WHAT IS DEFINED IN OPERATIONAL DEFINITIONS? THE CASE OF OPERANT PSYCHOLOGY

Behavior and Philosophy, 2003 by Ribes-Inesta, Emilio

The differences between Bridgman's and Stevens' conceptions are notorious. On the one hand, Bridgman, in contrast to Stevens, did not advocate a "truth" dimension of propositions depending upon the meaning of concepts. Concepts consisted of words used in doing something, and their referents are precisely such doings, be they physical or linguistic (mental). According to Bridgman, then, it is not necessary to assume an explicit agreement in the form of rules of application that determine the truth value of terms' meanings. From this viewpoint, concepts are not true or false, but rather ambiguous or accurate. The public-private dimension postulated by Stevens in the discrimination acts of denoting and observing results is completely irrelevant. On the other hand, Bridgman, when talking of operational analysis, was not referring to rules or criteria for defining concepts. He was not talking about definitions but rather pointing to the operations (or physical and verbal actions) taking place when the concept is used, so operational analysis for Bridgman was necessarily descriptive, hence a posteriori.

In contrast, Stevens proposed operational definitions as criteria determining the validity of a concept and its application to the extent that it was correlated with a set of procedures and outcomes conceived as operations:

A term denotes something only when there are concrete criteria for its applicability; and a proposition has empirical meaning only when the criteria of its truth or falsity consists of concrete operations which can be performed upon demand. (Stevens, 1963, p. 53)

According to Stevens, an operational definition always consisted of denoting (pointing or a gross physical behavior) and an observed result in the form of a discrimination. These differences between Steven's position and his own were clearly perceived by Bridgman, who disliked the fact that Stevens anchored operationism in basic acts of discrimination and public agreement. As quoted by Hardcastle (1995, p. 417), Bridgman commented to A.F. Bentley that:

[Stevens] has talked with me at length about a couple of his papers before publication and professes to be most enthusiastic for "operational ideas". . .but I simply cannot make him see that his "public science" and "other one" stuff are just plain twisted. I have also discussed with him his "basic act of discrimination without making much impression. . ." (Bridgman to Bentley, 4 May 1936, Percy Bridgman Papers, Harvard University Archives, 4234.10)

Operational analysis for Bridgman was a matter of pragmatics, that is, of how words are used in the context of a theory or a research practice. In contrast, for Stevens, operational analysis was related to the denotation of objects and events, using definitions as criteria for the semantic correspondence between words and objects. While Bridgman thought of operational analysis in terms of pragmatics, Stevens conceived operationism as a matter of semantics.

Operational definitions and the operational analysis of concepts are two different things. Operational definitions consist of the specification of procedures and expected outcomes (procedures used for producing and measuring a phenomenon) as the necessary criteria for establishing that the terms defined are empirically meaningful. In contrast, the operational analysis of concepts involves the a posteriori identification of the physical and/or verbal actions involved in formulating or applying a concept. Thus, operational analysis deals directly with the arguments, rationale, and criteria used in the construction and application of scientific concepts. Concepts are defined according to their use and to the circumstances in which they are applied, including concepts about procedures and operations. Because of this, and in order to avoid confusion regarding the use of the term "operational," operational analysis should be better called a "functional analysis of concepts."