Bliki: 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 ta