This article, the first of a six-article set, introduces a complex study of a science teacher education program whose goal was to graduate teachers who held conceptual change conceptions of teaching science and were disposed to put them into practice. The set of articles includes: (1) an introduction to the theoretical foundations and research methods of the study; (2) the description and analysis of science methods courses at the elementary and secondary levels; (3) the description and analysis of an action research seminar held in conjunction with student teaching; (4) case studies of three prospective elementary teachers; (5) case studies of three prospective secondary teachers; and (6) a summary of the findings of the study and a discussion of its implications. This article presents a framework for considering science teacher education in the context of constructivism, teaching for conceptual change, and reflective practice and action research. It describes the context of the study, including its focus on biology, and outlines the research methods used to address the following research questions: What is the character of key components of the program, viz., methods courses and action research seminar?; How do prospective teachers develop with respect to their practice of teaching over the course of their teacher education program? The answers to these questions allow discussion of broader issues of science teacher education in terms of the following question: What influences do other program components have on the developing practice of prospective teachers? The article finally discusses the data gathering methods including: (1) interviews with prospective teachers on their conceptions of teaching science and conceptions of biological themes; (2) interviews with methods course instructors about the nature of their course (both its content and pedagogy) and their goals and expectations for students; (3) 1 We acknowledge the contributions made to the project by Joan Barrett Roberts, who observed and interviewed prospective elementary teachers.