this is where the magic happens / photo by cheng-han lee

Ingredients for an online lecture: my Udacity teaching experience

I’ve never lectured with a bell before. You see it in the middle of the picture above, just to the right of my hand. When I mess up in my lecture—and I mess up often—I ring the bell. Udacity’s video editors see the characteristic signature of the bell in the audio track and can zip right to it while they’re editing; they save a little time this way. It takes about eight hours for me to record an hour-long unit. As you might imagine, I ring the bell a lot.

I’m teaching CS 344, Introduction to Parallel Programming, as a Udacity course that starts early next year. Tens of thousands of students will see this unit, but while I’m actually giving the lecture, I’m in a dark room, alone. The dark room has two doors placed back-to-back so it’s extra-quiet. The only light comes from two lamps that illuminate the drawing tablet and the iMac that runs the tablet’s screen-capture software. Above the tablet is a fixed video camera that points straight down. I ought to be responsible for starting the camera and the software, but since I lost two hours of footage the first day by recording the wrong piece of the screen, I tend to ask Katy, the video team manager, to do it. Katy never loses footage. Nonetheless I’m constantly checking the status of the software, the amount of space left on the 2 SD cards in the camera, and the focus settings.

The camera sees nothing but the tablet and my hand, and because the screencast software picks up the writing on the tablet, nothing actually matters but my hand. As far as the students in the class know, I could be a robot above the elbow. (My idea of writing “CUDA” and “RÜLZ” on my knuckles was quietly rejected.) It’s a good thing that we recorded some interview footage, a long conversation with me and my fellow instructor David Luebke, and a promo video for the course. It’s the only proof that the instructors live and breathe.

The tablet is frankly amazing. (It’s a Wacom Cintiq. Maybe all tablets are this nice; I’ve never used one before.) It works exactly like you would hope it would, and this particular model not only accepts my penstrokes but also displays them (it’s both a tablet and a display), so it’s perfect for this purpose. My handwriting gets good marks from the video editors, but it’s nothing special; my drawing is frankly horrible; but I am told, and I certainly understand, that my (passable) writing, (awkward) drawing, and (disembodied) hand together humanize the lecture. (We’re also fortunate to have a talented animator for a couple of minutes per unit.)

Sitting in front of the tablet are my notes. They’re printed in a tiny font and I prepare about 8 pages of notes per unit. For each unit, this takes me two days. I write down everything: every sentence I’m going to say, every joke I tell, everything I’m going to draw. I learned this the hard way; all instructors do. David Evans is the VP of Education at Udacity. He’s nominally responsible for training us to teach in this style, for which he’s developed a unique and highly effective training method.

1. Dave asks the instructor to prepare 5–10 minutes of material as a sample and to submit the material to him for review. The instructor dutifully writes a carefully prepared, detailed script and sends it to Dave.

2. Dave makes numerous excellent suggestions on the material, all of which are clearly correct and sensible.

3. The instructor journeys to Palo Alto to record the material.

4. Dave silently sits behind the instructor in the dark room as he/she attempts to teach from the script. The instructor instantly realizes that the detailed script from which he/she is teaching is woefully inadequate, and in fact the words “too much detail” are simply not applicable to this situation. The instructor bashfully admits his/her degree of underpreparation, Dave doesn’t even have to say a word, and the instructor returns home to do the job right.

The simple fact is, it’s just not possible to wing it in such a lecture. For a Udacity lecture, writing down every word and every action is not only desirable but necessary. As a professor lecturing in front of a live class, I wing it all the time. I pace my lectures by my students’ reactions, I ask questions and use answers to gauge how fast I should go, I make up examples on the spot for demonstration purposes. The feedback from the students makes a huge difference in what I present. But with a Udacity lecture, the piece of sound-absorbing foam on the wall is the only entity that’s listening, and unless you’re some sort of minor improv deity, you’re not going to get away with ad libbing anything. My lecture time in the dark room basically goes like this, with steps 1–3 taking roughly the same amount of time:

1. Carefully read my next sentence, thinking about what I’m going to draw/write and how it fits with what I’ve already drawn/written.

2. Carefully draw/write on the tablet accordingly.

3. Speak my next sentence.

4. Repeat for 8 hours.

The final ingredient for the successful lecture is represented by the can of Dr Pepper (chock full of caffeine) and the hand-lettered yellow Post-It above my notes, reading “ENERGY”. (I wrote this.) It’s said that the camera adds 15 pounds. Well, the Udacity camera subtracts 50% of your energy, so it’s up to the instructor to add it back in. There may be no level of energy that’s “too much” in a Udacity lecture; if there is, I haven’t hit it yet, and I’m not exactly lacking in the enthusiasm department, especially when I’m fortified with Dr Pepper (and the coconut M&Ms readily available in the Udacity supply closet).

Giving a lecture like this for the first time must have been an incredible leap of faith. As it is, I trust the Udacity staff, who’ve all done this before, to steer me and my material in the right direction. I know that I’m teaching more students—many, many more students—in this one class than I will at UC Davis in my entire career. I hope they’ll realize that while most of them are learning a new topic for the first time, their instructors too are learning along the way.