History
The index was introduced by Raymond Pearl in 1933. It has remained popular for over seventy years, in large part because of the simplicity of the calculation.
Read more about this topic: Pearl Index
Famous quotes containing the word history:
“It’s a very delicate surgical operation—to cut out the heart without killing the patient. The history of our country, however, is a very tough old patient, and we’ll do the best we can.”
—Dudley Nichols, U.S. screenwriter. Jean Renoir. Sorel (Philip Merivale)
“Systematic philosophical and practical anti-intellectualism such as we are witnessing appears to be something truly novel in the history of human culture.”
—Johan Huizinga (1872–1945)
“We know only a single science, the science of history. One can look at history from two sides and divide it into the history of nature and the history of men. However, the two sides are not to be divided off; as long as men exist the history of nature and the history of men are mutually conditioned.”
—Karl Marx (1818–1883)