High school improvement is one of the most pressing issues facing American education but little attention has been paid to reform strategies that will improve teaching and learning. Drawing on the expertise of teachers, principals, superintendents, policy makers and researchers, a new paper from the Aspen Institute Program on Education, Transforming High School Teaching and Learning: A District-wide Design by Aspen Senior Fellow Judy Wurtzel, offers both a new framework and concrete suggestions for a new approach to high school improvement across an urban school district. The data on high school student performance and graduation rates make clear that significant increases in student achievement are necessary if all students are to graduate from high school fully prepared for post-secondary education, citizenship, and work. Recent high school reform has focused on organizational aspects of high school, particularly creating a wide variety of smaller schools, smaller learning communities, and alternative learning pathways to meet the needs of young people. However, while smaller schools may create the relationships and conditions that make high quality instruction possible, improved instruction and achievement does not flow directly from them. Given this track record, questions facing the high school reform movement include: -- What will it take to get high school instructional improvement that results in demonstrated increases in student learning? -- What supports do high school teachers need to be successful in improving instruction and from where will they get them? -- What changes affecting the professional role, knowledge, and skills of teachers are needed if reforms are to be successful? Though the ideas represented in the paper are not new -- some school districts and states have implemented some of elements described -- what is useful is the attempt to lay out a fairly comprehensive picture of high school instructional reform and to push the conversation about high school instructional improvement into some new territory. First, the paper builds on work done in many urban districts at the K- 8 level to create systems of "managed instruction," that is, deliberate efforts to align common curriculum and instructional materials, formative and benchmark assessments, extensive professional development, and instructional leaders who support a shared set of instructional practices. Second, the paper suggests how these approaches can be developed and implemented in ways that are both consistent with and reinforcing of a robust vision of teacher professionalism. Third, the paper recognizes the urgency of attracting and retaining a teacher workforce that embraces this new job description for high school teachers and can effect improvements in student learning. Finally, it is useful to note that this paper focuses primarily on the district role in improving high school instruction. This is because it seems increasingly clear that school districts are a key unit for instructional improvement. However, much of what is described here could be initiated or supported by states, by consortia of districts, or by networks of managed schools within or across districts.