"Short scientific talks for dummies"

As readers know, I had to give a rather big talk at a national meeting (big for me, anyway). Fortunately, it went well. In fact, I was inspired to write rare brief followup to my career advice to young scientists (not rare for being a followup but rare for my actually being brief), in which I recommended doing whatever it takes to get good at public speaking. So, without further ado, here are a few words of wisdom for giving 10-15 minute scientific presentations, learned over 15 years of giving these presentations. (As I'm still at the meeting, the very fact that I'm blogging should be an indication that there isn't much to do around here, and for some reason, none of my friends here wanted to do anything tonight--leaving me in the hotel room to write this.) So, here it are some of my tips:
  1. Pace yourself for approximately one slide per minute. This is not a hard-and-fast rule and depends on the content of the slide. If, for example, the slide is a one-liner or just a picture that needs little comment, then you don't need a minute (or even 15 seconds). However, if it's a data-dense, information-dense slide you might need way more than a minute to march through it. However, in general, a good rule of thumb is that it all averages out to around one minute per slide. So, if you have 30 slides for a 12-minute talk, you have a problem.
  2. Be utterly brutal in editing your slides. There should be no more than two figures or five lines of text on a slide. Any slide that is not absolutely essential to telling your story should be eliminated with prejudice.
  3. Don't just read off of your slides. The audience can read them well enough and doesn't need you to do it for them. Use them as a guide? Yes. Read them verbatim? No.
  4. Control yourself and don't speak too fast. If you're afraid of public speaking, or very nervous, there is a natural tendency to talk faster in order to get it over with faster. Avoid this temptation. You don't want to sound rushed or nervous, even if you are nervous and do want to rush. (This was one of the most difficult tendencies I had to overcome; I still do it occasionally--but fortunately not at this talk.)
  5. On the other hand, don't talk too slowly, or you may find yourself coming up against the time clock and risking having your microphone turned off (unless, of course, you are an influential member of the society, in which case you can drone on as long as you want). Either that, or you may put your audience to sleep. What you want to aim for is a nice, natural, conversational pace.
  6. Practice your talk. Practice it at least 5 times, paying special attention to whether or not you can finish it in the time allotted. (It's very difficult to summarize many months--or even a couple of years--of your life's work in 10 minutes.) Practicing it 10 times is better. It's only a 10 minute talk, so you should be able to practice it 10 times in 2-3 hours easily. A lot of practice will assure that you won't freeze or have a brain fart and forget what you wanted to day. It will also make it easier to recover from equipment malfunctions, should they occur, as you will be so familiar with your material that you can continue even without the slides as the AV tech guys scramble to fix the problem.
  7. No jokes. There's almost never time for them in a 10-15 minute talk anyway; every minute spent telling a joke is a minute you can't present your data. (If you're giving a 45-60 minute talk, that's another thing entirely.)
  8. No cutesy slides or cutesy pictures on data slides.
  9. Thank the audience and/or the society hosting the meeting.
  10. Thank your mentors/collaborators, the workers in your lab, etc.
  11. Don't clutch the podium as though you are on a ship in a hurricane
  12. Look at your audience as much as possible. Minimize your looking at the slides or the monitors. At national meetings these days, there is usually a monitor for you to see your slides, and the actual screens are parallel to you, so that you can't see them very well even if you try.
  13. If there's a spotlight on you (as there was on me), it's disconcerting to realize that you can't really see the audience very well at all. In these cases, just look in the direction of the audience and scan over where you think they are.
  14. Avoid the temptation to keep revising at the last minute. Get the slides ready to your satisfaction at least the night before, if not sooner. Fiddling with them too late will only mess you up.
All of these are simply tips I've found useful. I'm sure my readers can provide more if they're so inspired. In fact, I may submit these to Tangled Bank.


  1. In Toastmasters we are always told not to thank the audience. You're the one doing all the work, they should be thanking you.

    Some other tips I've picked up:

    Move around a bit but don't pace.

    Try not to clasp your hands. (I still do this a lot!)

    Use fluid and natural gestures.

    Rehearsing is important, but it's important that the speech doesn't sound rehearsed. Too much rehearsing can make a speech sound stale or stilted.

  2. Toastmasters is incorrect, at least in this specific type of talk, a brief scientific talk presenting data to a medical or scientific meeting.

    At scientific meetings, the speakers have submitted abstracts, and from those abstracts the Program Committee chooses who will speak. It is therefore considered polite (and advisable) to thank the scientific or medical society for letting you present your data.

    As for rehearsing, in a 10-minute scientific talk, it is more important to get it right and done in time than to sound natural. (Obviously it's better if you can do both.) Consequently, I don't think it's possible to over-rehearse this type of talk.

  3. I get my students to read "Dazzle 'Em With Style" by Dr.Robert Anholt, a slim volume that is an invaluable tool for making good scientific oral presentations.

  4. Powerpoint tip #3467: Use a sans serif font like Arial. They're easier to read than serif fonts like Courier or Times.

    One of my favorite things at professional meetings (besides all of the intellectually stimulating research) are the session moderators. Their only job is to quickly introduce speakers and cut people off when they run over their alloted time. It's always fun to see how they deal with the people who run over. Some quietly begin approaching the podium until they are standing right next to the speaker. Others are more aggressive and stand up and say "You're out of time!" A piss poor moderator can allow an entire session to run over and cut into breaks.

    My favorite moderator was at a small regional conference. She was a behemoth of a woman who, as speakers reached their 15 min limit, would move to the stage tower over them ominously until they cowered in fright and stopped speaking.

  5. I've never heard of the Anholt book, but maybe I should pick up a copy.

    Moderators do indeed have a difficult job. At the meeting I was at, though, there was a timer sitting right in front of you that counted down exactly how much time you had left and then started blinking insistently a couple of minutes before the end.

  6. Just three tips;

    Rehearse early; this allows you to catch problems in the outline of your presentation and allows you to modify your slides accordingly.

    The second tip concerns fonts:
    Always include fonts with your Powerpoint presentation. Otherwise there's a chance all your pretty lambdas changed overnight into question marks. This is especially devastating in formulas. Consider ? = ? * e^? + ??. Or when you give a talk on phage lambda *as I once did).

    Quickly check your slides on the computers used during the conference. Usually there's ample time to do this during the breaks.

  7. I always give the following advice to friends about to give their first academic talk - don't refer to your talk after the first 30 seconds of the talk. For instance, 10 minutes into your presentation, you shouldn't say something like '... and I'll be getting back to this point later.'. If your talk is boring to begin with (and let's face it, we've all sat through boring talks at meetings wishing we had hit the bar instead), no one wants to be reminded that it's not almost over!


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