The Next Generation Science Standards (NGSS) have been imperative for informing many facets of the chemistry education research field, one of which includes the professional development (PD) of high school teachers. While many researchers and practitioners have responded to the NGSS' calls for reform by attending to internal factors that influence…

Teaching chemistry as a practice rather than as a mere collection of facts demands that teachers modify their practices, particularly their approach to formative assessment (FA). In this study, we investigated how teachers' FA practices changed as a result of their participation in a professional development program designed with a Chemical…