Fisher, Ronald Aylmer (1890–1962)

Ronald Aylmer Fisher was a statistician, eugenicist, evolutionary biologist, and geneticist who helped lay the foundations of modern statistical science. At an early age, Fisher's special abilities were apparent. Because of his poor eyesight—extreme myopia—he was forbidden to read with the aid of electric lights. In the evenings, his mother and teachers would read to him and provide instruction without visual aids. Fisher's exceptional ability to solve mathematical problems in his head and his geometrical approach to statistical problems are attributed to this early form of instruction.

Fisher obtained a bachelor's degree in mathematics from the University of Cambridge in 1912. The following year, he took a statistical job with the Mercantile and General Investment Company of London, a position he held for two years. Because of his poor eyesight, he was rejected for military service during World War I and spent the war years teaching mathematics and physics at various public schools. In 1917, he married Ruth Eileen Guinness. The marriage produced two sons and eight daughters.

In 1919, Fisher accepted the newly created position of statistician at Rothamsted Experimental Station, approximately 20 miles north of London. The career move proved to be a fortunate choice. It brought him into close contact with researchers who were concerned with the interpretation of agricultural field experiments and with laboratory and greenhouse experiments. Rothamsted provided an environment in which Fisher was free to pursue his interests in genetics and evolution; carry out breeding experiments on mice, snails, and poultry; and develop statistical methods for small samples.

While at Rothamsted, Fisher invented the analysis of variance and revolutionized the design of experiments. The publication of Fisher's books Statistical Methods for Research Workers in 1925 and The Design of Experiments in 1939 gradually led to the acceptance of what today are considered the cornerstones of good experimental design: randomization, replication, local control or blocking, confounding, randomized blocks, and factorial arrangements. Other notable contributions include the concept of likelihood and the maximum likelihood estimator, the development of methods suitable for small samples, the discovery of the exact distribution of numerous statistics derived from small samples, the Fisher information measure, and contributions to hypothesis testing. In 1933, Fisher succeeded Karl Pearson as the Galton Professor of Eugenics at University College, London. Ten years later, he accepted an appointment as the Arthur Balfour Chair of Genetics at Cambridge, a position he held until his retirement in 1957.

Friends described Fisher as charming and warm but possessing a quick temper and a devotion to scientific truth as he saw it. The latter traits help explain his long-running disputes with Karl Pearson and Pearson's son Egon. Fisher was the recipient of numerous honors and was created a Knight Bachelor by Queen Elizabeth in 1952.