As a facilitator who tries to avoid "group think" this article confirms my bias. According to the article:
Brainstorming in a group became popular in 1953 with the publication of a business book, Applied Imagination. But it’s been proven not to work since 1958, when Yale researchers found that the technique actually reduced a team’s creative output: the same numbers of people generate more and better ideas separately than together. (Emphasis added)
The article has several useful suggestions about how to generate ideas, and I commend it to your attention.
My thanks to a friend and colleague, Maile Beers-Arthur for circulating this article.