Know thy audienceAbout a month ago I went to a talk by a famous Russian professor, who came to talk about something very important he had contributed to mathematical physics thirty years ago. Now the room was filled with mathematicians, and there was also a handful of people from physics. If I remember correctly, the topic had its roots in Quantum Field Theory, a theory that I briefly touched upon when I still studied physics. Nevertheless I didn't understand at all what he was talking about, and looking around I estimated that at most ten percent of the audience might have a clue what he was talking about.
At most five of the fifty people were not completely wasting their time. No matter how ridiculous this may sound to an outsider, this is not at all uncommon for academic talks. So what was the rest of the audience doing there? Most probably thinking about their own research. Maybe many of them were actually thinking that the majority of the audience had no problems keeping up with the speaker. What I'm sure of is that after a countless number of incomprehensible talks, most of the idling ninety five percent had accepted this situation and learned how to cope with it.
Now before anybody rightfully accuses me of a holier-than-thou attitude, I have to admit that I was guilty of this as recently as three weeks ago. While my audience consisted of just three people, I think large parts of my talk might not have been understood because I assumed a wrong background. Talking for just a couple of minutes about their background could have prevented this. The solution is obvious: let there be no misunderstanding about the (target) audience from either side. Below I worked this out in a little more detail from the point of view of the audience, the speaker and the organizers.
What can the audience do? When you plan to go to a talk you should always try to find out what the level of the talk is going to be. Either contact the organizers (who often don't know this) or directly contact the speaker. If the talk is in the same building, don't shy away from going there and asking the speaker directly. This is just as beneficial for the speaker as for you: it allows him to become familiar with the audience and thus make a better connection. Once you feel that this talk is aimed at you, you no longer feel that if you don't understand the talk, then that is because you don't belong in this room. I often find it much easier to ask questions when I am sitting in the front, because you directly face the speaker and don't have to get past the audience first. Remember, asking questions also helps the speaker to make a connection with the audience.
What can the speaker do? Always discuss with the organizers what kind of audience you can expect. When you are able to send out an abstract, add a paragraph discussing the background that you assume your audience to have. Let there be no misunderstanding about the target audience. Just before the talk go around the audience, start establishing a connection, and find out what kind of people have come to the talk. For me this has as a side advantage that I tend to be a little less nervous whenever I see familiar faces in the audience. If done properly you will manage to give an understandable talk without boring people to death.
What can the organizers do? Discuss with the speaker what the target audience will be, and communicate this to the audience in the promotion of the event. Make sure there is an abstract of the talk containing a paragraph about the target audience. Ask the speaker to give more details about what he will talk about, and use this to reconsider the target audience. In short: be more than a medium, don't leave the communication up to the audience and the speaker.