When researching the topic of covert operations-one of the themes of this volume-we must of course use the same type of rigorous methodology we would use for any other social scientific topic. It is often claimed that replicability is one of the most important features for research. This chapter will explore the potential for research replication in social science and history. Though we will define replicability in greater detail later, the basic idea is simple: if an experiment is conducted properly, then another individual should be able to ask the same research question, re-gather data, undertake the experiment a second time-and come up with essentially the same result as the first experiment. In recent years, social scientists also have sought to establish a replication standard, to enhance the field’s standing as an authentic science. Major figures in the profession1 have called upon researchers to make their raw data available, to facilitate future replication studies; and for researchers to engage in publishable efforts, aimed at replicating the findings of others. Increasingly, social science journals are developing policies that facilitate replication.2