The most frequent form of professional development for teachers--occasional workshops conducted by outside consultants--is widely regarded as ineffective. This document presents findings of a study, conducted by the Indiana Education Policy Center School of Education Office, to examine professional development and its connection to teacher time. Findings indicate that states differ in their approaches to providing time for teachers' professional development. Effective professional development is school-based, uses coaching and other followup procedures, is collaborative, is embedded in teachers' daily lives, and focuses on student learning. Four factors of professional-development initiatives include leadership, resource and policy support, norms of collegiality and experimentation, and adequate time. Nine guidelines for defining the purpose, scheduling, allocation, and use of teacher time are outlined. Options for a system of teacher professional-development time and the components of an ideal system are also described. The final chapter considers several aspects of state policy, including how basic policies might create a reservoir of teacher-development time at each school, how that time might be funded, how the system might be regulated, and how supporting resources might be provided. Four tables are included. The appendix summarizes state-level professional-development policies in Illinois, Kentucky, Michigan, Ohio, Florida, Georgia, and Washington. (LMI)