Many of us are preparing to virtualize our classes in response to the COVID-19 outbreak that is spreading in the United States. I wanted to share my experiences teaching my Introduction to Robotics class with video lectures last semester. My motivation for doing online lectures last fall had nothing to do with the COVID-19 outbreak. First, I felt that the time I spent preparing for lecture each class had to be spent again each year. Although I reused slides, I still needed to refresh myself on the slides before each lecture and prepare mentally for what I was going to say and when I was going to say it. Second, it seemed that blasting out a lecture at a group of students who are mostly passively was not the best way to use my face time with students. I would of course ask the group questions, and mix in pair-wise exercises where the students talk with a partner. However most of the time was me blasting technical material at them, and I wanted more informal small group interactions in the class period. Third, as we expand our drone program, it seemed useful to expand access to the lecture materials beyond the students who are on Brown’s campus.
My starting point was a curriculum, syllabus, and set of lecture slides that I developed for the course over the past two years. I previously helped out a bit with the Udacity Flying Car Nanondegree, and one of the key lessons from that experience was to focus on small blocks of content. Based on the Sheriden center’s advice, I started out each lecture by defining learning objectives. The verbs in this page were a helpful starting point. I decided to use the edge.edx.org platform to host the online lecture content because they take care of the hosting and it has a framework for hosting videos as well as asking auto-graded questions, and Youtube to host the videos themselves. Defining learning objectives already put a lot more structure into my slides than I had before. (Yes I know I should have been doing this all along!)
Next I divided each slide deck into small chunks that I could cover in two minutes or less. The lectures I created consisted of a short two minute video followed by a few multiple choice questions. A crucial benefit of the online modality is the ability to ask every student questions after each block. Each question can be automatically graded, allowing students to get immediate feedback on what they understand and don’t understand. At first I worried that I wouldn’t be able to ask substantive questions, and it is true the format does not lend itself to extended discussions. However a large lecture itself is hard to have substantive discussions; when it happens, it’s often a few people talking and most people passively listening. Instead I tried to ask multiple choice questions that were tied to the learning objectives for each section.
We experimented with more sophisticated types of questions, such as creating a drag-and-drop question for the different blocks of a PID controller, but ultimately stuck with multiple choice questions. More complicated questions ended up being more work for incremental benefit. We also considered having coding questions for example in some kind of Jupyter notebook. However we ultimately decided that the best way to assess coding was to use our existing projects and assignments, where students program on their own drone, on their own time through structured assignments and projects. This simplified the creation of online lectures since they only needed to assess content knowledge rather than the ability to write programs or derive equations.
I used a screen capture program to record myself talking over the slides. If I made a mistake, I stopped recording and restarted from the beginning. Since each planned video was only two minutes, this process was easier and faster than editing videos later. Merely the act of recording improved things because I would find bugs in my slides, stop and fix them, and then record a clean version. The ability to stop and rerecord when something came out wrong meant that the version the students eventually saw was easier to understand, and more information-dense. As a result I was able to cover the material I wanted to cover in each lecture in far fewer minutes of recorded content than the 80 minutes I had planned for lecture.
Once I had a process set up it took me two to three hours to record content for the 80 minute lecture from my previously existing slides. The first block of time I would use to define learning objectives (which I probably should have been doing before, but wasn’t), as well as create questions. The second block of time I used to record. I then uploaded the videos to Youtube. I used the built-in editing tool to crop the beginning and the end when I was starting and stopping the screen grabber. Then I put them in EdX and entered the questions after each video.
During class, students could choose to build their drone, work on assignments, or watch the lectures. Students would do some of each. I used the class time to answer individual questions, help students debug their drones, and perform checkoffs. I felt that I got to know the individual students better with this in-class style than when I lectured to them, and they got more individual interactions from me. Effectively I used the class time as extended office hours. Of course this sort of interaction is hard to make happen now, remotely, but hopefully this experience will help those who are transitioning their classes online!