In my previous life I had to give talks on a regular basis usually running from around 15 minutes to 60 minutes (questions included), although a few were 10 minutes and 120 minutes respectively. I found the size of the audience (usually 10-300) never really matters as much as its composition, here experts are easier to “handle” than non-experts, because the latter may misunderstand the subject and ask strange questions(*).

(*) My favorite one being the nuclear physicist who was trying to use the optical theorem (quantum wave scattering) to try to understand a binary star collision.

There is one golden rule when it comes to giving talks and that is “Don’t get derailed!”. Other than that, there are two ways to give talks.

First there’s the linear process. In the linear process, you cover 1/3 of introduction, 1/3 of intermediate stuff, and 1/3 of advanced stuff. Normal attention spans, even for people who have trained for years to sit quietly and listen, is around 17 minutes. Hence, try to make your introduction as good as possible … 17 minutes is just about your introduction in a standard seminar. Of course this could also suggest that people lose their focus once they no longer understand what you’re talking about. Personally, I have, therefore, broken this role and done 2/3 of introduction and 1/3 of advanced stuff. I feel that if people aren’t learning something, they’re wasting their time. The problem with the linear approach is that it is very susceptible to derailing. Every slide needs to be superbly timed. Also, if people get lost, they are really lost.

The other approach is the onion approach or the spiral approach.
The idea here is to start be describing the complete approach as simple as possible leaving out a lot of details. Then process is described again in somewhat more detail. And then a third time.
This approach can not be derailed (mainly because there is no rail). On the other hand it can not make rapid progress. In fact progress is hard to quantify.

In my martial arts training, I have noticed that karate uses a linear approach to teaching. You drill a set of techniques for a certain time and then you get tested in those before you start learning new techniques. Each new technique is quite different from previous techniques. Conversely, shinkendo uses the onion approach to teaching. Each technique has several levels starting with a couple of cuts and then progressively adding more cuts on the more advanced levels. While I have only tested for the first level, I know (a few) techniques from the fifth level.

The linear approach is the specialist’s approach whereas the onion approach is the generalist’s approach. A specialist needs to be competent in a single area, and thus always moving in one direction is the most effective approach. A generalist must be widely competent and thus can not afford not to know the wider environment, he is moving through.

The onion approach to teaching is much harder to implement because it has few precedents in our educational system, which of course is mainly designed to sort students into various vocations and teach them specialized skills. Hence, few people have much experience in teaching in this way. As well, few people have experience learning this way and will tend to find the onion approach unstructured and wavering.

For this blog, I have tried the linear approach already in the 30 day challenge and the problem here is clearly that people will get derailed by their inability to, say, move out, get rid of their car, or similar, basically making the rest of the “talk” a waste of time. I wonder, therefore, if the onion approach is not the superior way to teach something like early retirement. What do you think?

Originally posted 2009-06-19 12:11:46.