Why is your audience nodding off?

Any speaker would prefer his audience to be alertly nodding rather than nodding off (and snoring like hibernating bears).

I recently found an article in the Canadian Medical Association Journal that discussed the Incidence of and Risk Factors for Nodding Off at Scientific Sessions. It identified the following ten risk factors in a table, (and reported their odds ratios in decreasing order of significance as follows):

1) Monotonous tone (6.8)
2) Tweed jacket (2.1)
3) Losing place in lecture (2.0)
4) Poor slides (1.8)
5) Failure to speak into microphone (1.7)
6) After mealtime (1.7)
7) Dim lighting (1.6)
8) Warm room temperature (1.4)
9) Early morning (1.3)
10) Comfortable seating (1.0)

Monotonous tone topped the list for obvious reasons. However, I would not have expected that tweed jackets would be second.

They also provided a curiously detailed figure illustrating how the number of nodding off events per lecture varied with the length of the lecture. When you look carefully at the figure, you can see that it represents the head of a sleeping audience member in silhouette:











The tabulated risk factors should be taken with a very large grain of salt, since the article just is a rare example of scientific humor about presentations.

Yesterday on his Overnight Sensation blog James Feudo discussed Three Painless Ways to Avoid the Boring Talk.