How I Use Slack in My Courses — a 3 Year Reflection

My first semester as a professor, I wasn’t prepared for the volume of p̶e̶d̶a̶g̶o̶g̶i̶c̶a̶l̶ ̶c̶h̶a̶l̶l̶e̶n̶g̶e̶s emails I would face.




I quickly discovered that the velocity of student emails near an impending project deadline can transform the notification tones on my phone into a dystopian EDM anthem. Even worse, the emails are often redundant — I answer the same question to multiple students across multiple weeks.

This just about sums up my email experience during the semester.

There has to be a better way, right? In Summer 2015, I started looking for better platforms to engage students in my courses. My criteria:

  • I wanted to shift the conversations in my course out of my inbox and into a space that I could refer back to later in the semester.
  • I wanted a consolidated space where I could answer questions once for everyone.
  • I wanted a space in which (maybe… just maybe) students could help each other when I wasn’t available to help them myself.

I initially settled on Slack because of success I had in a research collaboration (or maybe I just liked the interface). Fast-forward to today, and I’ve now used Slack across 5 different courses in our Computer Science curriculum. And while I hate teaching without it now, integrating any new tech in the classroom comes with its bumps. Here are six things I’ve learned in 3 years of Slack use.

(If you want a tl;dr, scroll to the bottom for a summary)

1. When I use Slack, I commit to it (RIP email).

Education doesn’t have magical tech bandaids that just work. Slack is no different. It turns out that students, like all people, are creatures of habit. Just because you send your students invites to Slack doesn’t mean they’ll sign up or pay attention. Some strategies I use to incentive attention:

  • I post lecture notes / activities on Slack.
  • I post a 1st day survey that needs to be completed by the next lecture (usually a “Tell me about yourself” survey)
  • I tell my students that I’ll send course information via Slack, not email (and actually stick to that promise).
  • I don’t make assumptions about Slack’s usability. I tell my students to set their notifications! I run an in-class demo to show students how to add channels in class.
Slack for the 2017 HCI class. Across 28 students, we ended up with nearly 6000 messages over the semester

2. I think carefully about the channels I set up.

  • I don’t make too many channels unless I have a plan for how to use them. Early on, I created a new channel for every lab/homework in the course, hoping that students would use the space to discuss each assignment. Over time, I’ve found that the more I fragment discussion, the more likely my platform is going to turn into a ghost town. Unless you have a specific plan, a high-level #homework channel is usually enough.
  • I take advantage of non-critical channels. Two channels I create in my HCI course are #hci_ads and #hci_inspiration. In those, I post every course-related internship/job and interesting article that flies by my screen. This content would have been annoying as a barrage of emails, but works in a Slack channel. If most students ignore the content, that’s perfectly fine to me. But for the students who care, it’s a priceless resource. It lets my passion for the topic shine as well. My classes are always better for it.

3. I think differently about assignments.

If you use Slack as just an email replacement, I don’t think it’s worth the effort. Use the platform in a way that leverages the low-barrier social interaction. Some ideas:

  • When tackling a complex topic, I’ll assign the class to post a link to a resource that helps them understand it (often in a #resources channel). In CS 1, there’s nothing like seeing 13 different gifs representing recursion. Philosophically, I love this as well. I’m not arrogant enough to think that I can speak to all students all the time in a way they understand. Empower them to see different perspectives of complex topics! Later in the semester, I often point students back to these examples as review.
Shoutout to my Fall 2016 students (I think) for sharing this magical gif on Slack to help explain recursion.
I’m telling you, this format is awesome. My guests often love the conversation. These questions were created for Adam Marcus.

4. I’ve found that it’s better during class than outside of it.

I used to consider Slack as a platform for communication outside the classroom. I’m here to to tell you that it’s at its best during class. I’ll often code live examples in class and then immediately put them up on Slack for students to interact with. There’s also no more “I’ll email that link later” or “I’ll post this code on Moodle sometime later today (if I remember)”. Slack is the fastest way for me to share content in class, and it empowers students to use their laptops for good.

Posting links for students to follow along with live coding demos

5. I’ve found that it enables invisible, group communication.

When introducing a platform like Slack, it’s worth remembering that you only get see the public messages. In my 2017 Human-Computer Interaction class, the 28 students (and me) sent around 6000 messages during the semester… but ~80% of all messages were in private channels and messages! Would students have used their own platforms to coordinate on their group projects? Maybe — but I like to think that providing a platform for communication lowers barriers for interaction.

Slack’s data dashboards also yield insight about my course that would be difficult to get elsewhere. More challenging assignments tended to yield more messages. You can almost get a sense of the topology of the course by seeing the change in message volume below…

A plot of the number of Slack messages over a few weeks of the semester. Can you guess when the major deadlines were? That September 26 deadline was … uh… not my best designed assignment

By the way, I don’t just use this data as an instrument for reflection. As a junior faculty member scrambling towards tenure, it’s nice to be able to quantify anything that might reflect course engagement.

6. I use it to introduce playfulness in my classes.

If I were a researcher in this area, I’d propose the measure time-to-prof-emoji. Typically, I see a thumbnail emoji of myself pop up within the first two weeks. In one semester, an internet-savvy group of students managed to dig up a picture of me from when I was 20 and use it liberally through the semester (thanks internet). Note that once an emoji of you is created, that emoji will rule all emojis and be used at least 90% of the time.

When students make an emoji out of me, there is only one suitable retaliation — make emojis out of them.

Learning can be fun. Different professors have different philosophies for the atmospheres they want to create in the classroom, so this one might not be for you. But personally, I’ve found a correlation between “frequency of Prof. Peck emojis” and “willingness to ask questions as soon as they rise”.

Different Classes, Different Experiences

When I first introduced Slack, I thought “Everyone will help each other and talk all the time and it will be great!”. The reality is that different groups have wildly different personalities…. and frankly, that communal learning atmosphere rarely emerges organically. But with the right nudges and integrations, I’ve come to love the benefits. To summarize the main points from this article:

  • If you use Slack, throw away course email and commit to it.
  • Don’t create too many channels for critical information (homework)
  • Leverage the creation of new channels for non-critical information (interesting articles, etc.)
  • Use Slack outside class to create assignments that involve an interactive component between students (it’s what Slack is good at!).
  • Use Slack during class as a low-barrier mechanism to share information (both from you to students as well as from the students to you).
  • In project-based classes, Slack will help facilitate behind-the-scenes communication between groups.
  • Posting metrics can provide additional feedback about assignments.
  • Use Slack as a way to make learning more playful.

I am an Assistant Professor of Computer Science at Bucknell University. You can find me on Twitter at @EvanMPeck or read more posts I have about teaching or research. Please let me know if you end up using some of this material (feel free to!) — I’d love to keep track!