Slack for (A)synchronous Course Communication

Contributing author Albert Y. Kim is an assistant professor of statistical & data sciences. He is a co-author of the fivethirtyeight R package and ModernDive, an online textbook for introductory data science and statistics. His research interests include spatial epidemiology and model assessment and selection methods for forest ecology. Previously, Albert worked in the Search Ads Metrics Team at Google Inc. as well as at Reed, Middlebury and Amherst colleges. You can follow him on Twitter @rudeboybert.

Contributing author R. Jordan Crouser is an Assistant Professor of Computer Science at Smith College. He is published in the areas of visualization theory, human-computer interaction, educational technology, visual analytics systems and human computation. For more information, visit his faculty page.

Contributing author Benjamin S. Baumer is an assistant professor in the Statistical & Data Sciences program at Smith College. His research interests include sports analytics, data science, statistics and data science education, statistical computing, and network science. For more information, visit his faculty page.

You might have heard of Slack before. But what is it? Is it email? Is it a chat room? Slack describes their flagship product as a “collaboration hub that can replace email to help you and your team work together seamlessly.” In this blogpost, we’ll describe how we’ve been using Slack for asynchronous course communication, as opposed to the synchronous course communications afforded by Zoom and other remote conferencing platforms.

Why do we stress (a)synchronous? The brick-and-mortar constraint of having everyone working at the same time is unworkable under the unfolding COVID-19 pandemic. Across the world, support staff, faculty, and students have suddenly been forced to convert to a remote learning model of education. In order for this model to be successful, flexibility is needed to ensure equitable learning experiences with respect to differences in time zones, suitability of student learning environments, internet access, and many other factors. In order to ensure this flexibility, many instructors are recognizing that some portion of their courses must be delivered in an asynchronous fashion, on top of the synchronous nature of regular lecture and meeting times. 

Before we discuss how we’ve been using Slack, we must explain how Slack is organized.

How is Slack organized?

Slack is organized into workspaces, which loosely correspond to a “team” of individuals (such as a research or special interest group). In our case, this will be an individual course. When using Slack from the Desktop or Mobile app, a list of your workspaces appears in the left-hand vertical menu bar. For example, of the 8 workspaces highlighted in red, we are currently viewing the “220” course workspace:

Within each workspace are channels (identified with hashtags), highlighted here in blue. You can think of channels as forums corresponding to topics. In this example, we have #general (announcements), #questions, and several others. Different stakeholders can join each channel, and channels can be designated public or private as appropriate. Note how the #problem_sets channel has a lock icon, indicating that it is private (to just instructors and graders).

Additionally, within each workspace are direct messages (DMs), highlighted in green. You can think of DMs as group text messages. Unlike with channels, people cannot later “join” these conversations.

What are the benefits of Slack?

Slack’s primary benefit is centralization and organization of communications, which helps to minimize inefficient context switching:

For example, if we want to ignore messages related to the 220 course and focus our attention on the 293 course, we can do so easily. This inherent compartmentalization of communications relating to courses is especially helpful when managing asynchronous communication across multiple courses, the challenges of which have been amplified during the recent outbreak of COVID-19.

Second, Slack facilitates the posing and answering of student questions via channels dedicated to discussion boards. This is a welcome feature of Slack given the importance of (a)synchronous communications in light of COVID-19.

Note that Slack is certainly not the only platform that has such functionality; other platforms include Moodle, Piazza, and Discord

Third, the benefits of Slack increase not only as the number of team members grows, but also as the number of distinct groups of team members grows. For example, this semester’s two sections of Smith College’s SDS/MTH 220 Introduction to Probability and Statistics have 79 students who form 31 term project groups, 2 instructors, 2 lab instructors, 2 graders, and 2 in-class teaching assistants. By carefully constructing both private and public channels and direct messages, we can  localize communications in their appropriate destinations. This is critical at a time where we can’t meet in person, nor can we easily meet at the same time.

Fourth, the more casual nature of Slack interactions versus email reduces instructor/student barriers. For example, less time can be spent choosing appropriate email greetings and signoffs. Additionally, Slack’s use of newer modalities of communication like emojis and GIFs can further facilitate expression at a time when maintaining open communication is paramount.

