In this article, the authors argue for a design process in the development of educative curriculum materials that is theoretically and empirically driven. Using a design-based research approach, they describe their design process for incorporating educative features intended to promote teacher learning into existing, high-quality curriculum materials. The process entails analyzing a set of curriculum materials, characterizing students' opportunities to learn through teachers' enactment of the curriculum materials, and assessing students' learning outcomes. The authors then describe ways in which both theoretical perspectives and empirical data guided their design, development, and refinement process for educative features to enhance the curriculum materials, and give examples of the resulting features. Given the current policy environment in which there are heightened expectations for science teaching at the elementary level, the authors argue that testing and refining processes for developing curricular supports for teachers is of paramount importance. While the illustrations provided focus on science curriculum materials and instruction, the authors argue that the principles and processes applied generalize to the design of educative features across subject-matter areas.