To identify factors affecting the implementation of new science curricula a questionnaire survey of principals and teachers in California and Nevada secondary schools was used to select a sample of schools using Chemical Education Materials Study (CHEM Study) or Introductory Physical Science (IPS). Interview data collected when these 67 schools were visited supplemented questionnaire data. The results indicated that effective implementation of new programs required the provision of assistance and support to school curriculum development personnel in terms of research and resource materials for curricular decision making, a total curriculum plan, appropriate inservice education, and continual curriculum evaluation and revision. A list of school procedures that help overcome specific problems, such as student deficiencies in mathematics or reading and inadequate teacher preparation time, is included. Tables summarize questionnaire data on teacher preparation, teachers' reports of implementation problems and their ranking of teacher needs for successful curriculum adoption. These tables are provided for IPS courses, biological sciences Curriculum Study (BSCS) Biology, CHEM Study, and Physical Science Study Committee (PSSC) Physics. Appendices provide copies of questionnaires and interview schedules used, and provide data on the school districts using the new curricula materials. (AL)