Other benefits of Slack include (1) seamless transition between Desktop and Mobile interfaces; (2) a growing ecosystem of 3rd party applications to integrate with platforms such as Zoom, GitHub, PollEverywhere, Google Drive, and Dropbox; and (3) unlike Moodle or Piazza, Slack is widely used in industry. While we won’t argue that Slack is a skill, familiarity with it certainly won’t hurt students as they enter the workplace.                   

What are some pitfalls of Slack?

As with any communication platform, Slack has its share of potential pitfalls:

  1. There are cognitive costs associated with switching to Slack-based course communication, and student buy-in can vary depending on (1) general comfort with technology and (2) the use of Slack within other courses at your institution or department.
  2. Notifications settings really matter: students who only use Slack via their browser often miss messages sent between lectures if their email notifications aren’t set. Students who use the Desktop or Mobile applications encounter this issue far less often, but this does require installation of these interfaces.
  3. Since Slack was designed for tech companies rather than for education, it is consequently not FERPA compliant. Thus, certain sensitive communications should not take place on Slack. 
  4. While Slack offers a “freemium” version, it caps access to the most recent 10,000 messages and 5GB of file storage. To exceed these caps, monthly per user fees must be paid. 

When to make the switch

Should you switch to Slack right now (during the COVID-19 pandemic)? Our answer: if you have an existing method that gets the job done, probably not. Switching your communication tool amid the stress currently facing staff, faculty, and students may cause more harm than good. However, you may want to consider the following reasons we think you should use Slack in future courses: 

  • Do you prefer having your communications centralized and compartmentalized?
  • Are there multiple groups to coordinate within your team: instructors, teaching assistants, graders, students, and various groupings thereof?
  • Are you looking for ways to make communication between students and faculty feel more accessible?
  • Does your course involve collaborating on code, either directly or via GitHub?
  • Do other instructors in your department or institution use Slack?
  • Do you hate email?

As your answers to these questions tend toward yes, the case for Slack gets stronger. At our institution, we have been vocal advocates of using Slack in the classroom. The increased importance of (a)synchronous communication brought on by the COVID-19 pandemic has further reinforced our belief in the benefits that Slack can provide for course communication.


As with any large change in workflow, getting started is often the hardest part. To this end, R. Jordan Crouser has created the following quickstart guide for Slack: Getting Started with Slack for (a)synchronous course-based communication. 

Additionally, for a live demonstration of Slack and many of its useful features, check out this video. The content of much of this post is based on Albert Y. Kim’s 2019 Symposium on Data Science and Statistics talk Using Slack for Communication and Collaboration in the Classroom.

Online Strategies due to COVID-19, Part 2

In this series of posts, the StatTLC blog team describes how we are managing with the abrupt changes to our courses. In this, we share some of our decisions (and the thinking that went into them), the tools we are using, and tips. We are teaching a diverse set of classes this semester at institutions with many different technology tools. We hope that you find this useful as you make some decisions for your classes moving forward in the time of COVID-19.

Adam’s Situation

Calendar: My institution is on trimesters, so instead of switching a class to an online-only format midstream, we are starting our spring term courses online. We hope to be in person for the second half of the spring, but I doubt that will happen.

Classes: Introduction to data science (undergrad, 34 students), Statistical consulting (undergrad elective, 15 students)

Switched to: Synchronous online classes on 3/11/2020

Technology: Institution uses Moodle, Zoom/Google Hangouts Meet, Panopto; I’ll also use GitHub and Slack for data science.

Adam’s Thoughts

With my “extended” spring break I am making changes to my two courses for online delivery. Both courses require students to use R extensively. In consulting, students work on a group project all term. In data science, students are learning a lot of fundamental ideas and solving problems for homework. I’m a bit worried about the tech requirements for these courses, but there is no way around it without devising completely new courses, which is out of the question. Luckily, my institution already has an RStudio server that students can use remotely. The IT department is also working to get all students internet access and equipment, but who knows how that will go in practice.

My consulting course was supposed to meet once a week for two hours. This allows students to meet with their groups and check in with me. I plan to schedule 30-minute weekly check-ins with each group. I’ll also be using Moodle heavily to guide project progress and have students submit weekly journals where they outline their progress and reflect on assigned readings.

