Bimber presents a theory about the connections between institutional structure and the strategies of experts who participate in politics. He tests this theory by tracing the interaction between Congress and the Office of Technology Assessment (OTA), a recently abolished legislative branch agency created in 1972 to estimate the consequences of new technologies and free Congress from complete dependence on the executive branch for information and policy analysis. In addition, he provides comparative portraits of Congress's remaining support agencies--the Congressional Budget Office, the Congressional Research Office, and the General Accounting Office--and argues that the legislative context for the politics of expertise reveals patterns that have been overlooked in studies of expert knowledge and executive-branch policymaking.