I never thought much about the time-expensiveness of scientific presentations, but, it occured to me during a talk I was attending lately (and the fact that it occured during a talk might also be relevant…) that the time invested in a 1 hour talk for 30 attendants is more than a person has available for work during a week.

1h presentation = (10h preparation) + (1h attending x 30) + (20min context switching x 30) = 50h = 6 working days

And, when you think that usually only 1 in 10 presentations is useful (if your experience does not tell you this, you can also see “The Craft of Scientific Presentations”) you will start to realize that doing a presentation is a serious responsibility an that puting in the effort to prepare a good presentation might be a first step towards a better world :)