The authors analyze some problems met in the attempt to implement an elementary science curriculum involving the use of Elementary Science Study units. The highly organized large scale effort at implementation seemed to have considerable impact at first, but it is now hard to identify lasting effects. The organization of workshops and use of television for inservice teacher education is described, and data are given on the numbers of teachers reached in different areas of the school system over a three year period. A number of reasons for the observed decline in response are suggested, many of them stemming from a loss of interest and commitment on the part of administrators as well as teachers. It is suggested that the initiation of any project from a central office presents problems, and that a central organization may make a more economical impact by providing support requested by schools or individuals. It is also argued that any effort at curriculum implementation requires careful evaluation as a basis for directing rational change. (EB)