What is replication?

PLoS Biol. 2020 Mar 27;18(3):e3000691. doi: 10.1371/journal.pbio.3000691. eCollection 2020 Mar.

Abstract

Credibility of scientific claims is established with evidence for their replicability using new data. According to common understanding, replication is repeating a study's procedure and observing whether the prior finding recurs. This definition is intuitive, easy to apply, and incorrect. We propose that replication is a study for which any outcome would be considered diagnostic evidence about a claim from prior research. This definition reduces emphasis on operational characteristics of the study and increases emphasis on the interpretation of possible outcomes. The purpose of replication is to advance theory by confronting existing understanding with new evidence. Ironically, the value of replication may be strongest when existing understanding is weakest. Successful replication provides evidence of generalizability across the conditions that inevitably differ from the original study; Unsuccessful replication indicates that the reliability of the finding may be more constrained than recognized previously. Defining replication as a confrontation of current theoretical expectations clarifies its important, exciting, and generative role in scientific progress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Data Interpretation, Statistical
  • Humans
  • Reproducibility of Results
  • Research Design / standards*
  • Research Design / statistics & numerical data*
  • Statistics as Topic

Grants and funding

This work was supported by grants from Arnold Ventures, John Templeton Foundation, Templeton World Charity Foundation, and Templeton Religion Trust. The funders had no role in the preparation of the manuscript or the decision to publish.