page_title: Ronald Fisher
section_title: Rothamsted Experimental Station, 1919–1933
hierarchical_section_title: Ronald Fisher / Career / Rothamsted Experimental Station, 1919–1933
caption_attribution_description: English: Rothamstead Research Centre Rothamsted_Experimental_Station
context_page_description: Sir Ronald Aylmer Fisher FRS was a British statistician, geneticist, eugenicist, and professor. For his work in statistics, he has been described as "a genius who almost single-handedly created the foundations for modern statistical science" and "the single most important figure in 20th century statistics". In genetics, his work used mathematics to combine Mendelian genetics and natural selection; this contributed to the revival of Darwinism in the early 20th-century revision of the theory of evolution known as the modern synthesis. For his contributions to biology, Fisher has been called "the greatest of Darwin’s successors".
  Fisher held strong views on race. Notably, he was a dissenting voice in the 1950 UNESCO statement The Race Question, insisting on racial differences.
  From 1919 onward, he worked at the Rothamsted Experimental Station for 14 years; there, he analysed its immense data from crop experiments since the 1840s, and developed the analysis of variance. He established his reputation there in the following years as a biostatistician.
  He is known as one of the three principal founders of population genetics.
context_section_description: In 1919, he began working at the Rothamsted Experimental Station for 14 years, where he analysed its immense data from crop experiments since the 1840s, and developed the analysis of variance (ANOVA). 
  In 1919, he was offered a position at the Galton Laboratory in University College London led by Karl Pearson, but instead accepted a temporary job at Rothamsted in Harpenden to investigate the possibility of analysing the vast amount of crop data accumulated since 1842 from the "Classical Field Experiments". He analysed the data recorded over many years and in 1921, published Studies in Crop Variation, and his first application of the analysis of variance ANOVA. In 1928, Joseph Oscar Irwin began a three-year stint at Rothamsted and became one of the first people to master Fisher's innovations.
  Between 1912 and 1922 Fisher recommended, analyzed (with heuristic proofs) and vastly popularized Maximum likelihood.
  Fisher's 1924 article On a distribution yielding the error functions of several well known statistics presented Pearson's chi-squared test and William Gosset's Student's t-distribution in the same framework as the Gaussian distribution and is where he developed Fisher's z-distribution, a new statistical method commonly used decades later as the F-distribution.
  He pioneered the principles of the design of experiments and the statistics of small samples and the analysis of real data.
  In 1925 he published Statistical Methods for Research Workers, one of the 20th century's most influential books on statistical methods. Fisher's method is a technique for data fusion or "meta-analysis" (analysis of analyses). This book also popularized the p-value, and plays a central role in his approach. Fisher proposes the level p=0.05, or a 1 in 20 chance of being exceeded by chance, as a limit for statistical significance, and applies this to a normal distribution (as a two-tailed test), thus yielding the rule of two standard deviations (on a normal distribution) for statistical significance. The 1.96, the approximate value of the 97.5 percentile point of the normal distribution used in probability and statistics, also originated in this book.
  "The value for which P = 0.05, or 1 in 20, is 1.96 or nearly 2 ; it is convenient to take this point as a limit in judging whether a deviation is to be considered significant or not."
  In Table 1 of the work, he gave the more precise value 1.959964.
  In 1928, Fisher was the first to use diffusion equations to attempt to calculate the distribution of allele frequencies and the estimation of genetic linkage by maximum likelihood methods among populations.
  In 1930, The Genetical Theory of Natural Selection was first published by Clarendon Press and is dedicated to Leonard Darwin. A core work of the neo-Darwinian modern evolutionary synthesis, it helped define population genetics, which Fisher founded alongside Sewall Wright and J. B. S. Haldane, and revived Darwin's neglected idea of sexual selection.
  One of Fisher's favourite aphorisms was "Natural selection is a mechanism for generating an exceedingly high degree of improbability."
  Fisher's fame grew and he began to travel and lecture widely. In 1931, he spent six weeks at the Statistical Laboratory at Iowa State College where he gave three lectures per week, and met many American statisticians, including George W. Snedecor. He returned there again in 1936.
caption: Rothamsted Research
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