I have found that generating large numbers of ideas doesn't imply a larger number of potential nuggets. The free-association aspect of traditional brainstorming is often more useful as a means of mapping the preoccupations and thinking-styles of a group than in generating useful ideas.
Another difficulty is that the first idea voiced in traditional brainstorming, may prove to be the last. I have noticed that extended stress-gaps in teams, combined with a high need to produce an output, can lead to the generation of ideas long before the team has agreed and formally defined the problem. Such teams are easily led astray by the first idea. It is as though the first idea dominates or "shapes" everything that follows to develop an inadvertent “groupthink”.The need to work on something, often anything, can mean that the first idea voiced, slants or influences the expectations of the group and can misdirect all the ideas that follow. The team embellishes the initial idea, producing variations and investing in this direction until, much too late, it realises that this area is rather unproductive but feels unwilling to abandon work that has involved so much emotion, time and effort.
Ideas can be vetted inadvertently. I have seen facilitators scribbling ideas down onto flipcharts as the team shouted them out in traditional brainstorming style and noticed their unconscious vetting of ideas that they disliked by not writing them down. When asked subsequently why they missed these ideas and ultimately switched those individuals off from any further positive contributions, they simply said that they had not heard the ideas.When revisited on video, the excluded ideas sounded just as loud as the other "acceptable" ideas.
The solution to overcome this type of "groupthink" is to introduce a new discipline to traditional brainstorming, by asking individuals to "kick-off" the process of generating solutions or ideas by doing it individually, and in silence and recording their ideas on Post-Its.This "Creative Silence" approach leads to a significant improvement in quality and diversity of ideas. The resulting ideas are collected by asking individuals to contribute their ideas in threes, and without comment, working round the team until all the ideas are represented. This also encourages individuals to listen to each others' ideas to avoid presenting the same idea again.
I find Post-Its for individuals a very useful way of accelerating this process. I have no investments in the manufacturers, nor do I (as yet) receive a retainer for making this suggestion! Remember: One idea per Post-It, write all ideas with the same colour flipchart-pen, to disguise the ownership of ideas and reduce status-awareness.
A minor point to remember is that ideas may need to be expressed in more than just a single word on a Post-It in order to mean something to other team-members.
Encourage individuals to introduce their Post-Its in their own words, without comment from the team beyond checking their understanding of the necessarily abbreviated content of each Post-It as it is put on display.
If used correctly, this tool will help you and your team to effectively generate useful solution in a relatively short period of time. Its success however, depends upon your process discipline!
[Extract from: “The First Discipline: Process Leadership for Problem Solving Teams”, Victor Newman, 2010, http://www.blurb.com/bookstore/detail/2606757]