Thorngate's postulate of commensurate complexity

Thorngate's postulate of commensurate complexity is the description of a social science phenomenon concerning directions and results of research conducted. Karl E. Weick maintains that research in the field of social psychology can – at a time – achieve only two out of the three meta-theoretical virtues "Generality", "Accuracy" and "Simplicity", and that the third aspect therefore must be neglected in any research. The name of the theorem is derived from the Canadian social psychologist Warren Thorngate of the University of Alberta, whose work is quoted by Weick.

Background

Background to the theorem is the debate of sociologists – mainly Kenneth J. Gergen and Barry R. Schlenker – revolving around the meaning of sociological research. Whilst Schlenker appeared to maintain the position, that context only superficially influenced social behavior, Gergen appeared to maintain that context penetrated everything in social behavior, rendering observations as specific to the very situation observed. Thus, simplifying the discussion, the observation of social behavior would be no more than collecting historical data, since context would never be the same and the results would remain unique. In fact, sociology would be some specialized kind of historical research. Considering this, Thorngate writes

It is impossible for a theory of social behaviour to be simultaneously general, simple or parsimonious, and accurate.

— Warren Thorngate

The statement was confirmed by Gergen:

The more general a simple theory, the less accurate it will be in predicting specifics.

— Kenneth J. Gergen

Weick's Interpretation

Weick describes the model with a clock with the word "General" on the 12 o'clock position, "Accurate" at 4 o'clock and "Simple" at 8 o'clock. According to Weick, research operates in this continuum

• if research attempted to be accurate and simple (6-o'clock research), results would not be generally applicable.
• if research aimed at general and simple (10-o'clock research), results would not be accurate and
• if research general and accurate (2-o'clock research), results would not be simple any more.

Basically, Weick maintains, that there is a trade-off between these three in such a way that only two can be achieved at any given time. Research therefore must operate in different modes to capture reality in sufficient precision and granularity. The theorem therefore becomes descriptive of research and prescriptive of research methology.

Criticism

Though confirming the theorem in general, Fred Dickinson, Carol Blair and Brian L. Ott critizice Weicks use of the word "accurate". Accuracy is hard to achieve, especially if the topic is difficult to qualify, e. g. in researching memory. They suggest replacing the term "accurate" with "interpretive utility".