This presentation addresses three topics: (1) the assessment of professional learning communities in schools; (2) the design and development of professional learning communities in schools; and (3) the effects of professional learning communities in schools. The purpose of this brief document is to share descriptions, processes, and materials designed as part of the authors' research in the area of professional learning communities (PLCs) and engage participants in reflection and discussion. The paper discusses the design and development of PLCs and provides a 5-year project schedule. In an appendix it presents the five dimensions of a PLC: (1) supportive and shared leadership; (2) shared values and vision; (3) collective learning and application of learning; (4) supportive conditions; and (5) shared personal practice. Other appendices contain a "communities of continuous inquiry and improvement research protocol"; a list of PLC dimensions and critical attributes; a PLC organizer matrix; and a PLC assessment instrument. (Contains 14 references.) (WFA)