Interactive
Play with the data
8 demos taken from the figures in Volume 1. Move the points and the sliders, and watch what happens to the correlation. Each one arrives at the same number as the slide it came from, worked out in your browser rather than typed into the page.
Volume 1 · Correlations
8 demos from this volume
Four datasets, one correlation. r = 0.82 every time.
Drag a point. Watch the two coefficients disagree.
Narrow the sample, watch a strong correlation vanish.
At n = 25 the estimate swings. At n = 200 it settles.
Add noise to either measure, watch r pull toward zero.
One nested dataset, three different correlations.
Cut two measures into Likert categories and watch Pearson lose what polychoric keeps.
Push a distribution against its scale boundary.
Later volumes will add their own set here, under their own heading.
How these work
Everything runs in your browser
Each demo uses a small synthetic dataset built for it and shipped with the page. Nothing you drag or type is sent anywhere, and there is nothing to sign up for. The datasets and the script that makes them are in the resources.