After spending many years directing professional development programs, Ms. Evans decided to return to the trenches. As a principal trying to lead a large urban high school through substantial change, she learned that even the soundest theories do not always translate smoothly into real-world practice. SMALL SCHOOLS are big. Reformers have long contended -- and growing evidence confirms -- that smaller is better: for instruction, for relationships and community, and for behavior management. Students in small schools are more likely to be known well by faculty members, to be academically challenged, to take intellectual risks, and to engage in authentic learning. New York, Chicago, and Boston are among the cities that have experimented with the creation of new, small schools - - not to mention charter schools, which are almost invariably small. The question isn't whether small schools make a difference, but how to implement them. Dividing a large comprehensive high school into several small schools -- each coexisting productively, side-by-side -- is particularly difficult. Here, as with so many facets of school reform, there is a great divide between the world of university-based theorists, thinkers, and advocates, and the real world of actual school life. Bridging the divide is a challenge I experienced myself when I crossed over to become the principal of a large urban high school and broke it into five small schools. After having taught high school for 17 years, I had spent 15 years at Brown University, much of it directing professional development for the Coalition of Essential Schools and then the Annenberg Institute for School Reform. At Brown, I worked with schools across the country and had constant contact with teachers and principals. I was learning continuously. I had wonderful colleagues. I could consult in a school and then walk away. People appreciated my work, and they told me so. At the same time, I was increasingly jealous of the teachers and principals whose schools I visited. I missed the relationships with adolescents that had been so important to me during my years of teaching. I missed the community of a school. Our work at Brown -- creating critical friends in schools and developing protocols to help teachers look at student work and their own practice -- had some core assumptions about teaching and learning, about leadership, about teacher/teacher and teacher/student/parent relationships, and about the whole process of change. I wanted to test these assumptions for myself. I wondered, Could I help make some of this work in a school? What would it feel like? Would I have the smarts and stamina and sensitivity? Would I run away screaming? And so, after two years of wondering, I took the plunge. The Story In August 1999, I became principal of Cambridge Rindge and Latin School (CRLS). It had 2,000 students and a tremendous achievement gap. As many in the school community acknowledged, it was really two schools: one for the minority poor and the other for the middle-class whites. All members of the school community said that they wanted big change. The school committee, the superintendent, and the teachers said that they wanted change now. The faculty members had studied change for years. They had created teacher, student, parent, and community committees to investigate options and had compiled a large book of proposed initiatives. But they had adopted none. They were ready for some leadership to help make it happen. This is what the faculty members and school administrators told me when I met with some 40 of them before I agreed to take the job. I asked them to describe the strengths and weaknesses of CRLS. Among the former, they cited the school's diversity (it offered something for everyone), its many external partnerships, its standing in the community, its good facilities, and its high per-pupil expenditure. A good list. But the weaknesses they cited were also significant: unequal access to resources across the five houses, a large achievement gap between the strongest and weakest students, institutional racism, clashes of conflicting philosophies between faculty members, much skepticism and cynicism among some groups of teachers, a general lack of accountability, a recent history of divided and unfocused leadership, and a pattern of too much talk and not enough action about school improvement. …