Editing Pearson correlation coefficient (section)

==Naming and history==
It was developed by [[Karl Pearson]] from a related idea introduced by [[Francis Galton]] in the 1880s, and for which the mathematical formula was derived and published by [[Auguste Bravais]] in 1844.{{efn|As early as 1877, Galton was using the term "reversion" and the symbol "''r''" for what would become "regression".<ref>{{cite journal |first=F. |last=Galton |date=5–19 April 1877 |title=Typical laws of heredity |journal=Nature |volume=15 |issue=388, 389, 390 |pages=492–495; 512–514; 532–533 |doi=10.1038/015492a0 |bibcode=1877Natur..15..492. |s2cid=4136393 |url=https://books.google.com/books?id=eskKAAAAYAAJ&pg=PA512|doi-access=free }} In the "Appendix" on page 532, Galton uses the term "reversion" and the symbol ''r''.</ref><ref>{{cite journal |first=F. |last=Galton |date=24 September 1885 |title=The British Association: Section II, Anthropology: Opening address by Francis Galton, F.R.S., etc., President of the Anthropological Institute, President of the Section |journal=Nature |volume=32 |issue=830 |pages=507–510 |url=https://books.google.com/books?id=lN3RjXLUuWsC&pg=PA499}}</ref><ref>{{cite journal |first=F. |last=Galton |year=1886 |title=Regression towards mediocrity in hereditary stature |journal=Journal of the Anthropological Institute of Great Britain and Ireland |volume=15 |pages=246–263 |doi=10.2307/2841583 |jstor=2841583 |url=https://books.google.com/books?id=JPcRAAAAYAAJ&pg=PA246}}</ref>}}<ref>{{cite journal |first=Karl |last=Pearson |date=20 June 1895 |title=Notes on regression and inheritance in the case of two parents |journal=Proceedings of the Royal Society of London |volume=58 |pages=240–242 |bibcode=1895RSPS...58..240P |url=https://books.google.com/books?id=60aL0zlT-90C&pg=PA240}}</ref><ref>{{cite journal |last=Stigler |first=Stephen M. |year=1989 |title=Francis Galton's account of the invention of correlation |journal=Statistical Science |volume=4 |issue=2 |pages=73–79 |jstor=2245329 |doi=10.1214/ss/1177012580 |doi-access=free}}</ref><ref>{{cite journal |title=Analyse mathematique sur les probabilités des erreurs de situation d'un point |journal=Mem. Acad. Roy. Sci. Inst. France |series=Sci. Math, et Phys. |volume=9 |pages=255–332 |year=1844 |url=https://books.google.com/books?id=y3s_AAAAcAAJ&q=Sur%20Les%20Probabilit%C3%A9s%20des%20Erreurs%20de%20Situation%20d'un%20Point&pg=PA1 |via=Google Books |language=fr}}</ref><ref>{{cite journal |last1=Wright |first1=S. |year=1921 |title=Correlation and causation |journal=Journal of Agricultural Research |volume=20 |issue=7 |pages=557–585}}</ref> The naming of the coefficient is thus an example of [[Stigler's Law]].