Affinity Map

Purpose

Affinity Mapping (also known as Affinity Diagram or KJ Method) takes a chaotic collection of ideas, observations, or data and organizes them into meaningful groups based on natural relationships. It helps teams make sense of qualitative data, find patterns in research, and create structure from divergent brainstorming output.

At a glance

• Group size: 3–15
• Duration: 25 minutes
• Difficulty: Beginner
• Facilitation style: Collaborative sorting
• Setting: In-person or virtual

How to run

1. Spread the data (2 min). Place all sticky notes, ideas, or data points on a large wall or board — randomly, without organization.
2. Silent sorting (10 min). Participants silently move notes into groups that feel related. No talking — let the patterns emerge. It’s okay to move notes others have placed.
3. Name the clusters (5 min). Once groups stabilize, collaboratively name each cluster with a short header that captures the theme.
4. Discuss outliers (3 min). Review items that didn’t fit any group. Are they unique insights or noise?
5. Prioritize clusters (5 min). Dot-vote or discuss which clusters are most important to act on.

Materials needed

• Large wall space or digital whiteboard
• Sticky notes (already written from a prior brainstorm or research synthesis)
• Markers for cluster headers
• Dot stickers for voting

Pitfalls & common mistakes

• Pre-defining categories. Let groups emerge bottom-up; don’t impose top-down structure.
• Too few items. Affinity mapping works best with 30+ items. With fewer, just have a discussion.
• Talking during sorting. The silent phase forces pattern recognition without groupthink.

Inclusion & accessibility

• Read cluster names and contents aloud for participants who cannot see the wall.
• In virtual settings, assign a sorting facilitator for participants who have trouble using digital tools.
• Ensure the wall or board is at a reachable height for all participants.

Variations

• Affinity + How Might We: Convert each cluster header into a ‘How Might We’ question.
• Research synthesis: Use affinity mapping to cluster user interview quotes into themes.
• Retrospective affinity: Cluster retrospective feedback into actionable themes.

When NOT to use this

• When you have quantitative data that should be analysed statistically, not visually.
• When the group has fewer than 20 items to sort — a simple discussion is more efficient.

Source & further reading

• Kawakita, J. (1967). The KJ Method. *Chuokoronsha.*
• Beyer, H. & Holtzblatt, K. (1998). *Contextual Design.* Morgan Kaufmann.