How Do We Decide Which of Two Case Formulations Is Correct? Commentary on Westerman and Critchfield et al.

This commentary takes a meta-view of the articles in this module by Westerman (2021a), and by Critchfield, Dobner-Pereira and Stucker (2021a), which offer two overlapping but also different formulations of the same case. It raises the question of whether there is only one true formulation of a clinical case ( correspondence theory ), or whether any one of several would qualify as accurate ( coherence theory ). A third alternative is that the truth-value of a formulation is a function of its ability to predict which therapist interventions will most help the client ( pragmatic theory ). A study is described in which the relative accuracy of two different formulations of the same case was put to the test in predicting which therapist interventions led to client progress. I propose that the current authors compare the pragmatic value of their formulations in a similar manner.