Udny Yule

George Udny Yule (February 18, 1871 – June 26, 1951) was usually known as Udny Yule, and was a Scottish statistician, born at Beech Hill near Haddington, Scotland and died in Cambridge, England.His father, also George Udny Yule, and a nephew, were knighted. His uncle was the noted orientalist, Sir Henry Yule. The Yule family had a reputation for scholarship and administration. He came from an established Scottish family composed of army officers, civil servants, scholars, and administrators.

At the age of 16, Udny began studying engineering at University College, London. He later moved to Bonn, Germany, where he studied under the famous scientist Heinrich Hertz. A great influence in his academic life was the statistician Karl Pearson, who lured him back to LondonFact|date=February 2008. Yule was a prolific writer, the highlight of his publications being perhaps the textbook "Introduction to the Theory of Statistics", which went through fourteen editions. He was active in the Royal Statistical Society, was awarded its Guy Medal in Gold in 1911, and served as its president in 1924-26. Frank Yates culminated his 1952 obituary of Yule by saying: “To summarize we may, I think, justly conclude that though Yule did not fully develop any completely new branches of statistical theory, he took the first steps in many directions which were later to prove fruitful lines for further progress… He can indeed rightly claim to be one of the pioneers of modern statistics” (Yates, 1952, p. 320).

Yule made important contributions to the theory and practice of correlation, regression, and association, as well as to time series analysis. The Yule distribution, a discrete power law, is named after him.

In 1899, Yule married May Winifred. The marriage was annulled in 1912, there having been no children (Yates, 1952).

Biography

Udny Yule was educated at Winchester College and at University College London where he read engineering. After a year in Bonn doing research in experimental physics under Heinrich Rudolf Hertz, Yule returned to University College in 1893 to work as a demonstrator for Karl Pearson, one of his former teachers. Pearson was beginning to work in statistics and Yule followed him into this new field. Yule progressed to an assistant professorship but he left in 1899 to a better-paid position as secretary to an examination board. He continued to publish articles and also a very influential textbook, "Introduction to the Theory of Statistics" (1911); his book was based on the lectures he gave as the Newmarch lecturer at University College. In 1912 Yule moved to Cambridge University to a newly created Lectureship in Statistics and he remained in Cambridge for the rest of his life. During the First World War Yule worked for the army and then for the Ministry of Food. A heart attack in 1931 left him semi-invalided and led to his early retirement. His flow of publications almost ceased but, in the 1940s he found new interests, one of which led to a book, "The Statistical Study of Literary Vocabulary".

Yule’s first paper on statistics appeared in 1895: "On the Correlation of Total Pauperism with Proportion of Out-relief". Yule was interested in applying statistical techniques to social problems and he quickly became a member of the Royal Statistical Society. For many years the only members interested in mathematical statistics were Yule, Edgeworth and Bowley. In 1897–99 Yule wrote important papers on correlation and regression); after 1900 he worked on a parallel theory of association. His approach to association was quite different from Pearson’s and relations between them deteriorated. Yule had broad interests and his collaborators included the agricultural meteorologist R. H. Hooker, the medical statistician Major Greenwood and the agricultural scientist Sir Frank Engledow. Yule’s sympathy towards the newly rediscovered Mendelian theory of genetics led to several papers.

In the 1920s Yule wrote three influential papers on time series analysis, "On the time-correlation problem" (1921), a critique of the variate difference method, "Why Do We Sometimes Get Nonsense Correlations between Time-series?" (1926), an investigation of a form of spurious correlation, and "On a Method of Investigating Periodicities in Disturbed Series, with Special Reference to Wolfer's Sunspot Numbers" (1927), which used an autoregressive model to model the sunspot time series instead of the established periodogram method of Schuster. Although Yule taught at Cambridge for twenty years, he had little impact on the development of statistics there. M. S. Bartlett recalled him as a "mentor" but his famous association with Maurice Kendall, who revised the "Introduction to the Theory of Statistics", only came about after Kendall had graduated.

elected works

*G. Udny Yule, "On the Significance of Bravais' Formulæ for Regression, &c, in the case of Skew Correlation", [http://visualiseur.bnf.fr/Visualiseur?Destination=Gallica&O=NUMM-56153 "Proceedings of the Royal Society of London", Vol. 60 (1896–1897)] , pp. 477–489.
*G. Udny Yule, "On the Association of Attributes in Statistics", [http://visualiseur.bnf.fr/Visualiseur?Destination=Gallica&O=NUMM-55999 "Philosophical Transactions of the Royal Society of London, Ser. A", Vol. 194 (1900)] , pp. 257–319.
*G. Udny Yule, "On the Theory of Correlation for any Number of Variables, Treated by a New System of Notation", [http://visualiseur.bnf.fr/Visualiseur?Destination=Gallica&O=NUMM-56172 "Proceedings of the Royal Society of London", Vol. 79 (1907)] , pp. 182–193.
*G. Udny Yule "Introduction to the Theory of Statistics" London Griffin 1911.
*G. Udny Yule, "A Mathematical Theory of Evolution, based on the Conclusions of Dr. J. C. Willis, F.R.S.", "Philosophical Transactions of the Royal Society of London, Ser. B", Vol. 213 (1925), pp. 21–87.
*G. Udny Yule, "On a Method of Investigating Periodicities in Disturbed Series, with Special Reference to Wolfer's Sunspot Numbers", [http://visualiseur.bnf.fr/Visualiseur?Destination=Gallica&O=NUMM-56031 "Philosophical Transactions of the Royal Society of London, Ser. A", Vol. 226 (1927)] , pp. 267–298.

External links

* [http://www.royalsoc.ac.uk/DServe/dserve.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqCmd=Show.tcl&dsqSearch=RefNo='EC/1921/22'&dsqDb=Catalog Royal Society citation]
*MacTutor Biography|id=Yule
* [http://human-nature.com/nibbs/04/yule.html George Udny Yule: Statistical Scientist]