The Galton board, also known as the Galton box or quincunx or bean machine (or incorrectly Dalton board), is a device invented by Francis Galton[1] to demonstrate the central limit theorem, in particular that with sufficient sample size the binomial distribution approximates a normal distribution.
Galton designed it to illustrate his idea of regression to the mean,[2] which he called "reversion to mediocrity" and made part of his eugenist ideology.[3]