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Simpson's Paradox: When Grouped Trends Reverse

Interactive 3D data-science lab: watch a negative trend inside every subgroup flip into a positive trend once the groups are pooled together — a real, reproducible statistical illusion caused by a confounding variable.

Data Science3DAdvanced60 FPS

Every subgroup in this dataset shows the same negative relationship between X and Y — yet pool all the points together and the trend can flip to positive. This is Simpson's Paradox, a real and reproducible statistical phenomenon caused by a confounding variable that drifts together with both the predictor and the group label. The simulator generates several subgroups of synthetic data, fits a genuine least-squares regression line to each one individually and to the pooled dataset, and renders both in 3D so you can watch the local trend disagree with the global one as you turn up the confound strength.

⚙ Under the hood

Watch a negative trend inside every subgroup of a dataset flip into a positive trend once the groups are pooled together — a real statistical illusion driven by a confounding variable, rendered as an interactive 3D scatter plot with live regression fits.

statisticsdata-scienceregressioncorrelationconfounding-variable

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install