Stanley Smith Stevens — American Psychologist born on November 04, 1906, died on January 18, 1973

Stanley Smith Stevens was an American psychologist who founded Harvard's Psycho-Acoustic Laboratory, studying psychoacoustics, and he is credited with the introduction of Stevens' power law. Stevens authored a milestone textbook, the 1400+ page "Handbook of Experimental Psychology". He was also one of the founding organizers of the Psychonomic Society. In 1946 he introduced a theory of levels of measurement widely used by scientists but criticized by statisticians... (wikipedia)

The method of magnitude estimation provided a direct measure of sensation.
A technical survey that systematize, digest, and appraise the mid century state of psychology.
The type of measure used placed constraints on which statistics can be used.