Secondary science methods students' thinking on coteaching practice was studied for the development of conscious elements of practical teacher knowledge supporting the use of structured inquiry. Reflective dialogue on practice in an electronic forum was analyzed for elements of formal learning and biography (past and present) that informed thinking on practice. Changes in thinking over time were considered in light of observed practice, including methods students' thinking about inquiry through use of STC curriculum. Three concepts related to experience in learning to teach in this model emerged from the data: (a) movement from cultural acclimation to reflection on inquiry practice, (b) thinking through past educational knowledge and experience, and (c) integrating knowledge and experience in practice. Discussion highlights the integration of formal knowledge, biography, and peripheral participation with development of "knowledge of students" in learning to teach in this model. Implications for preservice teacher education highlight the important aspects of learning to teach in practice in order to begin developing practical teacher knowledge for teaching using structured inquiry.