Walter Frank Raphael Weldon - Weldon's Dice

Weldon's Dice

In 1894, Weldon rolled a set of 12 dice 26,306 times. He collected the data in part, 'to judge whether the differences between a series of group frequencies and a theoretical law, taken as a whole, were or were not more than might be attributed to the chance fluctuations of random sampling.' Weldon's dice data were utilized by Karl Pearson in his pioneering paper on the chi-squared statistic. As a project for a History of Statistics course taught at the University of Chicago, Zacariah Labby built a machine to roll the dice and automatically count the dots (pips) on each die. The resulting data allowed Labby to repeat Weldon and Pearson's original investigations, as well as delve deeper into the analysis.