The work of this study examines the process of interacting with materials and students while thinking about teaching in order to guide curriculum material designers’ thinking about when and how materials might be helpful for teachers. The study followed a seventh-grade science teacher, who enacted five inquiry-based science units with all 5 of her seventh-grade science classes over a 2-year period. The findings describe the teacher’s interactions with materials written to support teachers learning to teach inquiry science. Findings indicate that this teacher’s ideas developed as she interacted with materials and her students. Information about student ideas, task and idea-specific support, and model teacher language was most helpful.