Expansion Joints

Back in the days when I did live talks, one of my abilities was to finish on time, even if my talk time was cut at the last moment (perhaps due to the prior speaker running over). The key to my ability to do this was to use Expansion Joints - parts of the talk that I'd pre-planned so I could cover them quickly or slowly depending on how much time I had.

The way I'd do this would be to plan for some topics to be optional. The talk would work if I skipped over them, but I could also witter on about them for five (or ten) minutes. Ideally, each of these topics would get one slide, usually with a bunch of key phrases on it - the headings of what I'd talk about should I be talking about it. When I got to the slide, I'd look at how time was going with the talk. If (as was usually the case) I was running short of time, I could cover the slide in about thirty seconds, saying something like: “in doing this, there's a bunch of things you need to consider, but they are out of scope for today's talk”.

If, however, I did have time, I could then spend some time talking about them. The slide would be simple, and not provide much of a Visual Channel, but that wasn't so important, after all this material was optional in the first place.

The single flex-slide was my favorite Expansion Joint, as it was easy to use. Sometimes however my optional topic required a proper visual channel, necessitating dedicated slides. My solution here was good control over slide handling. Presentation tools include the ability to skip over slides while I'm talking, and I made sure I practiced how to use them so I could skip a bunch of slides without the audience knowing. It's crucial here that it's invisible to the audience, I find it looks sloppy if anyone says “in the interests of time I'll skip over these slides”. To do this, however, I do need access to my laptop while presenting, venues that only provide a clicker while loading the slides on some other machine lack that control. That started to happen in my last couple of years, much to my annoyance.

When creating talks, I was always worried that I would run out of things to say, even though experience told me I reliably crammed more stuff in than I could possibly cover. Expansion Joints helped with this, I could aggressively trim the core talk to less than I needed, and rely on the Expansion Joints to fill the gap. In practice I usually didn't need the Expansion Joints anyway, but their presence helped my confidence.

Using Expansion Joints was particularly important for me as I never rehearsed my talks. I was always someone whose ability to present was driven by adrenaline. Talking to a rubber duck just didn't work, the duck was clearly every bit as bored as I was. Consequently the first time I gave a talk, I was hazy as to how long it would take. Yet with Expansion Joints in place, I was able to finish a talk right on time.

Expansion Joints enabled me to give the same talk to different time slots. Sometimes I'd have thirty minutes, sometimes forty-five. With Expansion Joints, I didn't need to change my slides, particularly handy if a time cut (or more rarely a time increase) appeared at the last moment. (Although in my later years, I handled this by doing a Suite Of Talks.)

Talks that encourage audience interaction need these because we can never predict how much time the interaction will use up. Sometimes we get a steady stream of questions, other times (particularly in Scandinavia, or upper-Midwest America) a lack of questions had me blasting through the agenda. Any such talk needed a double-dose of this temporal ballast.

Expansion Joints are at their most useful in later parts of the talk, as it's then that I have the most information on how much time I have. Earlier ones can still be handy, particularly if they come after an interactive section when I'd like to rebase my timing.