Brainstorming (ブレーンストーミング) is an idea-generation method in which several people say whatever comes to mind, without criticism, so the ideas keep multiplying.
Rule
What it looks like in the room
No criticism
Nobody cuts in with “that won't work”; judgment waits until later
Free-wheeling
Even ideas that sound off-target get said out loud
Quantity over quality
Raise the count first, and leave good or bad for later
Piggybacking is fine
Add to someone else's idea, or combine it with another
This stage of spreading ideas out is called divergence (発散). Putting off evaluation and selection makes people less hesitant to speak, so the ideas can range from candidate product names to event plans.
AnalogyThink of opening a tap all the way and letting it run. If someone starts closing the valve midway, the flow thins out.
How to rememberA storm tears through and leaves a mess, so picture one blowing through your head: the tidying up comes afterward.
Exam points
ExamIn brainstorming (ブレーンストーミング), nobody rates a remark on the spot, and quantity comes before quality (質より量).
ExamOutlandish-sounding ideas are welcome (自由奔放), and feasibility is no reason to hold a remark back.
ExamImproving on an idea someone else raised (便乗) is allowed. An idea doesn't have to be wholly your own.
Brainwriting (ブレーンライティング) is an idea-generation method in which ideas are written on sheets and passed around, with each person adding to what they receive.
Write ideas
Pass it on
Add to what you receive
Stop after the set rounds
After passing and adding for the agreed number of rounds, the sheets are full of ideas.
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Participants stay silent and hand their sheets to the next person at fixed intervals. A well-known version is the 635 method, in which six people each write three ideas every five minutes. Because everyone writes at once with no waiting for a turn to speak, ideas also come in from people who find speaking up difficult.
AnalogyImagine a round-robin story, with one story per person all running at once. Everybody continues the one in front of them at the same moment, then hands it along.
How to rememberThe answer is in the name: “storming” became “writing,” so the pen replaces the voice.
Exam points
Mix-upBrainstorming (ブレーンストーミング) has people voice their ideas, while brainwriting (ブレーンライティング) has them write in silence and pass the paper along. Both are ways to increase the number of ideas.
The affinity diagram method (親和図法) sorts collected ideas and opinions into groups by how close their content is, revealing the structure of the whole.
One item per card
Gather similar cards
Add headings
Map the relationships
Show how the piles relate with lines and placement, so the overall structure becomes visible.
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This stage of pulling together the finished set of ideas is called convergence (収束). With no categories fixed in advance, you may notice groupings you hadn't anticipated.
AnalogyIt's like sorting loose photos into piles that share a mood, then giving each pile an album name.
How to remember“Affinity” means a natural liking between two parties, so picture ideas clustering with the ones they get along with.
Exam points
ExamThe affinity diagram method (親和図法) handles sorting and organizing ideas a group has already produced, not coming up with them in the first place.