I'm thinking about next semester's seminar series today, and came across this fascinating exchange on Brad DeLong's blog about academic cultures regarding interruptions during a talk. At UL, we have a very sympathetic culture to the speakers who come here, and we're keen to engage their ideas without necessarily being overly critical. When I studied at the New School in New York, you'd want to bring a sword, bandages, and some vodka to any presentation given by an external speaker. And at NUI, Galway, it varied, depending on which members of the faculty were in the audience at the time---I remember there being blood on the walls at brown bag seminars, and more often than not it was mine. Read the comments to the post as well, the exchange is great.
Economists are used to situations in which you are supposed to be quiet until the paper-giver has finished speaking, only those are not "workshops" but rather "conference presentations." A conference presentation would, typically, have the presenter speak for 30 minutes, an assigned discussant speak for 10, the presenter respond for 5, and then 15 minutes for questions from the floor and answers by the presenter. It's not a discipline-wide norm that economists follow in workshops, but rather one specific to the format of the "workshop."
The difference between interrupting and non-interrupting cultures is not a simple and arbitrary choice of social norm, but instead reflects a judgment about whose words are likely to be most valuable to hear. In an "interrupting culture" the presumption is that everyone has read and thought about the paper beforehand, and that to spend half or more of the available time with the presenter simply summarizing the paper (or, worse, reading large chunks of it) is a waste of everybody's time. Much better to have people raise and argue the points that puzzled them or that they think need to be expanded at their appropriate place in the argument. Moreover, when questions are asked in non-interrupting cultures at the end of the seminar, they don't lead to any discussion: questions come in response to things the presenter said 15, 30, or 45 minutes ago, and lead to formulaic thrust-and-parry-and-end rather than any more complex discussion. Now in a conference, where the presenter and the discussant are up at front for a reason, and where many in the audience have indeed not read the paper, the noninterrupting culture format makes a certain amount of sense. But in a workshop it does not.
The noninterrupting culture format is, in the last analysis, one that does even the presenter no favors. It greatly diminishes the fraction of the audience that will read the paper beforehand--for everyone knows that the presenter is going to eat up the lion's share of the time going over it with everyone else sitting around like bumps on a log. A good presenter is more interested in what an intelligent and thoughtful audience thinks of his or her argument than in listening to himself or herself summarize the paper one more time. And if for some reason the presenter gets off on the wrong foot and does not make contact with the audience, then an interrupting culture gives the presenter clues that may allow him or her to adjust on the fly and reconnect. In a non-interrupting culture--no chance of that.