DS-301b · Module 1

Chart Anti-Patterns

3 min read

Seven anti-patterns account for 90% of bad data visualization. The vanity chart: a chart that looks impressive but communicates nothing actionable. The shapeshifter: changing chart types between slides when the data relationship has not changed. The orphan: a chart with no title, no axis labels, and no context. The truncated axis: starting the y-axis at a non-zero value to exaggerate differences. The pie with too many slices: more than five segments and the human eye cannot distinguish proportions. The dual-axis deception: two y-axes on different scales that suggest correlation where none exists. The 3D distortion: adding a third dimension to a 2D chart that distorts the visual proportions. Each anti-pattern introduces a specific type of miscommunication. Each is easily avoided when you know what to look for.

Do This

  • Audit every chart against the seven anti-patterns before publishing
  • Start the y-axis at zero unless there is a documented, disclosed reason not to
  • Limit pie charts to five or fewer segments — use a bar chart for more categories

Avoid This

  • Use 3D charts ever — the third dimension distorts proportions without adding information
  • Use dual axes without clearly explaining both scales — the visual suggests a relationship the data may not support
  • Publish a chart without a title, axis labels, and data source — context is not optional