25/10 Crowd Sourcing

Purpose

25/10 Crowd Sourcing rapidly surfaces and prioritises the boldest ideas in a large group. By combining anonymous idea generation with iterative scoring, it identifies the proposals with the most collective support in under 25 minutes. Use it when a group needs to generate and rank ideas quickly, especially after a divergent brainstorming session.

At a glance

• Group size: 15–100+ people
• Duration: 25 minutes
• Difficulty: Beginner
• Facilitation style: Structured
• Setting: Indoor

How to run

1. Write ideas (3 min): Each person writes one bold idea on an index card.
2. Mill and score — Round 1 (3 min): Everyone stands, mills around the room, and passes cards randomly. When the bell rings, each person reads the card they are holding and scores it 1–5 on the back.
3. Repeat (3 min x 4 rounds): Pass, read, score. After 5 rounds, each card has 5 scores.
4. Tally (3 min): Each person totals the scores on the card they are holding. Facilitator asks: "Who has 25? 24? 23?..." until the top 5–10 ideas are identified.
5. Share (5 min): The holders of the top-scoring cards read them aloud. Brief discussion.

Materials needed

• Index cards (one per person)
• Pens
• Open space for milling
• Bell or timer

Pitfalls & common mistakes

• Allowing people to peek at previous scores — scores must be independent.
• Not enough milling rounds — five rounds ensures statistical robustness.
• Cards with vague ideas score low — coach participants to write specific, actionable proposals.

Inclusion & accessibility

• Anonymity protects junior voices and unconventional ideas from dismissal.
• The physical milling can be adapted for seated participants by having neighbours pass cards instead.
• Remote alternative: use a digital tool where cards are randomly redistributed and scored.

Variations

• 25/10 + 1-2-4-All: After identifying top ideas, use 1-2-4-All to discuss and refine them.
• Themed 25/10: Restrict ideas to a specific domain ("customer experience improvements only").
• 25/10 with rationale: After scoring, ask the final holder to add one sentence explaining the idea's appeal.

When NOT to use this

Avoid 25/10 when the group needs deliberative, nuanced evaluation — the method favours bold, pithy proposals and can disadvantage complex ideas that need explanation.

Source & further reading

Developed by Henri Lipmanowicz and Keith McCandless as part of Liberating Structures. See liberatingstructures.com.