3 March 2010

Advice for giving a talk

Posted by Callan

What makes a good presentation?

I watch a lot of talks. Between monthly meeting of the Geological Society of Washington and professional meetings and student presentations and local departmental seminars, I see a lot of people present information aloud, with varying degrees of success.

I also give talks. While I don’t claim to be the best presenter in the world, I do know a good talk from a bad talk. I try to keep mine on the “good talk” side of the spectrum. Giving a talk, whether at a professional meeting, in a board room, or as just another day in class, is an act which is as much theater as it is information delivery. I’ve never taken a public speaking class, but I’ve got some real-world experience. Today, I’ve got some advice for anyone who’s going to be giving a talk. I’ll assume a traditional modern talk: a single expert speaker talking for half an hour or less, backed up by a PowerPoint slideshow. (“Expert” here means that you know something the audience doesn’t know. If that’s not the case, you might ask why the hell you’re bothering to give a talk in the first place.)

I hope the second-person style of this advice (“you, you you”) isn’t offensive to readers. Just imagine it’s an “open letter” to someone else, someone who you and I have just seen give a crummy talk.

Know what you’re talking about enough that you can speak extemporaneously. Reading from notes or an outline means that you (the speaker) are engaging with a piece of paper (or a laptop), and not with the audience. No notecards. You can use the images on your PowerPoint to guide your thoughts, but you should know the material, and the ‘trajectory’ of what you want to say, well enough that you don’t need some sophomoric crutch.

It should go without saying that one way to achieve enough confidence to speak extemporaneously is to practice: tell people at cocktail parties what you do, what topics you’re researching. Practice in front of the mirror. Practice in front of your spouse, your nephews, your pets. Practice with your peers, your professors, your students. Develop a full, robust taste for your presentation’s content that is independent of a particular string of words.

Look at people. Look your audience members in the eye, moving from person to person every few seconds. Do not talk to your PowerPoint up there on the screen. (Jess noted this in a similar talk advice post last September.)

Move around. The dynamics of a mobile speaker are much more engaging than a sessile speaker rooted behind some podium. I mean both waving your hands about, and physically walking around the room, forward and backward, left and right. Get close to people: like a magnetic field, human proximity is effective at making connections.

Use evocative language, including analogies, humor, precise vocabulary, pithy quotations, and the like. The spoken word is your medium, PowerPoint is your visual aide, and your expertise is your subject. Because you are delivering your explanations via the spoken word, you should use your words to sculpt a rich landscape for your listeners. Use active verbs like “wiggle,” “pierce,” “slam,” “jet,” “snap,” “rub,” and anything with a violent or sexual connotation. People pay attention to sex and violence; you can use these words as lures to draw them in to your subject matter. Also, vary the pitch of your voice. Anyone speaking in monotone clearly doesn’t care enough about their subject to get excited about it. The message to the audience is that they shouldn’t care either.

If you’re a ham like I am, then act it out. If you’re describing rocks getting squished, mime out being in a trash compactor. If you’re describing a cobble bounding downstream, jog a little slalom course across the room. If you’re talking about the position of dinosaur legs beneath their body (as opposed to say a crocodilian, where they stick out to the side), slump down on your belly and show what you’re talking about by contorting your own limbs in different positions relative to your body. Not everyone is comfortable with physical acting; some consider it demeaning to the dignity of the speaker, especially in staid, professional crowds. If so, that’s cool. But the audiences I have observed eat it up, professionals or not. It’s engaging and endearing.

It is okay to pause in silence while you gather your thoughts. Avoid nervously filling this pause with an “Umm” or an “Err.” Not only only are umms and errs 100% information-free, they ruin what could otherwise be interpreted as a dramatic pause, full of conscious intent. Good songs are not just a constant stream of words, they include slow bits and wordless bits and instrumental bits, all of which give the listener a chance to cogitate on their meaning. You’ll notice on “All Things Considered” or “Radio Lab” or “This American Life,” the producers insert little “buttons” of music, about 10 seconds long, in between information-rich pieces. Good presentations should be like that too, but unlike radio, you don’t have to worry about “dead time.” Your audience can see you, see your PowerPoint. They know you haven’t gone “off the air.” Better still, your pause gives people a chance to swallow your thoughts. Ramming information down their throats without a chance to chew it will not nourish them with your ideas.

