This study was designed to investigate the impact and implementation of ASEP in Victorian secondary schools. ASEP was described as a complex curriculum project facilitating a reconsideration of the classroom organization for the teaching of secondary science. The materials were introduced at a time when schools are being encouraged to accept greater responsibility for curriculum. A series of research questions were developed from an analysis of the literature on curriculum innovation and a review of the ASEP materials. These questions provided the focus for a study which was organized in two distinct phases. The first phase involved a questionnaire survey of 151 science teachers from 121 high schools. The second phase involved an investigation of 23 teachers implementing an ASEP unit. The data gathering extended over one year with the implementation phase requiring a monitoring of classrooms for up to seven weeks. A wide variety of data gathering strategies were employed (eg questionnaires, interviews, classroom observations) and the data analysis techniques used included factor analyses and ANOVA and ANCOVA models. All findings were interpreted and discussed in a period of rapid development of ideas in areas of curriculum innovation, implementation and teacher education related to curriculum development.