This article provides an extended, comprehensive example of how teachers, schools, districts, and external factors (e.g., parental pressure and policy mandates) shape curriculum research in the U.S. It retrospectively examines how three different middle school curriculum units were implemented and scaled-up in a large, diverse school system. The…

To reduce curricular fragmentation in science education, reform recommendations include using common, unifying themes such as scaling to enhance curricular coherence. This study involved 215 participants from five groups (grades 5, 7, 9, and 12, and doctoral students), who completed written assessments and card sort tasks related to their…