To adapt data science for remote delivery, I plan to do the following:

  • I need to set student expectations from the start and make sure that we are all in this together. I plan to be very transparent, and openly admit there will be technical snafus and unforeseen struggles in this new format. I also really need to beef up my syllabus with a lot of new statements about these expectations.
  • I am going to shamelessly use existing content, recording new lectures via Panopto only when necessary. These videos will be viewed asynchronously. 
  • Like Laura Ziegler (Part I), I plan to make weekly videos with a recap of last week and a look ahead to this week.
  • I’ll use Slack for discussion outside of class and to answer questions during office hours for students who would prefer that type of Q&A platform.
  • “Class time” on Mondays and Fridays will be similar to office hours, where I answer questions and clarify concepts. On Wednesdays, I will have students work in groups. To allow asynchronous work, after the first week students don’t need to “attend” class, but the assignment will be due the next day.
  • I’ll use Zoom for office hours.
  • I’m abandoning tests in favor of case studies, where students will either write a blog post or record a presentation (using Panopto or similar) that they submit to me.

Steve’s Situation

Classes: Biostat Methods II (MS, about 20 students), Data Visualization in the Health Sciences (MS elective/service course, 6 students)

Switched to: Synchronous online classes on 3/11/2020

Technology: Institution uses Canvas and Zoom

Steve’s Thoughts

After teaching a total of 10 sessions online sessions, here are my thoughts/comments:

My courses are all transitioning to synchronous online sessions at their regularly scheduled times through my university’s Zoom license. So far, Zoom has included enough functionality to allow a fairly painless switch to the online setting. Some of my comments may be specific to my university, so I apologize if not all functionality works at your institution. Main topic of each comment is in bold for easier scanning.

  • Scheduling all Zoom class sessions through my course Canvas pages (Zoom Conferences app) has made it simple to provide students with the appropriate meeting links. One recurring meeting for Monday’s sessions, and one recurring meeting for Wednesday’s sessions. I believe you can also set a static meeting ID so in theory students could use the same exact link for all sessions. Scheduling through Canvas automatically notifies students of the meeting times and saves me the time of announcing the link before every class session.
  • When scheduling Zoom meetings, there is an option to automatically record the class session to either the local computer, or if your license allows it, to the cloud. Once we received permission to record to the cloud, this option was strongly preferred because you can set it to automatically transcribe the audio. While I expect most of my students to show up for the live session, I like the option to upload a recording just in case a student is without internet access or runs into technology issues during the scheduled class time. 
  • I set my Zoom meetings to automatically mute all students upon entering to avoid having a bunch of open microphones as people connect. Students are allowed to unmute their audio/video at any time if they have a question or comment (which works fine in my small classes, e.g. < 20 students). Otherwise, students can interact by using the “hand raise” button or the “clap” emoji which looks like a small hand raise. I can see these indicators by keeping my “manage participants” box visible at all times on one of my two monitors. Additionally, I keep the “chat” box open and visible at all times as well in case students are more comfortable typing than speaking. I am considering transitioning to requiring students to use their video, as sometimes I will ask a question and get no response at all. Two-way video may be important for engagement. 
  • Most of my class sessions involve a mix of verbal lecture, presentation slides, code examples, writing on the board, and exercises for students. Zoom’s presentation tools make it possible to continue using these methods. The screen sharing option in Zoom allows me to share my computer screen, which includes my slides and my R session. While sharing, I typically click the “Annotation” tab and use the “spotlight” feature to highlight my mouse. This makes it easier to track as I move it around the screen to “point” at certain things. 
  • Finally, for a virtual whiteboard, Zoom has a few different options. If you have an iPhone/iPad that you are comfortable writing on, you can share your device’s screen by clicking screen share in Zoom and choosing the iPhone/iPad option (instructions provided by Zoom from that point). Personally, I use the touchscreen on my Chromebook to create a digital whiteboard. To do this, I join the Zoom conference on my Chromebook and share my note taking app with the conference (I use Squid). This allows me to write on my Chromebook tablet with a nice stylus and have the result appear to my class in real time (the delay is very minimal).

Laura’s (L.) Thoughts

For anyone who knows me, I’m very much a people person. I say this because I was a little bummed when I realized that I was only teaching online for the 2019-2020 school year. However, in the wake of recent events (and especially because I’m taking on additional in-person classroom (my kiddos…so is that 2 additional courses?? 🙂 ), I feel I can offer tips and tricks into delivering an online course.

Tip #1: Communication is key!

