In this paper, we summarize two major components of a research project, Model of Research-based Education (MORE) for Teachers, to build and evaluate a program for rigorous and research-based science teacher preparation at the elementary level. We briefly discuss the research upon which the program is built and two major changes we made in response to the research. We present evidence about the impact of these changes on preservice teacher preparation, attitudes and performance. Our data, a mix of quantitative and qualitative, suggest that students in a reformed sequence of science content and methods significantly improve their beliefs, attitudes and skills in teaching elementary science.