This is a grant for a conference and encompassing events examining the current research base on the uses of and potential for on-line information technology (OLIT) to enhance and change the ways professional development (PD) is provided to teachers in Grades K-12. The planning for this conference will be largely organized and executed by expert K-12 classroom teachers who are members of the National Academies and California Teacher Advisory Councils. The conference will emphasize the current status of the research literature on uses and influences of OLIT on PD. The conference also will explore current applications of various kinds of information technologies in PD, the potential for emerging technologies to not only restructure but transform PD opportunities, and challenges that remain in using information technologies for these purposes. The issues considered include the following topics: 1) the evidentiary base for understanding and evaluating on-line PD, 2) the current state of on-line PD, 3) assessing the effectiveness of on-line PD, 4) the benefits, costs and economics of on-line PD, and 5) the future of on-line PD. Participants in this conference include classroom teachers, researchers of online PD, school personnel responsible for implementing PD, state legislators and staff from CA House and Senate education committees and representatives from the information technology community who are responsible for developing and marketing hardware and software. The major ideas emanating from the conference will be summarized in an NRC report authored by the NRC planning committee and made available through the National Academies Press.