## Co-relations and their measurement, chiefly from anthropometric data in Proceedings of the Royal Society of London 45, 1888, pp. 135–145 WITH Kinship and Correlation in North American Review, 150, 1890, pp.419-431 [TWO VOLUMES, TWOP PAPERS -- 1888 & 1890 SEMINAL INVENTION OF THE STATISTICAL CONCEPT OF CORRELATION]

1st Edition. 1st EDITIONS OF GALTON’S 1888 PAPER & HIS 1890. The1888 paper presents his invention of the concept of correlation coefficient. His extensive & detailed 1890 paper describes the evolution of his thinking & the development of his ideas, culminating in the invention of the concept itself. “The great stimulus for modern statistics came from Galton's invention of the method of correlation;” from the “very modest paper [1888 paper came]… a revolution of scientific ideas” (Porter; Pearson).

“If one individual can be credited as the founder of the field of behavioral & educational statistics [it] is Galton ... He is responsible for the terms correlation, discovered the phenomenon of regression to the mean, & is responsible for the choice of r (reversion or regression) to represent the correlation coefficient” (Clauser p. 440). “Contemporary scientists often take the correlation coefficient for granted [not] appreciating that before Galton…the only means to establish a relationship between variables was to deduce a causative connection. [Prior to Galton] there was no way to discuss let alone measure the association between variables that lack a cause-effect relationship” (Samuel, Correlation p. 26).

Cousin to Charles Darwin, in 1884 Galton founded the Anthropometric Laboratory where he gathered data by physically measuring of hundreds of people. Galton “was not merely interested in physical characteristics, as he claimed that intelligence is inherited. To demonstrate this, he needed a method to show the intelligence of one generation was co-related to that of the previous generation so that he might argue for the causal relationship: children acquired intelligence from their parents” (ibid).

To make meaning of his data, Galton drew “on the work of the Belgian mathematician Adolph Quetelet, one of the first to apply mathematical models to frequency distributions of human characteristics” (ibid). “Quetelet was struck by the fact that a plot of variation in the frequency of height around a population mean gave a result that conformed exactly to the bell-shaped curve predicted by the Gaussian law of errors. In other words, the variation of a particular anthropometric characteristic [say, height] in a population of individuals is distributed in precisely the same way as the measurement errors made by astronomers that Gauss analyzed” (UVIC). Inspired by the ‘laws of errors’ (now the normal curve) & thinking that it might be applicable to the study of heredity, Galton plotted points noting that his anthropometric data tended to fit [Quetelet’s] ‘normal curve’. He began to estimate the probability of occurrence of given deviations from the norm or average” (ibid).

Galton later wrote that his challenge was that “the primary objects of the Gaussian Law of Errors were exactly opposed, in one sense, to those to which [he] applied them. They were to be got rid of or proved a just allowance for errors. But these errors or deviations were the very things I wanted to preserve & know about” (DSB, V, 266). Gradually, Galton developed his ideas of correlation & regression, “ultimately defining correlation in the 1888 paper: “Two variable organs are said to be co-related when the variation of the one is accompanied on the average by more or less variation of the other, & in the same direction” (Galton, 135). Item #1440

CONDITION: 1888 VOLUME: Complete 8vo. Ex-libris, 2 stamps on the title page, a few within, & no others at all. Handsomely rebound half calf over aged marbled paper boards, 5 gilt-ruled raised bands at the spine; each compartment gilt tooled. Marbled text block. Bright & clean throughout. Near fine. 1890 VOLUME: Complete 8vo. Ex-libris, only a few numbers on the rear of the title page; no others at all. Handsomely rebound in half calf over gilt-ruled marbled paper boards. 5 gilt-ruled raised bands at the spine; each compartment gilt tooled. Light small stain at outer text block, minor impact to some pages. Bright & clean throughout. Near fine.

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Price:
$1,200.00
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