Stanley Smith Stevens

Stanley Smith Stevens (1906 to 1973) was an American psychologist who founded Harvard's Psycho-Acoustic Laboratory and is credited with the introduction of Stevens's power law. His experimental and theoretical work lay primarily in psychophysics and psychoacoustics. In 1946 he proposed a theory of levels of measurement, defining the nominal, ordinal, interval and ratio scales, which scientists still widely use even though its use in some areas of statistics has been criticized. He edited the 1,400 page Handbook of Experimental Psychology in 1951, was one of the founding organizers of the Psychonomic Society, and played a key role in bringing operational definitions into psychology. Born in Ogden, Utah, he took his doctorate at Harvard and joined its faculty as an instructor in experimental psychology in 1936.