Persuaded that quality teaching is the most important way to raise student achievement, the new leadership of the San Diego, California schools initiated a focused set of instructional reforms to "jolt" the system from bottom to top beginning in 1998. Interviews of educators at all levels of the system, district-wide surveys of principals and teachers, and case studies of three middle schools developed over a five-year period examine the interaction between the "micro" (classroom) changes and "macro" (top-down) policies that characterize San Diego's efforts. The study, summarized here, examined certain age-old tensions when top-down meets bottom-up: (1) How strategies address both systemwide needs (including equity and quality) and local differences between (and within) schools or districts. These strategies include differences among grade levels, subject matters, teacher distribution and local labor markets, and considerations of income and knowledge distribution, among others, particularly as these affect the capacity or will to implement state and/or district policy; (2) How agents maintain a commitment to locally defined goals in the face of district or state policies aimed at crosscutting, externally defined goals that seem to require redirection; and (3) How policies and agents seeking to redefine professionalism as collective responsibility for knowledge-based practice rather than individual autonomy attend to questions of principled knowledge, local context, and shared authority. The study concludes that, while the path has been rocky, in many respects the district's theory of learning, theory of teaching, and theory of change are succeeding, although to different extents in different parts of the system.