With this grant, Dr. Abir-Am is completing data collection for her ongoing study of the role of research schools in the rise of molecular biology, 1930-1970. She aims to clarify the historical and social processes enabling and constraining transdisciplinary collaboration, innovation and policy in 20th century science. The project revolves around systematic comparisons of four research schools, two in the United States and one each in England and France. Among other things, Dr. Abir-Am is examining the research programs, including both long term theoretical visions and short term empirical strategies. These research programs constitute the sources of conceptual coherence in research schools and of their capacity for adaptation to changes in the disciplinary ecology at large. Comparisons of schools that shared goals but differed in their methodological strategy reveal relations of competition; while comparisons of schools that shared methodological tools but differed in their conceptual goals reveal relations of complementary cooperation. She is also examining the social networks, institutional networks, and policy programs of these research schools. These studies should clarify the interaction within and across research schools, the historiography of molecular biology as a gradual or revolutionary event, and the role of science policy in the development of new disciplines.