Published online by Cambridge University Press: 01 January 2022
John Worrall and Nancy Cartwright have both argued that randomized controlled trials (RCTs) are “testing the wrong theory.” They claim that RCTs are designed to test inferences about the causal relationships in the study population, but this does not guarantee a justified inference about the causal relationships in the more diverse population in clinical practice. In this article I argue that the epistemology of theory testing in trials is more complicated than either Worrall’s or Cartwright’s accounts suggest. I illustrate this more complex theoretical structure with case studies in medical theory testing from Alzheimer’s research and anticancer drugs in personalized medicine.
This research received support under the PACEOMICS project, funded by Genome Canada, Genome Quebec, Genome Alberta, and the Canadian Institutes for Health Research (CIHR). I would like to thank Georgina Freeman, Jonathan Kimmelman, Julie Walsh, and the audience at the 2014 Philosophy of Science Association meeting for constructive feedback on the earlier drafts of this manuscript.