A program is described to prepare in‐service elementary school teachers in the subject matter and reasoning skills needed to teach science as a process of inquiry. Included is a procedure for introducing experience‐oriented curricula into the schools. Selected teachers are prepared in a university physics department to serve, under close supervision, as instructors for their colleagues. The program has yielded results with implications for what physics departments should provide for elementary school teachers. Intellectual difficulties encountered by the teachers are discussed that have a bearing not only on successful implementation of school science programs but on physics education in general.