Evaluating psychodiagnostic decisions

Rationale   Several frameworks can be used to evaluate decision making. These may relate to different aspects of the decision‐making process, or concern the decision outcome. Evaluations of psychodiagnostic decisions have shown diagnosticians to be poor decision makers. In this essay we argue that this finding results from the evaluation of only one part of the diagnostic process. Method  We put forward that evaluations are typically carried out by comparing clinicians’ behaviour to one of several normative models, for example hypothetico‐deductive reasoning. These models make strong assumptions about human reasoning capabilities, which make it almost impossible for people to measure up to them. The subsequent two parts of the psychodiagnostic process (causal explanation and treatment decisions), are typically not included in these evaluation studies. Treatment decisions are evaluated in effectiveness studies; that is, they are evaluated in terms of their outcomes, not in terms of the diagnosticians’ decision processes. Psychodiagnosticians’ causal explanation has hardly ever been the subject of evaluation. We argue that in order to achieve clinical excellence, this part of the psychodiagnostic process should also be well understood. Results and Conclusions  In this essay we first describe evaluation of psychodiagnostic decision making. We then propose a framework to describe causal explanation, that is, a situation assessment in terms of a causal schema or a story or script. We identify and discuss the tools available for evaluating this part of the psychodiagnostic process.