The spotlight of educational leadership is on instructional leadership. As pressure for improving student performance in the current standards-based accountability environment swells and test results are increasingly scrutinized, school principals are being urged to focus their efforts on the core business of schooling--teaching and learning. But what does it mean to be an instructional leader? What do principals that are instructional leaders do differently than other principals? How do they spend their time? How do they shape the cultures of their schools? How knowledgeable are they of subject-matter content? How do they work with, and develop, other leaders in their schools? In this study we sought to find answers to these questions by exploring the collective wisdom of several effective instructional leaders. Instructional leadership, not just by the principal but by a wider cast of individuals in both formal and informal leadership roles, can play a central role in shifting the emphasis of school activity more directly onto instructional improvements that lead to enhanced student learning and performance. By contrast, the status quo in most schools is diffuse attention to instruction scattered amidst a variety of environmental, social, and organizational distracters that lead to fragmented and uneven instructional focus. Principals are typically engrossed in organizational care-taking and the responsibility for instructional decisions falls to individual teachers. When individual teachers independently determine the kind and type of instruction in their classrooms, three things tend to occur. First, the instructional culture of the school tends to splinter, as there is no overriding instructional guidance and no coherent glue to tie instruction to a larger whole. Second, the quality of instruction varies widely, as teachers bring different experiences and have different notions of what is good teaching. Third, the content that students receive, even in the same grade, differs from classroom to classroom, as each teacher prioritizes what students ought to know.