Speak your science: How to give a better conference talk, Part 2

Part 1 — Part 2 — Part 3

Today, we have the second of three cross-posts by Emily Lakdawalla, the Senior Editor of The Planetary Society, on giving talks about your research. Emily is an internationally admired science communicator and educator. She holds a Masters degree in planetary geology from Brown University, and will release her first book this year.

You can find Emily’s original post from The Planetary Society here.

Figure 1. Søren Meibom, Courtney Dressing, and Laura Schaefer (then all at Harvard) addressing the media at a press conference talk at the 225th AAS Meeting in Seattle, WA. Credit: AAS/Joson Images

Note: If you didn’t read the previous post on what to do before starting your PowerPoint, go back and read that part first!

What visuals will serve to amplify your story?

I’ve observed that a lot of people use the phrase “prepare a talk” as though it is synonymous with “compose a PowerPoint presentation.” Don’t do that. The purpose of slides is to emphasize or amplify points that you, the speaker, are making with your voice and your body language. No matter what, your slides should serve to enhance your presentation, not to distract from it.

In fact, you should be capable of delivering your entire talk without any slides at all, because I promise you it will happen sooner or later that an A/V disaster will require you to. (I once gave a half-hour talk about amazing solar system photos without being able to show a single photo.)

The number one error that almost everyone makes with PowerPoint presentations: There are too many words on your slides. People do this as insurance against forgetting their words, but it is bad for a conference presentation.

We use the same parts of our brains to process spoken language and written language. If you show me a slide containing more than a few words, I must choose between reading your slides and listening to you speak. I am physically incapable of doing both at the same time. Instead, I jump between reading some text and listening to some speech and then I miss things and I get lost. If your entire talk is written out on your slides, why the heck are you even talking to me? I read faster than I hear. You could just stand up there silently and advance your slides periodically. Instead, of course, what you do is turn your back to the audience in order to read your slides aloud, which is, again, an act of disrespect, even if you don’t intend it as such.

(Some speakers compound this evil of reading their entire talk aloud from their slides by using a laser pointer like the bouncing dot on karaoke lyrics, zapping each word as they read it.)

When I first wrote this article five years ago, I strongly advocated putting no words on slides. I still advocate that position for public talks. But commenters made several good points about why some words are useful, so I’ve adjusted my advice. Titles on slides are valuable as signposts through talks, especially for people who don’t share your language. Writing out jargon or otherwise unfamiliar words helps you teach those words to your audience. In every case, though, the text on the slide should serve to emphasize or underline the points you make with your speech. They should enhance or clarify, not distract from, the words issuing from your mouth.

One advantage of having few words on slides is that if you find you have misjudged the pacing of your talk, it’s not obvious to your audience when you are skipping material or slowing down in order to return to the right pace!

Graphs are a challenge in talks. Used well, they can make a scientific point clearly and succinctly. Used poorly, they can be a distraction. Graphs that are good for scientific papers are typically lousy for talks. It’s not just a matter of font size and color. Good paper graphs have high information density, so throwing a fully developed graph on a slide is worse than presenting your audience with a paragraph of text. Instead, I advocate building a graph as you speak — draw the axes first, mention their extents, add your data (one data source at a time, if there are multiple ones, naming each), and then any trendlines, and so on. It takes time but if you don’t have time to explain a graph, then don’t put the graph in your talk.

Sometimes you don’t need a visual to emphasize a point. In those cases, consider not having one. Put up a blank slide and watch the entire audience suddenly make eye contact with you. I like to put blank slides in places where I am making transitions in talks. It is a reminder to me to remind the audience where we came from, and inform them where we are going. I can look them in the eye and check in with them to see if they are still with me, and let them know that the story is about to shift.

Your final slide is a special slide. It may be the one that the audience sees the longest. Do not have a slide that says only “Questions?” Instead, put your Tweet-length conclusion on it. Write your name and some kind of contact information on it for the benefit of people who want to discuss your work with you (email, Twitter, etc.) And then thank the audience for the gift of their attention, and invite them to ask questions.

Try to anticipate the questions your audience will have about your talk. You might have some backup slides prepared after your conclusion slide. This is a good place for the graph from your paper, or to paste in some text on your methods, because they may be useful tools in your response to a persnickety question. With a little luck, you can look like a genius for having just the right backup slide in your deck. If no one asks a question, one of these slides can serve as an opportunity to say just a little bit more about your work, or to advertise your collaborators’ presentations.

Preparing to give your talk

Practice. I’m not just talking about practicing the specific talk. I mean: practice speaking about your science. Talk to your coworkers, your friends, your roommates, your family, your hairstylist, your cab driver. My plumber loves visiting my house because he loves to talk with me about space. Take advantage of any opportunity to speak to people about science. Practice is important because speaking is a different skill from writing.

Regardless of who is in your audience, you must use less jargon in a spoken talk than in a written paper. In a paper, if I come across a term whose meaning I don’t recall, I can look it up. In a talk, I can’t do that. The words you speak may not be as precise, but more people will understand your meaning, and remember, that’s the goal.

Relatedly: Simplify your sentences. In a technical paper, a single sentence can span a whole paragraph. It’s a way to armor sentences against criticism. But in speech, if I lose track of which statement your lengthy list of clauses is modifying, I lose the whole sentence. Complete a thought before moving to the next. Avoid passive voice. Give your sentences clear subjects, verbs, and objects. If a point is important, repeat it. Repetition is like verbal underlining.

Whatever you do, don’t call this “dumbing down” your language. Language is a tool for the communication of information, and “dumb” is a slur levied against people who cannot speak. If you have failed to convey the information you intended, you are the one who is having difficulty speaking well!

If you tend to talk fast when you are nervous, then practice, really work, on speaking more slowly and carefully, enunciating your words. Don’t be afraid of silences — you don’t need to fill every moment with sound.

When you get to the front of the room, take a few seconds to consult your notes and frame your first sentence. Make sure you understand how to advance your slides. When you’re ready, look out at the audience, and smile. What kind of smile depends on the circumstances. It could be an “aren’t we all having fun?” smile. It could be gritting your teeth in determination. Whatever you need. Take a deep breath and release it. Then inhale again and speak that first sentence.

Thank you for reading

Remember: Respect your audience. Employ words they’ll understand and provide context they require to enjoy the story you have to tell.

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1 Comment

  1. About text on slides, I really like the “compromise” of writing the point of the slide as the title of the slide, and having that (usually) be the only text. (So instead of writing “Results”, write a sentence stating the result.) It is a clear pointer/reminder to the audience about where we are at any given point, it avoids cluttering the slides with unnecessary text, and it’s a great exercise when planning and structuring the talk.

    Points regarding plots are great — I will add one more piece of advice: think about how you would explain a plot/diagram if you were using a whiteboard. Maybe circling/annotating some parts, adding arrows, drawing a line to illustrate a trend, etc… The same can be done on a powerpoint and is much more effective than a bullet point list of text next to the plot!


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