As previously noted, I spent most of last week at the 2013 DAMOP meeting, where I listened to a whole bunch of talks. At some point, I was listening to a talk, and said “I bet this guy hasn’t given a lot of these before.” What was the give-away? The fact that he almost never said “Um.”
To the dismay of many students entering science majors, public speaking is a very significant part of being a professional scientist. Scientists are expected to give talks of a variety of different lengths– 10-15 minute “contributed” talks at big meetings, 25-30 minute “invited” conference talks, 45-60 minute seminars and “job talks.” Oral presentations are one of the most important ways in which we communicate scientific results to other scientists.
And yet, the way scientists do public speaking is… very odd. We place a great deal of importance on public speaking, and most professional scientific talks are meticulously prepared. And then they’re delivered in a way that attempts to make them seem like off-the-cuff presentations.
The factor that made me think the guy giving that DAMOP talk was new at this was that he had very clearly memorized a prepared text. It wasn’t quite a rote recitation– he managed to vary the inflection of his voice in the ways appropriate for normal human speech– but he clearly knew exactly what word came next in each sentence. And while that’s a fairly effective way to deal with giving a talk when you’re not comfortable doing it, it’s extremely unusual in scientific presentations, particularly in physics. I’ve been going to scientific talks for better than twenty years, now, starting with colloquia at Williams when I was an undergrad, and I only hear clearly memorized text a couple of times a year.
What’s much more standard is a talk where the speaker has put a great deal of thought into their slides, and the key ideas that need to be expressed on each, but where they try to make up the exact wording of the talk as they go. Which means that, when you hear talks from scientists with a lot of practice giving talks, you tend to hear “Um” a lot. And also verbal filler like frequent sentences starting with “So, we see that…”
It’s kind of a weird business in that respect. To some extent, of course, this is just what good public speakers do– during the last Presidential election, there was a fascinating comparison of Bill Clinton’s DNC speech in 2012 with the prepared text he had written, and it’s chock full of brilliant ad-libs, and also the occasional bit of folksy verbal filler (“Now, folks…”). But even Clinton was working off a prepared text projected in front of him on a Teleprompter. Which is something basically no professional scientist does.
Instead, we have a very strange relationship with our PowerPoint slides. The slide in the “featured image” at the top of this post is the title slide from one of my research talks, listing my collaborator on the original proposal, and the students and funding agencies who have contributed. A typical slide from the middle of the text looks like this:
That’s a fairly typical sort of slide for a scientific talk–if anything, it’s probably a little lighter on text than most of the slides I saw at DAMOP. The slide has a schematic diagram– in this case, a cartoon version of a proposed astrophysical detector using liquid neon as a scintillation medium. There’s also a list of important points regarding the proposal over on the left side; in the actual presentation, these are minimally animated, so I reveal each as I get to it– you only see the full thing at the end of the spiel, just before I change to the next slide.
The list-of-points thing is a little risky– people can generally read faster than you can talk, which is part of the reason for the minimal animation. Having the text present serves two purposes, though: one is as an aid to anyone who’s taking notes– which really does happen at conferences– but the most important function is as a reminder to the speaker. It’s considered bad form to explicitly speak from notes, as is common in the humanities, and so scientists use prepared slides with text to cue them as to the next key point. Which leads to a lot of “Um” and “Uh” as the speaker does the mental reconstruction of the text.
(There are occasional hints that this is a recent-ish development– if you look at some of the many videos of Feynman lecturing– this one, say– he’s frequently referring to notes, not using slides or an overhead projector. By the time I entered physics in the early 1990’s, though, everything was overheads, and a chalk-talk from notes was very rare. these days, it’s all PowerPoint or the equivalent.)
This is, as I said, a very strange situation when you stop to think about it. Professional scientists spend a great deal of time speaking in public, but we do it in a manner that is designed to maintain the pretense of spontaneity. And because of that, even experienced speakers frequently appear sort of amateurish compared to speakers in politics and business. Students are often specifically coached not to memorize a specific text, just the key points, and to invent the exact words as they go. And people who are clearly working from a carefully crafted script stand out as unusual in the context of a week-long meeting.
Why it is that we do this is one of the enduring social mysteries of science. It’s very deeply ingrained, though– even when I do public lectures, where I very deliberately eliminate almost all the text from the slides, I still don’t go from memorized text, but use the images on the slides to cue myself as to what to say next. The exact words are invented on the spot. Which allows for fewer really clever turns of phrase, and creates a lot of space for verbal filler.
(By the way, if you want to see the full presentation those slides above came from, to verify that the examples are fairly typical, here it is on SlideShare:
(That might not be the exact version I grabbed the screenshots from, but it’s very close.)