Process tracing in clinical judgment.

Abstract

Although much work has been carried out in recent years concerning the description of judgmental processes of human organisms, this has been effected within two distinct schools: the process tracers and mathematical modelers. This paper presents an attempt to reconcile the two approaches by combining the methodological objectivity of the latter with the theoretical orientation of the former. Using data reported by Einhorn (1972) concerning a real judgmental task in medicine, a theoretical model is constructed as a function of situational demands and the limits of human information processing abilities. Suitable to situations where a choice has to be made between several ordinally related alternatives, the model depicts the cognitive process as a multistage discrimination procedure. A methodology is developed to test the theoretical notions. This depicts the cognitive process in the form of a decision tree with separate sets of rules applicable to the various nodes. These models are derived without resort to the use of protocol analysis and are purported to represent the judgmental heuristics of the physicians. The predictive test of cross-validation indicates that the better models developed here perform at a level similar to conventional statistical models of judgment. This result is considered encouraging because the work is clearly only a first, crude attempt; in addition, it shows promise to investigate many substantive issues which mathematical models so far have failed to illuminate.