The participants your choose to be a part of a brainstorm are obviously important, but the there are numerous ways to decide who to include.

A Half & Half is a ideation and problem solving format that I use for small groups. The basic idea is a pretty simple and might be a way to add a new dimension to your next brainstorm...give it a try.

1) Invite a group of curious people together (I suggest no more than 8).

2) Make sure at least half are new faces

3) Try to include at least one “creative” (an artist, designer, etc), and at least one person who is radically outside your industry.

4) Have just one cental topic or question to explore.

You can run the discussion freestyle or use something more formal. Typical meeting/collaboration challenges will apply. It can help to have a facilitator and a note-taker.

Depending how you tweek the meeting, different outcomes can be reached. Perhaps you want to raise issues...asking broader questions might be in order. Perhaps you want to look at new angles of a problem your team is stuck on...have the old-hands describe the problem in a short 5 min presentation and then spend 20 minutes silently listing to the ideas of the newbies. 

There is a lot of talk about bring together interdisciplinary groups to solve problem but it is tough to execute. Often are networks are not as broad as we might think. You might consider inviting someone else to curate the newbie half of the meeting. 

As long as the participants are generally curious and open minded, good facilitation should be able to make the group work. If you don't have good facilitation, it still will be inclined to new ideas because of the new people. The main contribution of a Half & Half is in making a conscious curatorial decision to bring in new perspectives and to bring in enough of them that they have a voice in the room.

- There are a few principles at work here will encourage new ideas.

1) Having new people who are not versed in the social dynamics and history of the problem you are trying to solve forces the old-hands to look at each other and the problem anew.

2) Sometime there is already an appropriate solution available and in common use in a different industry.

3) Conflicts are good when trying to generate ideas, as long as they support the meeting goal. New perspectives introduce new conflicts of interest and vision that encourage the participants to be creative.

4) Participants from outside your industry will have a harder time seeing the kind of specific applications your group might be jumping to already. When trying to generate new ideas, holding off on looking for application is your friend.

I use these principles often when putting together Double Happiness Workgroups.

Good luck.