The Mind's Shortcuts · heuristic
Pareto Principle (80/20)
Playable Play this law (~3 min)or keep reading below ↓
Roughly 80% of effects come from 20% of causes: most users touch a small fraction of features, most revenue comes from a few flows. Find your vital 20% and spend your design effort there — the long tail can live in menus.
Where it comes from
Italian economist Vilfredo Pareto noticed in 1896 that about 80% of Italy's land belonged to 20% of its people — and, famously, that 20% of the pea pods in his garden yielded 80% of the peas. Management thinker Joseph Juran generalised it in the 1940s as "the vital few and the trivial many," and it has described defect rates, sales and feature usage ever since.
Origin: Pareto's 1896 land-distribution observation (and his pea garden)
In the wild
- Word processors
Almost everyone uses bold, lists and headings; almost nobody uses mail merge — toolbars are ordered accordingly.
- Analytics products
One default dashboard covers what 80% of users check daily; everything else is a custom report.
- Support centers
Ten articles answer the vast majority of tickets — surface those ten, search handles the rest.
Further reading
Don't just read it — feel it.
Play the 3-minute game and let your own reactions prove the law.
Play the lesson