In March last year, the pandemic dramatically struck close to home when universities across Canada (and probably in many places around the world) abruptly moved from delivering lectures in person to online. The suddenness with which it happened meant there was scant preparation, with huge impact on professors/instructors and students. In general, the move went well -- a testament to everyone working together to make the best of an unfortunate situation.
Come September, little had changed and many universities, including the University of Alberta, conducted most classes online. This continues for the term that is just starting.
I taught a course on Operating Systems twice last year: January-April (Winter 2020) and September-December (Fall 2020). My Winter 2020 term started off in the classroom with me using PowerPoint slides. This was supplemented with numerous interactive exercises that used the classroom whiteboard, as well as a "human animation" example. For Fall 2020, it was PowerPoint over Zoom, with no whiteboard tools. (Yes, there are whiteboard tools for online teaching, but they are a poor match for my needs.)
Having been out of the classroom for more than a decade, in Winter 2020 I was disappointed to see that the trends emerging in the early 2000s had continued. I had seen class attendance slowly decline and students in class become distracted by their laptop and/or cell phone. The number of in-class questions kept dropping as compared to what I remember from the pre-social media days. Few students were willing to speak up in class and answer questions that I posed. In effect, the class was largely a one-way communication: I was a talking head at the front of the room.
I had more fun teaching my Fall 2000 course than I have had in many, many years (118 students).