This study investigated the impact of a comprehensive professional development project focused on inquiry-based integrated lessons to improve the quality of science instruction for elementary teachers. Eleven teachers from three Northwest school districts participated in this quasi-experimental design study. A focus of the study was to investigate the intricate relationship between four components of a professional development model: the professional development intervention, teacher practice, student outcomes, and teachers’ self-efficacy for science instruction. Five different measures were used both before and after the intervention: The Local Systemic Change Observation Protocol, a content knowledge assessment, a self-efficacy survey, a student content test, and a student science attitude survey. In an effort to triangulate data, a reflective digital journal was kept by each teacher throughout the project. Results indicate that teachers involved in the professional development intervention experienced statistically significant growth in lesson quality and self-efficacy for teaching science, thus impacting their practice and their students
