Brainstorming

Brainstorming is a creativity technique in which a group of people interact to suggest ideas spontaneously in response to a prompt. Stress is typically placed on the volume and variety of ideas, including ideas that may seem outlandish or "off-the-wall". Ideas are noted down during the activity, but not assessed or critiqued until later. The absence of criticism and assessment is intended to avoid inhibiting participants in their idea production. The term was popularized by advertising executive Alex Faickney Osborn in the classic work Applied Imagination.

History

In 1939, the American advertising executive Alex Faickney Osborn began developing methods for creative problem-solving. He was frustrated by employees' inability to develop creative ideas individually for ad campaigns. In response, he began hosting group-thinking sessions and discovered a significant improvement in the quality and quantity of ideas produced by employees. He first termed the process as organized ideation, but participants later came up with the term "brainstorm sessions", taking the concept after the use of "the brain to storm a problem".
During the period when Osborn made his concept, he started writing on creative thinking, and the first notable book where he mentioned the term brainstorming was How to Think Up.
Osborn outlined his method in the subsequent book Your Creative Power, in chapter 33, "How to Organize a Squad to Create Ideas".
One of Osborn's key recommendations was for all the members of the brainstorming group to be provided with a clear statement of the problem to be addressed prior to the actual brainstorming session. He also explained that the guiding principle is that the problem should be simple and narrowed down to a single target. Here, brainstorming is not believed to be effective in complex problems because of a change in opinion over the desirability of restructuring such problems. While the process can address the problems in such a situation, tackling all of them may not be feasible.

Osborn's method

Two principles

said that two principles contribute to "ideative efficacy":

Defer judgment;
Reach for quantity.
Four rules

Following these two principles were his four general rules of brainstorming, established with intention to:

reduce social inhibitions among group members;
stimulate idea generation;
increase overall creativity of the group.

These four rules were:

Go for quantity: This rule is a way of enhancing divergent production, aiming at facilitation of problem solution through the maxim quantity breeds quality. The assumption is that the greater the number of ideas generated the bigger the chance of producing a radical and effective solution.
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.
Welcome wild ideas: 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 better solutions.
Combine and improve ideas: As suggested by the slogan "1+1=3". It is believed to stimulate the building of ideas by a process of association.
Applications

Osborn said 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.

Groups

Osborn envisioned groups of around 12 participants, including both experts and novices. Participants are encouraged to provide wild and unexpected answers. Ideas receive no criticism or discussion. The group simply provide ideas that might lead to a solution and apply no analytical judgment as to the feasibility. The judgments are reserved for a later date.

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. The vote can be as simple as a show of hands in favor of a given idea. This process is called distillation.
After distillation, the top-ranked ideas may be sent back to the group or to subgroups for further brainstorming. For example, one group may work on the color required in a product. Another group may work on the size, and so forth. Each group will come back to the whole group for ranking the listed ideas. Sometimes ideas that were previously dropped may be brought forward again once the group has re-evaluated the ideas.
It is important that the facilitator is trained in this process before attempting to facilitate this technique. The group should be primed and encouraged to embrace the process. Like all team efforts, it may take a few practice sessions to train the team in the method before tackling the important ideas.

Group passing technique

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.
The group may also create an "idea book" and post a distribution list or routing slip to the front of the book. On the first page is a description of the problem. The first person to receive the book lists his or her ideas and then routes the book to the next person on the distribution list. The second person can log new ideas or add to the ideas of the previous person. This continues until the distribution list is exhausted. A follow-up "read out" meeting is then held to discuss the ideas logged in the book. This technique takes longer, but it allows individuals time to think deeply about the problem.

Team idea mapping method

This method of brainstorming 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.
The process begins with a well-defined topic. Each participant brainstorms individually, then all the ideas are merged onto one large idea map. During this consolidation phase, participants may discover a common understanding of the issues as they share the meanings behind their ideas. During this sharing, new ideas may arise by the association, and they are added to the map as well. Once all the ideas are captured, the group can prioritize and/or take action.

Directed brainstorming

Directed brainstorming is a variation of electronic brainstorming. It can be done manually or with computers. Directed brainstorming works when the solution space is known prior to the session. If known, those criteria can be used to constrain the ideation process intentionally.
In directed brainstorming, each participant is given one sheet of paper and told the brainstorming question. They are asked to produce one response and stop, then all of the papers are randomly swapped among the participants. The participants are asked to look at the idea they received and to create a new idea that improves on that idea based on the initial criteria. The forms are then swapped again and respondents are asked to improve upon the ideas, and the process is repeated for three or more rounds.
In the laboratory, directed brainstorming has been found to almost triple the productivity of groups over electronic brainstorming.

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. This type of brainstorming removes all cause for conflict and constrains conversations while stimulating critical and creative thinking in an engaging, balanced environment.
Participants are asked to adopt different mindsets for pre-defined period of time while contributing their ideas to a central mind map drawn by a pre-appointed scribe. Having examined a multi-perspective point of view, participants seemingly see the simple solutions that collectively create greater growth. Action is assigned individually.
Following a guided brainstorming session participants emerge with ideas ranked for further brainstorming, research and questions remaining unanswered and a prioritized, assigned, actionable list that leaves everyone with a clear understanding of what needs to happen next and the ability to visualize the combined future focus and greater goals of the group nicely.

Individual brainstorming

Individual brainstorming is the use of brainstorming in solitary situations. It typically includes such techniques as free writing, free speaking, word association, and drawing a mind map, which is a visual note taking technique in which people diagram their thoughts. Individual brainstorming is a useful method in creative writing and has been shown to be superior to traditional group brainstorming.

Question brainstorming

This process involves brainstorming the questions, rather than trying to come up with immediate answers and short-term solutions. The focus on different inquiries creates perspectives which may address the problem. Theoretically, this technique should not inhibit participation as there is no need to provide solutions. The answers to the questions form the framework for constructing future action plans. Once the list of questions is set, it may be necessary to prioritize them to reach to the best solution in an orderly way.
The portmanteau questorming is another term for this mode of inquiry.