Affinity Diagrams (KJ Method)

Origin. Jiro Kawakita (1960s); the KJ method for synthesizing qualitative data.

Mechanism. Groups items by felt similarity rather than by predefined categories. The categories emerge from the data rather than being imposed on it. Silent sorting prevents dominant voices from controlling the grouping; the structure that emerges reflects collective intuition.

Procedure. Write each observation, idea, or data point on a separate card. Spread all cards on a surface. Silently, without discussion, group cards that seem related. When the sorting stabilizes, name each group. Arrange groups spatially to show relationships. The named groups become the categories for further work.

Applies to. Qualitative research synthesis, requirements gathering, post-brainstorming organization, any situation with many items needing structure.

Limitations. Groups can be formed on surface features rather than meaningful relations. The named categories often reify the first grouping attempt rather than the best one. Revisit the grouping after naming; names reveal whether the grouping was principled.