While this may come as no surprise, I feel it is even more key in the online environment. Communication includes:

  • Instructions on how to navigate the online course, if they aren’t used to doing so (e.g., course overview and orientation). For example, provide a course structure for the rhythm of each week/unit (see this example from my introductory course). 
  • Updating expectations and (possibly) grading for the alternative mode of instruction. Things to think about are should they post questions in the Q&A or via email? How will you handle requests for extensions? Who should they contact first if they have questions: instructor or TAs?
  • As Laura Ziegler said, once a week (at the minimum, twice at the maximum) announcements about the week, upcoming assignments, upcoming assignments, and other important notes. 
  • Providing clear directions on all learning materials.
  • Offering timely, constructive, and frequent feedback on assessments. 
  • Responding to questions or posts in a timely manner (within 12 hours, minimum, and no more than 24 hours, maximum).

For other tips, see the recent StatTLC post by John Haubrick on instructor presence in the online classroom.

Tip #2: Create collaborative keys via Google Docs for activities.

If you have activities in class, move the activity to a Google Doc and have the students create the answer key as a class (we call them collaborative keys). Then the teaching team (instructors and/or TAs) can monitor the key to make sure the responses are on the right track and pose any additional questions. This offers an asynchronous, but effective, method for delivering active learning materials. 

We have been doing this method for a while in our flipped classrooms and for our online courses. It works better in the online environment than in in-person, and it’s actually a beautiful thing to see. There are discussions among the students, students helping other students out, questions being asked that are beyond the question that is asked, etc. We require students to post at least once (although, many go above and beyond that). Here is a document that includes (1) assignment instructions (that has a link to an example Google Doc collaborative key for our Week 1 activity) and (2) “How to contribute to the collaborative key” details on how to participate on the key. 

So, if you do have in-class activities, consider using Google Docs to create a community of learners.


This concludes our editor series on transitioning to the online environment during the COVID19 times. We hope that some of our thoughts and experiences are useful as we all try new things to adapt to the current situation. Feel free to share your thoughts in the comment section below or contact us to contribute a post of your own.

We hope that you and your families remain safe and healthy.

Online Strategies due to COVID-19, Part 1

In this series of posts, the StatTLC blog team describes how we are managing with the abrupt changes to our courses. In this, we share some of our decisions (and the thinking that went into them), the tools we are using, and tips. We are teaching a diverse set of classes this semester at institutions with many different technology tools. We hope that you find this useful as you make some decisions for your classes moving forward in the time of COVID-19.

Doug’s Situation

Classes: Introductory Statistics (algebra-based, about 80 students), Introductory Probability (calculus-based, about 20 students)

Switched to: Asynchronous classes (with synchronous office hours and review sessions)

Technology: Institution uses Moodle with Collaborate Ultra, videos made with a variety of free and open source software that are posted to YouTube

Doug’s Thoughts

  • The introductory statistics courses I teach have a course coordinator – this has added an unanticipated layer of planning to all changes and discussions. 
  • My campus uses Moodle which has built-in integrations with Collaborate Ultra. There seem to be two paradigms emerging: 
    • Use Collaborate Ultra and teach synchronously with recordings made available.
    • Make videos for asynchronous learning and then use Collaborate Ultra for office hours. 
  • I’ve chosen to go with asynchronous videos and then use Collaborate Ultra for office hours because I’m already comfortable with making videos. For colleagues with less experience teaching online at my institution, the synchronous approach with recordings seems to feel more accessible from what I’ve been seeing in emails.
  • I make videos using OBS Studio and upload them to YouTube. It is very easy to embed them into Moodle – just drop in a link. Students are familiar with YouTube, and the process is basically painless. (If I need to edit videos, I use OpenShot Video Editor, but with the amount of videos I’m making I’m just going for quick right now.)
  • If I’m making a video of anything other than PowerPoint, I use PenAttention to highlight my cursor. Remember to zoom in on text and applications (e.g. I normally use a small font in RStudio but enlarge it for videos).
  • All of my YouTube videos are unlisted (anyone can watch, but only with a link). I don’t have a good reason for this instead of making them all public. I make a playlist for each class that I add every germane video to; I share this playlist link with the class often.
  • Some students have logged into my office hours expecting content delivery – establishing norms for virtual office hours seems to be something I need to proactively do. 
  • In changing to online, we’ve also changed our grading schemes. We decided to use two different weighting systems (with students earning the higher grade) because of all the uncertainty surrounding this transition and the lost opportunities for improving grades by doing well on a heavily-weighted final.
  • For many of my students, this is their first online class. Explaining the different options for submitting assignments needs to be explicit. I find myself intentionally repeating the same information in multiple messages and on different platforms (email and Moodle).
  • I’m also teaching an introductory, calculus-based probability course this semester. Many of the students are not math or stats majors and don’t know LaTeX. Being very flexible in terms of how assignments are submitted is key – I’m fully expecting some students to email me photos of their homework, and I’m okay with that. 
  • I’ve decided to try to use Zulip with my probability course (about 20 students). This is similar to the Discord app that Chris Engledowel talks about in his StatTLC post, but also includes the ability to use LaTeX, syntax highlighting for code, and is open source. Lots of pros, but the cons is that it is less familiar to students than Discord. So far about ¼ of the class has signed up, but there has been very little use so far (only been a day or so). Students seem to be using it mostly for private messaging me rather than for interacting with each other.
  • We were supposed to have a project at the end of the probability course. This is still happening, but recognizing that I will be less able to support some students, I have developed a few “canned projects” for students to do that are essentially some readings and problems on new topics. (I would offer the same thing in a statistics class with a few pre-selected datasets rather than having students find their own data.) I am still encouraging students to pursue a more creative project, but I recognize that that is not likely to happen for everyone this semester.
  • This blog post has been circulating among my colleagues and raises some really interesting points. Since reading it, I’ve resisted calls to poll students about their technology availability (e.g. webcams, scanners, printers, etc.) because a) this was never an expectation for the course and b) I know some don’t have them and I will already have to accommodate that. I’m trying to meet students where they are and be even more flexible than usual right now.

