An abductive perspective on clinical reasoning and case formulation.

Clinical reasoning has traditionally been understood in terms of either hypothetico-deductive or Bayesian methods. However, clinical psychology requires an organizing framework that goes beyond the limits of these methods and characterizes the full range of reasoning processes involved in the description, understanding, and formulation of the difficulties presented by clients. In this article, the authors present a framework for clinical reasoning and case formulation that is largely based on a broad abductive theory of scientific method (Haig, 2005b). The abductive theory articulates and combines the processes of phenomena detection and theory construction. Both of these processes are applied to clinical reasoning and case formulation, and a running case example is provided to illustrate the application.