March 2020
Notes on a Zoom Class (14 March 2020)

Notes on a Zoom Class

14 March 2020

On Friday, I taught my first class using Zoom. It was an interesting experience, and I’m wondering what, if anything, I should change for next class. (About two years ago, I had conducted a class using Zoom, and I’ve been in many Zoom meetings, but this was rather different.)

I’m currently teaching Computer Security II. It’s a rather small lecture class, with 22 (nominally) in-class students. This was the third day of Zoom-only classes at Columbia, so almost all of the students had established their own Zoom routines by that point. I requested that students turn on their video, because I try to look around the room for feedback if something is unclear—but essentially no one complied.

I had a few technical hiccups. I’d intended to run the class from an iPad Pro, but I’d forgotten that I’d need a USB-C to 3.5 mm jack adapter. Instead—and rather to my concern—I had to do a quick install of the MacOS Zoom package. I also ran into a UI issue trying to do proper screensharing on the iPad—if you want to, e.g., show slides of some sort, you have to start that, switch to Zoom, start sharing your screen, and then switch back to the slide app. Furthermore, there’s a permission pop-up about Zoom wanting to record your screen—that’s not what it’s doing, but that’s the interface that it uses. You then have to tell the permission box that you want to record the screen (on the second pass, you say to authorize Zoom, I think) I’d tried the more obvious route: trying to open a Dropbox or iCloud file within Zoom. That sort-of works, but not well. (Btw: the official advice here is to use PDF slides and not Powerpoint; apparently, Zoom doesn’t like Powerpoint as much. I’m not sure why not.) There was also some screen-sharing glitch at the start that required me to exit and restart the application.

It goes without saying that you should use earphones/earbuds when doing any sort of teleconference.

In an informal test on my own, I found a problem when two different screens had different aspect ratios—it matched the height, meaning that if I shared the screen that was longer relative to its height, I had to scroll left and right on the shorter screen. When I shared in the opposite direction, there were black bars on either side of the longer screen, but that’s exactly what I’d want. So: make up your sides in, say, 4:3 or 11:8.5 format, rather than 16:9.

I strongly recommend using two screens, one for slides or video of yourself, and one to see the panels with the participant and chat panels. Using my Mac laptop, I could keep the slides on my external monitor; the laptop’s screen showed the “gallery” view of logged in students. I used an iPad for the participant list and chat window, and glanced at it on occasion. I may try switching those roles next time, to have more room for the student gallery—but again, that doesn’t help much with no student video. And if I use my laptop to project, I’ll have to move my external camera/mic or use the laptop’s built-in camera.

The biggest problem I had was lack of visual feedback. I’ve recorded lectures in empty classrooms before; it’s never gone pleasantly. In fact, in the past when I’ve had to prerecord a lecture because I’d be traveling, I’ve invited any students who were available to attend the recording session. A few would always take me up on the offer; that helped a lot. Perhaps, if the Zoom gallery view showed more students—even with a small class, it didn’t show everyone—it would have been better, but again, essentially no one was willing to have their video on. (I can’t say that they’re wrong to value their privacy. In that class two years ago, one student forgot she was on video and changed her top during class.)

It would be interesting to try to teach a seminar class this way. I would insist on video for that. (I’ll be attending a Zoom class Wednesday night; I’m curious how it will be conducted.) I normally do stop to ask questions of the class when lecturing; there were no instances where I wanted to yesterday, but next lecture will have some opportunities. I wonder how that will go.

I asked the class for feedback on whether I should run the next class differently. For a number of reasons, I always use slides when lecturing, but since I really want the visual feedback (if I can get the students to turn their cameras on…), I suggested that they download my slides in advance while I simply lectured on video. None of the students who responded liked that idea; they all wanted my slides projected.

I should note: even though I unmuted everyone for the discussion, almost no one was willing to respond verbally; they all preferred to type using the chat function. I do suggest, if feasible (it isn’t for me), that a TA monitor the chat room continously, so that the instructor doesn’t have to glance over constantly.

There have been some privacy concerns expressed about Zoom. I’m still assessing those and may do another blog post later. For now, I’ll opine that instructors should make sure that “attendee attention tracking” is disabled. (To be fair, as anyone who has ever taught knows, it’s really obvious which students are not paying attention. This merely replicates that…) Also, some of the concerns in that article are about Zoom’s “webinars”. My class is a “meeting”; Zoom treats them differently.

Finally: I did have fun with Zoom’s virtual backgrounds. For the first half of the class, I appeared to be in Grand Teton National Park; for the second, I downloaded a picture of Saturn from a NASA website… I think I’ll look at my own photo collection for some more interesting landscapes. I know I have good pictures of Mount Rainier, the hoodoos in Bryce National Park, and more. Or maybe I’ll just appear in front of the Pillars of Creation or a spiral galaxy

I have the following recommendations:

Here is my set of blog posts on Zoom and Zoom security.

  1. Notes on a Zoom Class
  2. Zoom Security: The Good, the Bad, and the Business Model
  3. Zoom Cryptography and Authentication Problems
  4. Trusting Zoom?
  5. Is Zoom’s Server Security Just as Vulnerable as the Client Side?
Tags: Zoom