School-reform efforts in recent years have stressed, and expanded, the leadership role of the principal. But in the view of many analysts, the task of transforming a school is too complex for one person to accomplish alone. Consequently, a new model of leadership is developing: distributed leadership. This Research Roundup summarizes five documents that discuss different facets of the distributed leadership model. (1) "Investigating School Leadership Practice: A Distributed Perspective" (James P. Spillane, Richard Halverson, and John B. Diamond) provides a coherent theoretical foundation for a distributed view of leadership. (2) "Building a New Structure for School Leadership" (Richard F. Elmore) links distributed leadership to the school's fundamental task of helping students learn. (3) "Co-Principals: A Double Dose of Leadership" (Michael Chirichello) explains how one district has successfully established co-principalships in its elementary schools. (4) "The Bridgeport Story: What Urban School Districts Need to Know About School Leadership Teams" (The Education Alliance) shares a framework and some practical tools for formalizing distributed leadership. (5) "The Bay Area School Reform Collaborative: Building the Capacity to Lead" (Michael Aaron Copland) describes how one school-reform network has succeeded in creating a broader base of leadership in its schools. (WFA)