Venn diagram encodes values as intersection area of overlapping closed curves. John Venn, 1880; Euler drew related region diagrams earlier.
In reports, ads and assignments it fits two or three sets with a real overlap story. Skip it when four-plus sets, or when sizes must be to scale.
Parts
- Mark — The core mark of Venn diagram is intersection area of overlapping closed curves.
- Scale — The scale must show zero (or a declared break) and units.
- Axis — Axis titles name the variable, not a mood.
- Legend — A legend is weaker than a direct label. Write beside the mark when you can.
- Label — Numbers are optional. If comparison is the job, label the ends only.
- Grid — Keep the grid faint. Data should own the ink.
- Annotation — One annotation sentence. Date the source.
- Frame — A thin frame. Never a 3-D box.
Variants
- Set circles — Variant 1 of Venn diagram. Same encoding, different layout.
- Euler cousin — Variant 2 of Venn diagram. Same encoding, different layout.
- Overlap map — Variant 3 of Venn diagram. Same encoding, different layout.
- Venn diagram 4 — Variant 4 of Venn diagram. Same encoding, different layout.
Labels
- Axis — On Venn diagram, make Mark readable.
- Legend — On Venn diagram, make Scale readable.
- Label — On Venn diagram, make Axis readable.
- Grid — On Venn diagram, make Legend readable.
- Annotation — On Venn diagram, make Label readable.
Venn diagram: honour intersection area of overlapping closed curves, and switch when four-plus sets, or when sizes must be to scale.