Brainstorming is a group creativity technique designed to generate a large number of ideas for the solution of a problem. The method was first popularized in the late 1930s by Alex Faickney Osborn in a book called Applied Imagination. Osborn proposed that groups could double their creative output with brainstorming.

Although brainstorming has become a popular group technique, researchers have not found evidence of its effectiveness for enhancing either quantity or quality of ideas generated. Because of such problems as distraction, social loafing, evaluation apprehension, and production blocking, brainstorming groups are little more effective than other types of groups, and they are actually less effective than individuals working independently. In the Encyclopedia of Creativity, Tudor Rickards, in his entry on brainstorming, summarizes its controversies and indicates the dangers of conflating productivity in group work with quantity of ideas.

Although traditional brainstorming does not increase the productivity of groups, it may still provide benefits, such as boosting morale, enhancing work enjoyment, and improving team work.

Ground Rules 

Thus, numerous attempts have been made to improve brainstorming or use more effective variations of the basic technique.There are four basic rules in brainstorming. These are intended to reduce social inhibitions among groups members, stimulate idea generation, and increase overall creativity of the group.

1. Focus on quantity: This rule is a means of enhancing divergent production, aiming to facilitate problem solving through the maxim, quantity breeds quality. The assumption is that the greater the number of ideas generated, the greater the chance of producing a radical and effective solution.
2. Withhold criticism: In brainstorming, criticism of ideas generated should be put 'on hold'. Instead, participants should focus on extending or adding to ideas, reserving criticism for a later 'critical stage' of the process. By suspending judgment, participants will feel free to generate unusual ideas.
3. Welcome unusual ideas: To get a good and long list of ideas, unusual ideas are welcomed. They can be generated by looking from new perspectives and suspending assumptions. These new ways of thinking may provide better solutions.
4. Combine and improve ideas: Good ideas may be combined to form a single better good idea, as suggested by the slogan "1+1=3". It is believed to stimulate the building of ideas by a process of association.

Method 

Conclusion

Brainstorming is a popular method of group interaction in both educational and business settings. Although it does not provide a measurable advantage in creative output, brainstorming is an enjoyable exercise that is typically well received by participants. Newer variations of brainstorming seek to overcome barriers like production blocking and may well prove superior to the original technique. How well these newer methods work, and whether or not they should be classified as brainstorming, are questions that require further research.