Most everyone knows what brainstorming is—the group idea generation process where any and all ideas are welcomed, and ideas can be combined or built upon. Not being “judgy” is key, etc.

But how many of us know how to assess the effectiveness of a brainstorming session? And how to make what may be a good process even better?

Compared to what?

Individuals in a group brainstorming session may generate many ideas—but how do those ideas compare with the number and quality of ideas that would be produced by the same number of individuals working alone generating their own ideas?

Many research studies and meta-analyses show that typical interacting face-to-face group brainstorming sessions produce fewer unique (non-redundant) ideas than do the same number of individuals working alone. The ideas generated in the typical face-to-face group are also of lower average quality than if the individuals had worked independently.

Why might this be?

Hearing the ideas of others has the effect of associatively cuing our ideas in the same direction as what we are hearing. This can be helpful if it occurs at the right time by cognitively stimulating our thinking in new and useful directions. But such associative cuing can be a big drawback if it occurs at the wrong time, or too soon, preventing us from reaching and articulating ideas we otherwise would have formed.

Another factor is that ideas compete with one another for emergence in our awareness and “bottlenecks” may be created while we wait our turn to speak.

As we observe in Innovating Minds: “Verbally expressing our ideas to the group too soon may lead to a single shared idea landscape—without the beneficial input of each individual’s contributions and successive reworkings. Variations on simpler face-to-face group brainstorming are attempts to avoid the drawbacks of jumping into a single idea space too soon.”

Brainstorming variants

So what should we do?

We might try brainwriting. Here we each individually and silently write down our ideas and place them on idea sheets in the center of a table. People in the group, when they feel they are ready, can select and read the ideas of others, adding to or elaborating on those ideas if they choose. Another approach is to pass the idea sheets along. In the 6-3-5 method: 6 people each generate and write down 3 ideas on their own. Then they pass them along 5 times, silently and in parallel building on the ideas of others, until the idea sheet returns to where it started.

Sketches rather than words could also be circulated this way or later displayed as a “gallery” of ideas. Or ideas could be generated individually and then selectively shared and later broadcast more widely electronically via a computer network.

Each of these are potential ways of maximizing the diverseness of our idea landscapes, reaping the cognitively stimulating benefits of encountering the ideas of others without incurring creativity costs. Such “pairs of pairs of pairs” methods allow varied contributions and intermeshing of the contributions of others in a way that can optimize both individual and group idea generation.

–> For a recent extensive review see: Wolfgang Stroebe, Bernard A. Nijstad, & Eric F. Rietzschel, “Beyond Productivity Loss in Brainstorming Groups: The Evolution of a Question” Advances in Experimental Social Psychology, Volume 43, 2010, Pages 157–203.