Laura’s (Z.) Situation

Classes: Introductory Statistics course (6 sections with about 60 students each, course coordinator), Advanced Regression course (about 28 students, half upper-level undergrad stat majors/half MS non-stat majors)

Switched to: online classes (asynchronous and synchronous)

Technology: (Introductory Statistics course: StatKey and JMP, Advanced Regression course: R)

Laura’s Thoughts

I am currently teaching 2 courses; an introductory statistics course and an advanced regression course. The student audience for these courses are very different, and therefore will teach them online differently. I have been reading an overwhelming amount of tips for teaching online, and I am sharing what I have decided will be my best approach to teaching “online in a hurry.”

These are my recommendations for any course, which I will use for both of my courses:

  • Keep it simple, not just for the students’ benefit, but for your sanity as well.
  • Make videos to share with students.
    • Videos should be short for two reasons. First, students will lose interest if they are too long. Second, if you make a mistake, you won’t have to redo as much.
    • Videos should be imperfect. No matter how much of a perfectionist you are, you need to focus on the bigger picture. Don’t worry about having perfect sound quality, saying “um” too much, or having your kids or cat run into the room. Just get it done and out there for students.
  • Try to keep things as similar to what we would do in class with the possible exception of being asynchronous. Students are stressed and if we can keep things similar to what they knew before, that may help relieve stress.
  • Send a detailed weekly checklist to students with recommended dates on when to have videos watched, upcoming due dates, etc…
  • Avoid sending too many emails. We are getting a lot of emails, so we should expect students are also getting a lot of emails. Try not to overwhelm them. Try to write one email per week, ideally on Mondays, providing an overview of what is to come with the checklist that is kind, empathetic, and encouraging.
  • Don’t forget about your TA’s, they are nervous too! Have weekly online meetings with them to ask them how they are doing. Give them the opportunity to ask questions not just about the course but also about life in general.

For a large introductory statistics course, I have additional recommendations. For some background information, the introductory statistics course I work with has 6 sections, each with approximately 60 students. I am the coordinator for the course, and therefore have been in charge of getting it ready to be online.

  • Teach asynchronous with videos. Students are across the country, in different time zones, with different access to internet.
  • Provide software output on assignments in case students do not have access to software.

For my advanced regression course, I have 28 students. Approximately half are upper-level undergraduate students and the other half are Masters-level, non-statistics students.

  • Have spent a lot of time talking to myself creating the online videos for my introductory statistics students and am missing the live aspect of teaching. I am planning to do synchronous teaching for students who want to attend. I will record the lecture during that time and will post it for students who choose not to attend. This is going against most of the recommendations I have seen, but I am going to give it a go anyways!

My plans are not perfect, and will likely change after the first week of online teaching, but that is OK! Be honest with your students and they will appreciate the effort you go through to help them through this challenging time.