This special issue joins the recent but growing effort to expand knowledge in the learning sciences, by examining the notion of participation in teacher-researcher collaborative design (co-design). Co-design is not just a means to an end; it is a context where professional learning happens. Each of the seven papers describes teacher-researcher…

Intervention research indicates that historical inquiry curricula call for different tasks, materials, and methods of teaching compared to those focused solely on content. Inquiry curricula require teachers to shift from the methods, materials, and assessments to which they are accustomed. As a result, despite intervention research efforts that…