Differentiation is simply a teacher attending to the learning needs of a particular student or small group of students, rather than teaching a class as though all individuals in it were basically alike. This book explores in 10 chapters how school leaders can develop responsive, personalized, and differentiated classrooms: (1) "Understanding Differentiated Instruction: Building a Foundation for Leadership"; (2) "Reasons for Optimism About Differentiation: Its Basis in Theory and Research"; (3) "Lessons from the Literature of Change: What Leaders for Differentiation Need to Know"; (4) "Establishing Conditions to Initiate Systemic Change"; (5) "Practical Strategies for Implementing a Differentiation Growth Plan"; (6) "Staff Development That Supports Differentiation"; (7)"Continuation of System Growth Toward Differentiation"; (8) "Communicating with Parents and the Public About Differentiation"; (9) "Growth Toward Differentiation in Context: A Case Study of Change in Process"; and (10) "Planning for the 'What' and the 'How' of Differentiation." An appendix contains six documents, including guides and questionnaires, that may be useful to school leaders as they plan for and support growth toward more academically responsive classrooms. (Contains 80 references.) (RT)