This reprinted article originally appeared in American Journal of Psychology, 1904, Vol 15
[1], 72-101.(The following abstract of the original article appeared in record 1926-00292-
001.) Attempted to study the scientific correlation between two things. Any correlational
experiment can only be regarded as a sample and presents a certain amount of accidental
deviation from the real general tendency. Accidental deviation can be measured by
the'probable error.'Accidental deviation depends on the number or cases, and on the …

Early in the 20th century, Carl Spearman published several articles in the American Journal
of Psychology on experimental methodology in general and the method of correlation in
particular. They are all-important and seminal works. The following article," The proof and
measurement of association between two things," is important because Spearman
published it as" a commencement at attempting to remedy" a problem in the experimentation
of his day in which" laborious series of experiments are executed and published with the …