ICHEP is tomorrow, and I write this just as I’m about to jump on a TGV to transport me from the South of France (Marseille) to Paris. For an experimentalist the last several days have been full of practice talks (and they will continue to go on past the start of ICHEP). Everyone gives them from the most senior person on down.
That might seem funny… Even senior well established people give them. The reason is pretty simple: often it saves your bacon! This is especially true for the large overview talks that many people have to give. These are long – sometimes as long as 45 minutes, and frequently cover material that the person given the talk is not expert in. See the many CDF/DZERO combined talks that will occur at ICHEP. Since you can’t be a member of both experiments there is no way one person can possibly be an expert in both experiments! The practice talk is a chance for the two experiments to sit in the same room and give the speaker advice, tell them extra information in case they get a tricky question, etc.
The other thing it does is teach. This is especially true when you are just starting out. In experimental particle physics we are constantly giving talks to our colleagues – those on ATLAS or perhaps on CMS, depending on which experiment we work. But these talks are full of jargon (“B layer”, “layer zero-zero”, etc. – who is going to guess what those are and what experiment??). Sometimes we get so used to the jargon we forget it is jargon. When I was a graduate student and beginning post-doc I had a lot of trouble with this. Practice talks were a great way to have people spot it.
Another thing is TIME. Ugh. The clock. When you are giving a talk about 50% of your concentration is focused on delivering the material, watching the audience to see if they are falling asleep, or they looked confused or puzzled. The other half is constantly checking the clock and the slide number to make sure you are still in sync. The good folks who run the session are charged with one thing above all: keep it on time. And if you go over, they can get pretty aggressive. This can be difficulty because usually the most interesting slides are the ones that come last – they contain the punch-line, the measurement, THE PLOT. So, it sucks to have to rush through that!
Finally, the old maxim: practice makes perfect. By forcing you to have a draft of the talk several days ahead of time, you have several days to do polish work. Rather than just getting the major parts of the talk up the night before you have to give it.
I remember when we started doing practice talks in DZERO – the average quality of our presentations at conferences went way up! I don’t know of any large experiment that doesn’t do this now.
How about theorists? What do they do…? :-)