Implications of Recent Work in Philosophy of Science for the Role of Operational Definition in Psychology

Abstract

Philosophers of science have recently shown that not only extreme operationism but any operationist position faces very serious difficulties. Psychology has tended to take for granted that only one kind of terms, terms in the “data language” or “observation terms,” have direct empirical meaning, and that the empirical meaning of all other terms is given by their operational definitions. Strong arguments have now been put forth indicating both that such “observation terms” are impossible to distinguish and that there are other indirect sources of empirical meaning besides operational definitions. If these arguments are correct, two conclusions follow: (a) It can no longer be maintained that psychological concepts must be “reconstructed” in terms of operational definitions; and (b) There is no longer any basis for failing to require the justification of operational definitions used in psychological research.