About

Cleveland and McGill studied what people are able to decode most accurately and defined and ranked visual primitives in the following list.

  1. Position along a common scale e.g. scatter plot
  2. Position on identical but nonaligned scales e.g. multiple scatter plots
  3. Length e.g. bar chart
  4. Angle & Slope (tie) e.g. pie chart
  5. Area e.g. bubbles
  6. Volume, density, and color saturation (tie) e.g. heatmap
  7. Color hue e.g. newsmap

The ordering does not result in a precise prescription for displaying data but rather is a framework within which to work.