Three studies were made of the implementation of the Australian Science Education Project (ASEP) materials in secondary classes in Victoria, Australia. The materials were designed to facilitate a more individualized approach to the learning of science. The first implementation study sought the perceptions of teachers, the second analyzed student reactions, and the third consisted of a case study of two groups of students using ASEP materials. Teachers reported desirable changes in the way students spent their time but noted increasing problems in performing their teaching tasks. They felt that a more teacher centered role needed to be taken when ASEP materials were used. The studies of student reactions focused on actual time on task and perceptions of the learning environment. A consistent pattern of time use emerged, with fifty-one percent of time spent on task. This is generally accepted as an expected outcome by teachers unless specific steps are taken to increase the proportion of time spent on work-oriented activities. Although there were some positive changes in student perceptions during their use of ASEP materials, there was an overall decrease in their satisfaction with the materials. The quality of student work was clearly seen by teachers as unsatisfactory. While students reported less difficulty with school science when using ASEP materials, teachers expressed concerns about superficial treatment of topics by students. It is concluded that ASEP remains an example of an investment of time and resources on materials development not matched by an investment in subsequent research and development in teacher education and teacher support. (JD)