“Basic research” is often used in science policy. It is commonly thought to refer to research that is directed solely toward acquiring new knowledge rather than any more practical objective. Recently, there has been considerable concern about the future of basic research because of purported changes in the nature of knowledge production and increasing pressures on scientists to demonstrate the social and economic benefits of their work. But is there really something special about basic research? The author argues here that (...) “basic research” is a flexible and ambiguous concept that is drawn on by scientists to acquire prestige and resources. She shows that it is used for boundary work and gives examples of the work it does in different situations by drawing on interviews with scientists and policy makers on the category of basic research and the changes they have seen in it over time. (shrink)