On the Accuracy of Replication Failure Rates

A prominent approach to studying the replication crisis has been to conduct replications of several different scientific findings as part of the same research effort. The reported proportion of findings that these programs determined failed to replicate have become important statistics in the replication crisis. However, these "failure rates" are based on decisions about whether individual studies replicated, which are themselves subject to statistical uncertainty. In this article, we examine how that uncertainty impacts the accuracy of reported failure rates and find that the reported failure rates can be substantially biased and highly variable. Indeed, very high or very low failure rates could arise from chance alone.