is there someone(s) that is a course expert that can be at lecture monitoring the class forum in real-time and paying attention to lecture enough to answer questions like “What did the prof just say was important to know about lists?” Does this person also have the judgment to raise their hand during class to ask a question that would benefit the entire class?

Second, are you willing to incorporate it into your lecture by actually checking with the person monitoring if there are questions? Remember, this both lets you better control when questions happen and reminds the students that this is a lower-stakes place to ask questions than just raising their hand. It will feel like you are slowing down your lecture. However, remember that the goal of lecture is for students to learn. And doesn’t getting better and more representative questions from students and addressing them help achieve that goal?

Conclusion

So that’s it, that’s why and how I do a backchannel in my lecture. However, in all honesty, the more I think about lecture, the less I’m sure it’s the best use of synchronous, in-person class time. This line of thinking has led me to consider what is the best use of that time and what changes I should make. Writing this blog post was partially to articulate the uses of a class backchannel and the “meta-why.” This way, I can better see how it could fit in whatever I try to do with synchronous, in-person class time.

How about you? Do you do something similar? Have questions about implementation that I didn’t answer? Any thoughts on how lecture should change?