Managing and leading educational change entails a great degree of complexity and uncertainty and remains a pressing challenge for administrators. This work documents lessons learned from a national study on the concept and development of the Creating Communities of Continuous Inquiry and Improvement project of the Southwest Educational Development Laboratory (SEDL). A review of research by SEDL highlighted the educational benefits of professional learning communities (PLCs), and identified their five defining characteristics, including supportive and shared leadership, shared values and vision, collective learning, supportive conditions, and shared personal practice. To better understand how PLCs evolve, SEDL initiated a 3-year project, including creating a corps of educational professionals ("Co-Developers") willing and able to act as external change agents in schools. Providing resources and scheduling regular meetings, SEDL stimulated deep and ongoing dialogue regarding the essential elements of PLCs. Co-Developers organized a conference with teachers and principals from 20 schools to better promote understanding and cooperation and to overcome apprehension about change among school personnel. The Co-Developers provided valuable data to SEDL through a variety of instruments, including surveys, narratives, visual displays, and reports. While reliable measurements are elusive, SEDL believes the project helped disseminate valuable information about PLCs that will help schools make needed improvements in practice nationwide. (Contains 11 references.) (TEJ)