 The regress poses a problem about how to choose between these interpretations, a problem which threatens the epistemic value of replication studies if there are no rational grounds for choosing in a particular way. Determining whether one experiment is a proper replication of another is complicated by the facts that scientific writing conventions often omit precise details of experimental methodology (Collins 2016), and, furthermore, much of the knowledge that scientists require to execute experiments is tacit and “cannot be fully explicated or absolutely established” (Collins 1985: 73).