Everyone knows what science is…until you ask

What is science? Scientists often assume that we share a general understanding of what science is, yet this assumption has rarely been empirically assessed. We examined scientists' and members of the public's agreement with a range of common conceptualizations of science, including science as a search for truth, a mirror of nature, a free marketplace of competing ideas and others. We found substantial heterogeneity in responses to these conceptualizations, with scientists disagreeing with each other more than the public does. We also found systematic differences in how the public and scientists understand science. Members of the public tended to endorse an idealized view of science, portraying it as a reliable machine for discovering objective truths through well-defined procedures. Scientists, in contrast, were more reserved in their endorsements, often emphasizing the limitations of the scientific method, contingency of scientific results and the roles of improvisation and creativity in scientific practice. This suggests that shared understanding of science cannot be taken for granted. Differences in how we understand science have implications for science practice, education and communication.