Although practitioners have been asked to make fundamental shifts in their beliefs about reaching all students, the structures of high schools to support that work have not changed appreciably. Teachers teach in isolation, departmental silos lack curricular and instructional coherence across core subject areas, and few teachers share students in…

How many beginning teachers struggle to create new lessons despite the fact that experienced teachers have already designed effective lessons for the same content? Shulman (1987) used the term "collective amnesia" to describe the failure of school leaders to design professional development that included the collection of its best…