Now for some specific advice about putting together a decent PowerPoint (or Keynote, or whatever) slideshow:

Use as few slides as possible to get your point across. Everyone is busy, and we don’t want our time wasted. Get to the point, and make it worth our time to be sitting there in your audience.

“Outline slides” are those that present your talk as an outline. (“First I’m going to give you some background on the problem, then I’m going to tell you about our research approach, then I’m going to interpret our results in terms of the dominant paradigm.”) In my opinion, outline slides are a waste of time. Clearly, any effective presentation is going to supply necessary background, describe what is unique about the presenter’s approach, and conclude by tying it back into the big picture. You don’t need to waste our time by outlining it for us. No decent movie or television show (including those about science), starts off with an outline! A shared outline is redundant to a well-constructed talk. If you’re a unsophisticated enough presenter that the only hope of communicating your intent is to repeat it via outline, then you shouldn’t be talking. Shut up and go back to your office; write it all down as a paper instead.

Use as few written words as possible. PowerPoint should be used as a slide projector: It is not an outline (or worse, a transcript) of what you intend to say. The worst presenters type out what they want to say, then read it aloud off the screen. This is an abomination of presentation. It is the antithesis of engaging your audience with your expertise. Ideally, all your slides should be imagery. There should be no slides of just text.

Use pictures. Use photographs. Use cartoons. Use graphs. Use data tables. Show movies. Show animations. Use visualizations. PowerPoint is a visual medium: use it for what it’s good for. Use it as a slide projector.

No sound effects, no fancy slide transitions, none of that stuff (“phluff,” as Edward Tufte called it). …Good lord, do I really even have to say that? Unfortunately, I think I do. I have observed people (students and bureaucrats, mainly) sometimes use these “bells and whistles” with what I suspect is an intent to distract the audience from a lack of content. Use of these features is an insult to your audience. No “clip art” either.

Use images at sizes at or below their inherent resolution. (i.e., not at sizes above their resolution.) In other words, if you find an image online that is good for your talk that measures 200 x 300 pixels, do not blow it up to 800 x 1200 pixels. It’s going to look horrible if you do that: pixelated and grainy and incredibly bad. I have seen some of the scientists I respect most give talks with these sorts of graphics — it looks like something a sixth grader might have thrown together. I find it shocking that someone so skilled in one aspect of their professional life could be so completely clueless in another. Even if you’re not capable of generating your own graphics, have a little bit of aesthetic sophistication.

Number your slides. If your presentation has 20 slides, your first one should have “1/20″ tucked down in a lower corner, somewhere unobtrusive but obvious to anyone who’s wondering how much longer you’re going to go on. The second slide should say “2/20,” and so on. This gives your audience an orientation to your intended talk length, and they can then decide whether they want to keep sitting there, or whether their time would be better spent off getting a cup of coffee. One of the first things that I always do when I am watching someone set up for a talk is to steal a quick glance at their total number of slides. If they’re going to attempt to get through 55 slides in 20 minutes, then I know that either (a) they’re going to be going too fast for me to absorb the slides, or (b) they’re not going to be finished on time. A general rule of thumb is one slide per minute, though that’s flexible depending on your content and speaking style. Notice that numbering your slides does not do any good if you don’t say out of how many total that number is. In other words, seeing a “6″ at the bottom of your sixth slide doesn’t help me estimate when you’re going to be done with your talk. (“Is that 6 out of 7? Or 6 out of ∞?”) Not that I’m not interested in what you have to say — but it’s unlikely I’m going to be rapt by your talk, smart as you are. My brain is going to be thinking about other stuff at the same time. Work with me here! Give me a sense of your plan for the next 20 minutes of my life.

End it cleanly, decisively, and preferably a little bit on the early side. Let us know that you’re done without saying, “Umm, …and that’s the end.” Think about the end to the most satisfying entertainment you’ve absorbed lately: a film, a song, the latest episode of LOST. You know it’s over without them having to spell it out by saying “…and that’s the end of this movie.” Asking what questions your audience has is a good fall-back ending statement, if you can’t think of anything more clever. Notice I don’t say “Are there any questions?” I say “What questions do you have?” Your expectation should be that your opus generates insightful, chewy interrogatives from those privileged enough to hear it. Clearly, any talk worth spending the time listening to should generate some thinking, some feedback. If it doesn’t, that’s a major red flag that you haven’t engaged your audience with your material.

OK: I’ve given all my advice to our nameless third-person lousy speaker. What else would you tell them? Chime in via the comments section below.