The job talk is a performance
This is the second in a series of posts with advice for computer science academic job candidates.
One shot, one opportunity
The philosopher Marshall Mathers once asked rhetorically, “Look, if you had one shot, or one opportunity / To seize everything you ever wanted in one moment / Would you capture it or just let it slip?”
He added, “Yo.” 
I don’t mean to imply that an academic position is everything you ever wanted, but it’s a pretty good life (although not for these reasons). Like it or not, it’s set up so that your career up until this point comes down to one moment. After years of hard work, your ability as a researcher will be judged primarily based on how you sell yourself in the fleeting span of an hour. Of course, you’ll (hopefully) give your talk at many places, but it’s going to be the same talk!
There’s a reason I’m saying this, and it’s not to stress you out even more. Rather, if at any point the level of preparedness that I suggest seems excessive or disproportionate, remember the wise words quoted above.
Public speaking is a performance
My first piece of advice is to read the book Confessions of a Public Speaker. As in, don’t even think about giving your job talk without having read it. You can read it in a sitting; putting it into practice will of course take longer. I cannot overstate the impact this book had on my talk (and my public speaking in general). There are probably other books that capture much of the wisdom in Confessions, and I’d love to hear other recommendations, but if you’re going to read one book it would have to be this one.
There are numerous very useful little details in the book, but it has one central idea that can be boiled down to the phrase “public speaking is a performance.” Job talks are are even more of a performance than public speaking in general, since the audience is specifically there to judge you. This is a generative metaphor — it allows you predict things about your job talk based on what you know about performing. Fully appreciating the metaphor will require reading the book, but here are two such predictions that might otherwise be surprising.
Your first priority is to entertain
Certainly you must both entertain and inform, but the point is that you don’t really have a shot at the latter if you fail at the former. Sitting in a lecture, as everyone who remembers their student days is surely aware, can be excruciating; it’s an extremely unnatural situation from an evolutionary perspective (again, read Confessions to appreciate why.) The chart below from the book What’s the Use of Lectures? shows students’ heart rate over time as they sat in a lecture. It’s only a drop of a few beats per minute, but it translates to an enormous difference in alertness.If you don’t do anything different in your talk and simply present your material, your audience’s attention level will be greatly diminished by the half-hour mark, and by the end of your talk people will basically be comatose. Anything you can do to break the routine, linear, hyper-boring pattern of a lecture will help jolt the audience out of their stupor. (That includes asking questions — I usually asked two or three in my talk.) Otherwise they won’t be excited about you nor remember much after the talk.
Rehearse, rehearse, rehearse
You may have heard “practice, practice, practice.” I’d rather cast it in the language of performance, as there are some subtle differences. For example, when people tell you to practice, they tell you not to overdo it because you’d lose your spontaneity. I disagree. In a rehearsal, everything is practiced down to the last detail. In fact, the apparently spontaneous things that I said my talk were the most well-rehearsed parts.
Rehearsal should include videotaping yourself and watching it. Yes, it’s painful and majorly cringe-inducing, but it’s absolutely, absolutely essential. In addition to all the obvious facets of good presentation style that I won’t repeat, one of the subtle but important things you should watch for is nervous tics or other repetitive behaviors — almost everyone has one or more of those, and they can almost derail your talk by distracting your audience.
The reason rehearsal makes such a huge difference is that when you’re delivering a rehearsed talk, your every word and gesture is subconscious, freeing up your mental bandwidth for observing and reacting in real-time to the facial expressions of your audience. There are never more than 40-50 people in these talks, a small enough number that you can instantly notice if someone looks confused, skeptical, or bored. But this won’t be possible if you have to think through your slides instead. The reduction in cognitive load also minimizes the chance of “hitting the wall,” a phenomenon of sudden mental fatigue that’s a serious danger in long-ish talks and can leave you helpless.
Let me close with an example of a little theatrical thing I did that shows the value of rehearsal and the performance metaphor. One of the goals in my location privacy project is to minimize smartphone power consumption. When I got to that part, I’d say, “those of you with Android phones know how bad the battery life is. In fact I usually carry a spare battery around… actually, I think I have it on me.” Then I’d pull a smartphone battery out of my jacket pocket with a bit of a dramatic touch. Somehow the use of a physical prop seemed to reframe their thinking from “yet another academic paper” to “solving a real problem.” It would also usually elicit a laugh and elevate their attention level.
There is so much more to say about job talks, not to mention other aspects of the job interview. I might do follow up posts on a mathematical model of audience behavior and/or an explanation of why slide transitions are (by far) the most important part of your slides.
 This post was written while listening to Lose Yourself in a loop.
 If it needs to be said, I have no stake in the book, financial or otherwise.
 I hasten to add that teaching is very different from public speaking and is emphatically not a performance.