Why does preregistration increase the persuasiveness of evidence? A Bayesian rationalization

The replication crisis has led many researchers to preregister their hypotheses and data analysis plans before collecting data.A widely held view is that preregistration is supposed to limit the extent to which data may influence the hypotheses to be tested.Only if data have no influence an analysis is considered confirmatory. Consequently, many researchers believe that preregistration is only applicable in confirmatory paradigms.In practice, researchers may struggle to preregister their hypotheses because of vague theories that necessitate data-dependent decisions (aka exploration).We argue that preregistration benefits any study on the continuum between confirmatory and exploratory research.To that end, we formalize a general objective of preregistration and demonstrate that exploratory studies also benefit from preregistration.Drawing on Bayesian philosophy of science, we argue that preregistration should primarily aim to reduce uncertainty about the inferential procedure used to derive results.This approach provides a principled justification of preregistration, separating the procedure from the goal of ensuring strictly confirmatory research.We acknowledge that knowing the extent to which a study is exploratory is central, but certainty about the inferential procedure is a prerequisite for persuasive evidence.Finally, we discuss the implications of these insights for the practice of preregistration.