MEPX
Chapter 8 of 10All chapters
  1. 1What a chart is for
  2. 2How people read charts
  3. 3Choosing a chart
  4. 4Axes and scales
  5. 5Colour
  6. 6Removing clutter
  7. 7Titles and annotation
  8. 8Showing distributions
  9. 9Time series
  10. 10Tools and workflow

Chapter 8 of 10

Showing distributions

Beyond the average.

Why it matters

Averages hide bimodality, skew and outliers. A histogram or box plot often overturns the conclusion a bar chart of means suggested.

  • Box plots show median, spread and outliers compactly.
  • With small samples, show the individual points.

Uncertainty

Error bars and confidence bands communicate that a value is estimated. Omitting them implies a precision the data does not have.