Engaging in science practices integrated with content facilitates deeper learning of science and is called for by new reforms. Supporting this science learning requires complex teaching that is not common in U.S. classrooms. Given this complexity, beginning elementary teachers need support in learning to engage students in science practices such as constructing evidence-based claims about natural phenomena. A practice-based approach to teacher education, focused on making teaching practice core to professional learning, has been suggested to support beginning teacher development. This approach has shown potential in supporting secondary science teachers’ learning, yet little is known about how it might support preservice elementary teachers’ learning over time. This dissertation addresses this gap by investigating the change in preservice teachers’ teaching practices and knowledge for supporting elementary students in constructing evidence-based claims during a practice-based elementary teacher education program. Using longitudinal qualitative methodology, this study drew on video-records, lesson plans, class assignments, and surveys from one cohort of 54 interns enrolled in a two-year coherent practice-based teacher education program. A subset of five focal interns was followed closely throughout the program. The preservice teachers grew in their ability to support elementary students to construct evidence-based claims incrementally by adding components of the teaching practice over time. Specifically, the teachers typically developed the ability to support students to analyze data earlier than they developed the ability to support students to justify their claims. However, they faced challenges during student teaching in consistently supporting students to construct evidence-based claims. These challenges may be due to the removal of scaffolding in the face of the complexity of fulltime teaching. The findings highlight the potential of a coherent practice-based approach to teacher education. For example, the preservice teachers seemed to draw on courses from across the program in developing their teaching practice. These findings also provide new insights into how teachers learn a teaching practice over time and the factors that influence this learning, such as tools for planning science lessons. The analyses underscore the need for development of and research on tools and scaffolds that might continue to support beginning teaching over time.PhDEducational StudiesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113423/1/aarias_1.pdf