Effect Size Visualizer

Shows what different effect sizes (e.g. Cohen's d) actually look like as overlapping distributions.


What it does

  • Displays two group distributions with separation controlled by the effect size
  • Adjust Cohen's d to see how overlap changes
  • Builds intuition for practical significance vs statistical significance

Key concepts illustrated

  • A "small" effect (d = 0.2) has extensive overlap between groups
  • A "medium" effect (d = 0.5) still has substantial overlap
  • A "large" effect (d = 0.8) shows clearer separation
  • Statistical significance is not the same as practical importance

Cohen's d benchmarks

d Label
0.2 Small
0.5 Medium
0.8 Large

This is a teaching tool for building intuition about effect sizes.

A UniversalChatBot is available for discussion.