The PIESC3 (Promoting Inquiry-based Elementary Science through Collaborative Curriculum Co-Construction) project has been funded by the Roy J. Carver Charitable Trust and University of Iowa. The project involves a quasi-experimental, non-randomized two group pre-/post- repeated measures research design, as well as in-depth case studies, over two years to investigate the effectiveness of the PIESC3 professional development program for elementary (K-5) teachers and to learn more about how elementary teachers use existing science curriculum materials to plan and engage in inquiry-based science. This project will be carried out in collaboration with the Davenport Community School District (DCS) and Mississippi Bend Area Education Agency.