I am currently reading a fascinating article called "Groupthink: The brainstorming myth", by Lehrer (New-Yorker Magazine, Jan 30 2012).

It seems reasearch supports the claim that the process of brainstorming, where all criricism is suspended, people say whatever comes into their heads and the whiteboard is covered with sentences, does NOT actually achieve its goal of improving the ability to solve problems.

"Dissent simulates new ideas because it encourages us to engage more fully with the work of others and to reassess our viewpoints".

In the article they claim that "getting along well" and "staying positive" is simply not productive.

When thinking about the school system, I find brainstorming taking place in staff meetings and during lessons.

I believe the claims made in the article regarding how contesting, arguing and debating ideas get better results is very applicable to staff meetings. Criticism should be a part of a healthy and productive discussion.

However, the kind of brainstorming done in class isn't REAL brainstorming anyway, its hypothetical and over when the bell rings. Therefore, I would stick to the previous rule of no criticism. A group of teenagers is much more vulnerable / possibly more aggressive than a group of trained professionals. We want the children to  be exposed to a civilized discussion!