This paper addresses, and seeks to correct, some frequent misunderstandings concerning the claim that science is socially constructed. It describes several features of scientific inquiry that have been usefully illuminated by constructivist studies of science, including the mundane or tacit skills involved in research, the social relationships in scientific laboratories, the causes of scientific controversy, and the interconnection of science and culture. Social construction, the paper argues, should be seen not as an alternative to but an enhancement of scientists’ own professional understanding of how science is done. The richer, more finely textured accounts of scientific practice that the constructivist approach provides are potentially of great relevance to public policy.