Brainstorming with five people around a whiteboard is manageable. Brainstorming with fifty people, or two hundred, is a different challenge. Shouting out ideas doesn't scale, sticky notes become a wall of chaos, and the loudest voices take over.
The good news: large groups can produce a wide range of ideas if you give the session structure. A simple three-step approach works well: collect, cluster, prioritize.
Before you start: frame the question
The quality of a brainstorm depends heavily on the question. Vague prompts get vague ideas. Compare:
- Weak: "How can we improve the customer experience?"
- Stronger: "What frustrates customers in their first week with our product?"
- Stronger still: "What could we change in the first week of onboarding to reduce support requests?"
A focused question gives people something concrete to react to. If your topic is broad, consider running two or three shorter brainstorms on narrower questions instead of one huge one.
It also helps to decide in advance what happens with the output. Are you looking for quick wins to act on this quarter, or ideas to explore further? Tell participants, so they can pitch their ideas at the right level.
Step 1: Collect
The goal of the collection phase is volume and breadth. Judgment comes later.
Let everyone write at the same time. Silent, simultaneous idea generation is the biggest single improvement for large groups. Nobody waits their turn, and early ideas don't anchor the rest.
Set a time box. Five to eight minutes is usually enough. Announce when there's a minute left. A visible timer keeps energy up.
Allow multiple submissions. Encourage people to add as many ideas as they like. A few words per idea is ideal.
Consider anonymity. In a large or mixed-seniority group, anonymous submissions help people suggest unusual or critical ideas without worrying about how they'll be received.
Tip: Seed the first minute with one or two example ideas so people understand the level of detail you want.
Step 2: Cluster
With a large group, you might end up with dozens or hundreds of ideas. Clustering turns that pile into something you can actually discuss.
There are two ways to approach it.
Pre-defined categories. If you already know the main areas, set them up before the session and have people file their ideas as they submit. For an onboarding brainstorm, that might be "Product," "Documentation," "Support," and "Communication." The output is organized from the start.
Emergent categories. If you want to see which themes appear naturally, collect first and group afterward. With a big group, this works best if the facilitator or a small helper team does the grouping during a short break, then presents the themes back.
Either way, look for duplicates and near-duplicates. Ten people suggesting the same idea in different words is a strong signal, not noise.
Step 3: Prioritize
A brainstorm that ends with a long list and no direction is frustrating. The final step helps the group decide where to focus.
Start with reactions. Let participants react to the ideas they like most. This quickly surfaces popular ideas without a lengthy discussion.
Shortlist. Take the top five to eight ideas, based on reactions and on a realistic look at feasibility.
Rank. Ask the group to rank the shortlist. Ranking forces trade-offs in a way simple voting doesn't. People have to decide what matters most, not just what they like.
Discuss the result. Show the ranking and invite reactions. Is anything surprising? Are there concerns about the top choice? This is where a large group's collective view becomes useful input for decision-makers.
Common pitfalls to avoid
- Debating ideas during collection. It slows everything down and makes people self-censor. Save discussion for later.
- Too many categories. More than five or six makes filing confusing. Keep them broad.
- Running out of time. Protect at least a third of the session for clustering and ranking.
- No follow-up. If participants never hear what happened to their ideas, they'll be less enthusiastic next time. Share the top ideas and next steps within a week.
A sample agenda for a 60-minute session
- Welcome and framing the question (5 minutes)
- Warm-up word cloud on the topic (3 minutes)
- Silent idea collection (8 minutes)
- Review and react to ideas (10 minutes)
- Clustering and shortlisting (10 minutes)
- Ranking the shortlist (5 minutes)
- Discussion of results (15 minutes)
- Next steps and close (4 minutes)
Running it in LetMeAdd
LetMeAdd's brainstorming question is built for this flow. Participants join with a 6-character code or QR code, no account needed, and submit ideas into categories you set up. Everyone can react to the ideas they support, so the strongest ones stand out. Follow up with a prioritization question to rank the shortlist, and use a timer to keep each phase on track. There's also a ready-made brainstorm session template to start from.
When the session ends, export the results so the ideas don't disappear after the meeting.
Planning a big brainstorm? See how LetMeAdd works as an audience engagement platform, or sign up to try it.