In today's Wall Street Journal, the Cubicle Culture column discusses why brainstorm sessions can easily suck. From the article:
The popularity of brainstorming results in part from corporate America's knee-jerk faith in teams. In fact, the father of brainstorming, advertising executive Alex Osborn, advocated using people to storm a corporate problem "in commando fashion." And let yourself be labeled a "nonteam player," and you might as well start your own one-person consultancy.
But teams aren't necessarily so great. "There are so many things people do in management because they think it's good, but there's no evidence for it," says Paul B. Paulus, a professor of psychology at the University of Texas at Arlington. "Teamwork is one example. Brainstorming is another." Prof. Paulus conducted research on the number and quality of ideas of four people brainstorming together versus four people brainstorming by themselves. Typically, group brainstormers perform at about half the level they would if they brainstormed alone….
David Perkins, a professor at the Harvard Graduate School of Education, warns that sometimes group sessions can result in one person's bad idea tainting and limiting the range of others' ideas. "The best way to get good ideas is to get people to write them down privately and then bring them in," he says. You want group diversity but no more than five to seven people or you risk ending up with "coblabberation."