Operationalization

Operationalization is the scientific practice of operational definition, where even the most basic concepts are defined through the operations by which we measure them. The practice originated in the field of physics with the philosophy of science book The Logic of Modern Physics (1927), by Percy Williams Bridgman, whose methodological position is called operationalism.[7][8]

Bridgman wrote that in the theory of relativity a concept like "duration" can split into multiple different concepts. In refining a physical theory, it may be discovered that what was thought to be one concept is actually two or more distinct concepts. Bridgman proposed that if only operationally defined concepts are used, this will never happen.

Bridgman's theory was criticized because "length" is measured in various ways (e.g. it's impossible to use a measuring rod to measure the distance to the Moon), so "length" logically isn't one concept but many, some concepts requiring knowledge of geometry. Each concept is to be defined by the measuring operation used. Another example is the radius of a sphere, obtaining different values depending on the way it is measured (say, in metres and in millimeters). Bridgman said the concept is defined on the measurement. So the criticism is that there are potentially infinite concepts, each defined by the methods that measured it, such as angle of sighting, day of the solar year, angular subtense of the moon, etc. which were gathered together, some astronomical observations taken over a period of thousands of years.

In the 1930s, Harvard experimental psychologist Edwin Boring and students Stanley Smith Stevens and Douglas McGregor, struggling with the methodological and epistemological problems of defining measurement of psychological phenomena, found a solution in reformulating psychological concepts operationally, as it had been proposed in the field of physics by Harvard colleague Percy Williams Bridgman.[7] This resulted in a series of articles that were published by Stevens and McGregor from 1935, that were widely discussed in the field of psychology and led to the Symposium on operationism in 1945, to which also Bridgman contributed.[7]

The practical 'operational definition' is generally understood as relating to the theoretical definitions that describe reality through the use of theory.

The importance of careful operationalization can perhaps be more clearly seen in the development of General Relativity. Einstein discovered that there were two operational definitions of "mass" being used by scientists: inertial, defined by applying a force and observing the acceleration, from Newton's Second Law of Motion; and gravitational, defined by putting the object on a scale or balance. Previously, no one had paid any attention to the different operations used because they always produced the same results,[9] but the key insight of Einstein was to posit the Principle of Equivalence that the two operations would always produce the same result because they were equivalent at a deep level, and work out the implications of that assumption, which is the General Theory of Relativity. Thus, a breakthrough in science was achieved by disregarding different operational definitions of scientific measurements and realizing that they both described a single theoretical concept. Einstein's disagreement with the operationalist approach was criticized by Bridgman[10] as follows: "Einstein did not carry over into his general relativity theory the lessons and insights he himself has taught us in his special theory." (p. 335).

For example, a researcher may wish to measure the concept "anger." Its presence, and the depth of the emotion, cannot be directly measured by an outside observer because anger is intangible. Rather, other measures are used by outside observers, such as facial expression, choice of vocabulary, loudness and tone of voice; after Damasio, Lesion studies.[12]

If a researcher wants to measure the depth of "anger" in various persons, the most direct operation would be to ask them a question, such as "are you angry", or "how angry are you?". This operation is problematic, however, because it depends upon the definition of the individual. Some people might be subjected to a mild annoyance, and become slightly angry, but describe themselves as "extremely angry," whereas others might be subjected to a severe provocation, and become very angry, but describe themselves as "slightly angry." In addition, in many circumstances it is impractical to ask subjects whether they are angry.

Since one of the measures of anger is loudness, the researcher can operationalize the concept of anger by measuring how loudly the subject speaks compared to his normal tone. However, this must assume that loudness is uniform measure. Some might respond verbally while other might respond physically.

One of the main critics of operationalism in social science argues that "the original goal was to eliminate the subjective mentalistic concepts that had dominated earlier psychological theory and to replace them with a more operationally meaningful account of human behavior. But, as in economics, the supporters ultimately ended up "turning operationalism inside out".[13] "Instead of replacing 'metaphysical' terms such as 'desire' and 'purpose'" they "used it to legitimize them by giving them operational definitions." Thus in psychology, as in economics, the initial, quite radical operationalist ideas eventually came to serve as little more than a "reassurance fetish"[14] for mainstream methodological practice."[15]