DS-301b · Module 2

Small Multiples and Faceted Views

3 min read

Small multiples are the most underused and most powerful visualization technique. The concept: instead of one complex chart with twelve lines, create twelve simple charts with one line each. Same axes, same scale, different data. The human eye compares patterns across the twelve panels instantly. The twelve-line chart is a tangle. The twelve-panel layout is a comparison. Small multiples work because they leverage the eye's ability to compare spatial patterns rather than decode overlapping lines. The technique applies to any repetitive comparison: revenue by segment, engagement by channel, conversion by cohort. Whenever the question is "how does this metric compare across categories," small multiples is the answer.

Do This

  • Use small multiples when comparing the same metric across more than four categories
  • Keep axes consistent across panels — the comparison depends on identical scales
  • Order panels meaningfully — by performance, alphabetically, or chronologically, not randomly

Avoid This

  • Overlay twelve series on one chart — the result is unreadable above four or five series
  • Use different scales across small multiple panels — it destroys the visual comparison
  • Use small multiples for unrelated metrics — they work for comparisons, not dashboards