这篇主要介绍了卡尔·皮尔森的生平以及他的主要成就
Karl Pearson was a major player in the early development of statistics as a serious scientific discipline in its own right. He founded the Department of Applied Statistics (now the Department of Statistical Science) at University College London in 1911; it was the first university statistics department in the world. The present departments of Statistical Science and Computer Science, as well as the Genetics and Biometry group in Biology and the physical side of Anthropology are all part of his legacy to UCL.
Karl Pearson was born in London on the 27th March 1857. Karl Pearson's mother Fanny Smith and his father William Pearson were both from Yorkshire families. William was a barrister of the Inner Temple:He was a man of great ability, with exceptional mental and physical energy and a keen interest in historical research, traits which his son also exhibited(H M Walker).
William and Fanny named their second child Carl and he used this name until he was about 23 years old when he changed the spelling to Karl.
Karl, together with his one older brother and one younger sister, were brought up in an upper-middle class family. After being educated at home up to the age of nine years, he was sent to University College School, London. He studied there until he was sixteen, but he was then forced to leave due to illness. A private tutor was engaged to teach him at home and he took the Cambridge Scholarship Examinations in 1875 and, coming second in the examinations, he won a scholarship to King's College.He was educated privately at University College School, after which he went to King's College Cambridge to study mathematics. He then spent part of 1879 and 1880 studying medieval and 16th century German literature at the universities of Berlin and Heidelberg - in fact, he became sufficiently knowledgeable in this field that he was offered a post in the German department at Cambridge University.
Karl Pearson was born in London on the 27th March 1857. He was educated privately at University College School, after which he went to King's College Cambridge to study mathematics. He then spent part of 1879 and 1880 studying medieval and 16th century German literature at the universities of Berlin and Heidelberg - in fact, he became sufficiently knowledgeable in this field that he was offered a post in the German department at Cambridge University.
His next career move was to Lincoln's Inn, where he read law until 1881 (although he never practiced). After this, he returned to mathematics, deputizing for the mathematics professor at King's College London in 1881 and for the professor at University College London in 1883. In 1884, he was appointed to the Goldshmid Chair of Applied Mathematics and Mechanics at University College London. 1891 saw him also appointed to the professorship of Geometry at Gresham College; here he met W.F.R. Weldon, a zoologist who had some interesting problems requiring quantitative solutions. The collaboration, in biometry and evolutionary theory, was a fruitful one and lasted until Weldon died in 1906. Weldon introduced Pearson to Francis Galton, who was interested in aspects of evolution such as heredity and eugenics, and this was another very rewarding partnership, more for the developments in statistics it led to than for the eugenics, some of which is rather problematic for a modern reader with knowledge of subsequent developments.
Galton died in 1911 and left the residue of his estate to the University of London for a Chair in Eugenics. Pearson was the first holder of this chair, in accordance with Galton's wishes. He formed the Department of Applied Statistics, into which he incorporated the Biometric and Galton laboratories. He remained with the department until his retirement in 1933, and continued to work until his death in 1936.
Pearson married Maria Sharpe in 1890, and between them they had 2 daughters and a son. The son, Egon Sharpe Pearson, succeeded him as head of the Applied Statistics Department at University College.
Aside from his professional life, Pearson was active as a prominent free thinker and socialist. He gave lectures on such issues as "the woman's question" (this was the era of the suffragette movement in the UK) and upon Karl Marx. His commitment to socialism and its ideals led him to refuse an OBE (Order of the British Empire) when it was offered in 1920, and also a Knighthood in 1935.
Contributions to statistics
Pearson's work was all-embracing in the wide application and development of mathematical statistics, and encompassed the fields of biology, epidemiology, anthropometry, medicine and social history. In 1901, with Weldon and Galton, he founded the journal Biometrika whose object was the development of statistical theory. He edited this journal till his death. He also founded the journal Annals of Eugenics (now Annals of Human Genetics) in 1925.He published the Drapers' Company Research Memoirs largely to provide a record of the output of the Department of Applied Statistics not published elsewhere.
Pearson's thinking underpins many of the `classical' statistical methods which are in common use today. Some of his main contributions are:
(1)Linear regression and correlation
Pearson was instrumental in the development of this theory. One of his classic data sets involves the regression of sons' height upon that of their fathers'. Pearson built a 3-dimensional model of this data set (which remains in the care of the Statistical Science Department) to illustrate the ideas. The Pearson correlation coefficient is named after him.
(2)Classification of distributions
Pearson's work on classifying probability distributions forms the basis for a lot of modern statistical theory; in particular, the exponential family of distributions underling the theory of Generalized Linear Models.
And there are more examples of his contributions:
(3)Correlation coefficient.
The correlation coefficient (first conceived by Francis Galton) was defined as a product-moment, and its relationship with linear regression was studied.
Method of moments. Pearson introduced moments, a concept borrowed from physics, as descriptive statistics and for the fitting of distributions to samples.
(4)Pearson's system of continuous curves.
A system of continuous univariate probability distributions that came to form the basis of the now conventional continuous probability distributions. Since the system is complete up to the fourth moment, it is a powerful complement to the Pearsonian method of moments.
(5)Chi distance.
A precursor and special case of the Mahalanobis distance.
(6)P-value.
Defined as the probability measure of the complement of the ball with the hypothesized value as center point and chi distance as radius.
(7)Foundations of the statistical hypothesis testing theory and the statistical decision theory.
In the seminal "On the criterion..." ,Pearson proposed testing the validity of hypothesized values by evaluating the chi distance between the hypothesized and the empirically observed values via the p-value, which was proposed in the same . The use of preset evidence criteria, so called alpha type-I error probabilities, was later proposed by Jerzy Neyman and Egon Pearson.
(8)Pearson's chi-squared test.
A hypothesis test using normal approximation for discrete data.
(9)Principal component analysis.
The method of fitting a linear subspace to multivariate data by minimizing the chi distances.
(10)In the course of his studies of race, Pearson devised a Coefficient of Racial Likeness, calculated from several measurements of the human skull.
References
E S Pearson, Karl Pearson : An appreciation of some aspects of his life and work II, Biometrica29 (1938), 161-247.
E S Pearson, Some early correspondence between W S Gosset, R A Fisher and Karl Pearson,Biometrika 55 (1968), 445-457.
H M Walker, Karl Pearson, International Encyclopedia of the Social Sciences XI (New York, 1968), 496-503.
K Pearson, Old Tripos days at Cambridge, as seen from another viewpoint, Mathematical Gazette 20 (1936), 27-36.
Karl Pearson - Wikipedia, the free encyclopedia:
M Greenwood, Karl Pearson, Dictionary of National Biography, 1931-1940 (London, 1949), 681-684.
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