Quarter Million

My YouTube channel on OCaml reached one quarter million views in July. It’s maybe the most high impact work I’ve done in my whole life. The college wrote an article about it. Here’s the rest of the story.

In summer 2020, as I was planning for the fall offering of CS 3110, I was teaching a summer class (the inaugural offering of CSmore) remotely — out of necessity, of course, because vaccines weren’t yet a thing. I lectured over Zoom from my home office. I hated it. I also knew that the fall class would have to be by Zoom, because there was no way to fit a class of 400 students into a socially-distanced lecture hall.

One day, while listening to Ariana Grande’s Bad Idea,* I had just such an idea. The university had offered that instead of teaching synchronously by Zoom, I could teach asynchronously by recording lectures. My bad idea is that I would record them as the kind of short, focused, carefully edited videos that one finds in better-taught MOOCs. Dan Grossman’s excellent PL MOOC was a primary inspiration.

Q: Why was this a bad idea?

A: The effort required.

But it’s not like I was doing anything else during that time. I was in the privileged position of not having to home school any children, or take care of ill family, or really do anything else except stay home 24/7 and devote a semester to recording videos. And so I did.

I built a green screen recording studio in my basement. It cost between $2,000–$3,000 and a couple of weeks of work to identify, purchase, and install equipment. One of those weeks was mostly spent watching YouTube videos about how to make YouTube videos. How meta.

For that fall semester, I lived a cloistered life. Each Thursday I would suit up,** head down to the basement, and record videos the whole day. Usually I skipped lunch and recorded straight from 9 am to 3 pm. That would get me enough raw footage for a week’s worth of lecture videos.

I was surprised to discover that all the stage-fright nerves of being in front of a live lecture hall also existed when it was just me in the basement. The first Thursday I recorded, I broke out in an ugly red pimple on my chin. It visibly grows in size throughout the day’s videos. After that, I asked my wife for concealer make-up, and wore it for future recording sessions.

Recording was just the first step. Editing took place on Friday and Saturday, and sometimes Sunday, too, depending on how many mistakes I’d made during the initial recording session. I did the editing in ScreenFlow, which I highly recommend for this purpose. It was exhausting listening to my own voice that much. Actually, it was just exhausting, period. Some weeks as I sat back down to keep editing at 11 pm on Saturday, I would cry. Probably a combination of mental fatigue and eye strain. After the editing came the uploading into the university’s LMS, which itself was time-consuming for dumb reasons.

Zoom U was horrible, but, my students in Fall 2020 loved these videos in comparison. To my delight, they let me know that. They also forgave my production mistakes. When I re-aired the videos in Spring 2021, the students were a little less forgiving. They rightly criticized the audio mix quality. So in summer 2021 I re-edited every video to fix some of the audio issues.

Of the about 250 videos I had created during Fall 2020 and Spring 2021, about 200 were suitable for sharing with the world. So I uploaded them into YouTube and embedded them in my online textbook. About a year later, the channel hit a quarter million views. Viewers were coming from every continent (except Antarctica). They were students at other universities, self-learners, even other faculty.

By the end, for every minute of video that ended up on YouTube, I estimate I spent about 20 minutes creating it. I now have an appreciation for the work behind TV and movies.

Teaching at Cornell gives me the opportunity to impact around 1000 students per year. I teach them to write correct, efficient, and beautiful computer programs. I also try to teach them some of my own values about what is important in programming and in life. I even make them read books! They don’t always appreciate that.

Teaching at Cornell also gave me the opportunity to launch something new: teaching to the world. I never would have asked for pandemic, and I know it was a horrible time. But for me, something good came out of it. For that, I’m grateful.


* Maybe it wasn’t while listening to that song. But I certainly was singing it to myself as I filled out the university form committing to teaching asynchronously.

** These days, no suits. I even teach in denim jeans on Fridays now. Sic transit gloria mundi.