Brainstorming is a group creativity technique by which efforts are made to find a conclusion for a specific problem by gathering a list of ideas spontaneously contributed by its members. The term was popularized by Alex Faickney Osborn in the 1953 book Applied Imagination.

Osborn was an advertising executive and he started developing methods for creative problem solving in 1939. Because of his frustration on his employees’ inability to develop creative ideas individually for ad campaigns, he began hosting group-thinking sessions and in effect discovered a significant improvement in the quality and quantity of ideas produced by employees. Osborn outlined his method in the 1948 book Your Creative Power, specifically in Chapter 33.

Osborn claimed that there are two principles that contribute to “ideative efficacy” and these are: (1) Defer Judgment and (2) Reach for quantity.

He then followed with four general rules of brainstorming with the purpose of reducing social inhibitions among group members, stimulate idea generation, and increase overall creativity of the group. The four general rules are:

1. Go for 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 generate the bigger the chance of producing a radical and effective solution.

2. Withhold criticism – Instead, participants should focus on extending or adding to ideas, setting aside criticism later on for the ‘critical stage’ of the process. In this way, participants will feel free to generate unusual ideas.

3. Welcome wild ideas – this is probably the fun part. To get a good long list of suggestions, wild ideas are encouraged. They can be generated by looking from new perspectives and suspending assumptions. These new ways of thinking might give you better solutions.

4. Combine and improve ideas – combination of two ideas stimulate its building by a process of association.

Applications

Osborn notes that brainstorming should address a specific question; he held that sessions addressing multiple questions were inefficient.

Further, the problem must require the generation of ideas rather than judgment; he uses examples such as generating possible names for a product as proper brainstorming material, whereas analytical judgments such as whether or not to marry do not have any need for brainstorming.

There are variations:

Nominal group technique – Participants are asked to write their ideas anonymously. Then the facilitator collects the ideas and the group votes on each idea.

Group passing technique – This one starts by having each person in a circular group writes down one idea, and then passes the piece of paper to the next person, who adds some thoughts. This continues until everybody gets his or her original piece of paper back. By this time, it is likely that the group will have extensively elaborated on each idea.

Team idea mapping method – This method works by the method of association. It may improve collaboration and increase the quantity of ideas, and is designed so that all attendees participate and no ideas are rejected.

Directed brainstorming – Directed brainstorming works when the solution space (that is, the set of criteria for evaluating a good idea) is known prior to the session. If known, those criteria can be used to constrain the ideation process intentionally.

Guided brainstorming – A guided brainstorming session is time set aside to brainstorm either individually or as a collective group about a particular subject under the constraints of perspective and time.

Individual brainstorming – “Individual brainstorming” is the use of brainstorming in solitary or isolated situations. It typically includes such techniques as free writing, free speaking

Question brainstorming – This process involves brainstorming the questions, rather than trying to come up with immediate answers and short term solutions.

Most source: https://en.wikipedia.org/wiki/Brainstorming