Idea quantity or quality? What the research actually says
"No bad ideas, go for quantity." The facilitator says it, the timer starts, and forty minutes later the wall holds 80 sticky notes. When you read them back, they are variations of three ideas. Here is what the research behind the slogan actually supports, and what to change on Tuesday.
Where the slogan comes from
Alex Osborn, who popularised brainstorming in the 1950s, set "go for quantity" as one of its rules. The logic is simple: the more ideas, the more likely one of them is good. The rule travelled further than its context.
Researchers have since tested it (Diehl and Stroebe are the names most associated with the work). The finding that keeps coming back: people who generate ideas alone and then pool them produce more ideas, and often better ones, than the same people brainstorming out loud together. Two reasons carry most of the weight. Production blocking: only one person can speak at a time, and while you wait you lose your own idea. Evaluation apprehension: people water down what they say because the room is listening.
What the research supports, and what it does not
- More ideas raise the chance of a good one only when the ideas are different. Variations of one idea do not improve the odds, they only improve the count.
- Quantity works in silent, individual generation. It fails in loud group discussion, where the group follows the first two or three directions said aloud.
- In practice, quality depends more on the question and on who is in the room than on the count. A sharp question and one unexpected participant beat a longer list.
So the slogan is half right. Quantity helps, but only quantity of different ideas, and only where everyone can produce at the same time.
So what does that mean on Tuesday
- Generate alone and silently first, then pool. Five minutes of silence with a stack of notes before anyone speaks. Brainwriting 6-3-5 is the structured version and removes both blocking and apprehension in one move.
- Ask for different, not many. "Give me eight different answers" beats "as many as you can". The word different changes what people write.
- Change the question halfway through. A second prompt produces a second family of ideas. If the first round asked how to win new customers, the second asks what would make existing ones leave. Keep a few spare brainstorm questions ready.
- Bring in one outsider. Someone from another department, a customer-facing role or a new hire. Their notes rarely land in the existing clusters.
- Count clusters, not sticky notes. After the round, group the notes. The number of groups is your real yield. Say it out loud so the room learns what counts.
- Judge only after merging duplicates. Merge first, then evaluate. If you vote before merging, the biggest cluster wins on volume, not merit.
- Keep the three ideas nobody else had. Notes that stand alone are the ones most likely to be thrown away as noise. Mark them and carry them into the evaluation on purpose.
Signs of false quantity vs real quantity
| False quantity | Real quantity |
|---|---|
| 80 notes in 3 clusters | 25 notes in 12 clusters |
| Most notes rephrase the first idea said aloud | Notes from different people point in different directions |
| The wall filled fastest after the loudest person spoke | The wall filled during the silent round |
| Nobody can name an idea that surprised them | Two or three notes made the room go quiet for a second |
At the end of the generation phase, ask every person for their strangest idea. It is rarely the best one, but it often opens a cluster nobody had.
Judging while generating kills both quantity and quality. The two phases need a visible switch: a break, a different wall, or a different colour of note.
Mistakes that pass for productive ideation
- Counting notes as a success metric. "We produced 120 ideas" sounds good in the report and tells you nothing. Report clusters and what survived merging.
- The facilitator who merges too early. Grouping notes while people are still writing tells the room which directions are welcome. Wait until the silent round is over.
- Treating a long list as a result. A list is raw material. The result is the handful of ideas you can put into an impact and effort matrix and defend.
- No second question. One prompt gives one family of ideas, however long you run it. If the room goes quiet after ten minutes, the question is used up, not the people.
Score and prioritise ideas with your team
IdeaHone scores ideas against your criteria, shows them on a matrix and keeps the reasons, so the decision is clear and traceable.
Does quantity of ideas lead to quality?
Only when the ideas are genuinely different. More ideas raise the chance of a good one, but variations of the same idea do not count. Measure distinct clusters, not notes.
Is brainstorming effective according to research?
Classic out-loud group brainstorming is less effective than people generating ideas alone and then pooling them. The main reasons are production blocking (one person speaks at a time) and evaluation apprehension (fear of judgement). Silent generation first, discussion second, fixes most of it.
How many ideas should a workshop produce?
There is no right number. Set a target of clearly different directions, for example eight distinct answers per person per question, rather than a total count. A wall with 25 notes in 12 clusters beats 80 notes in 3.
