This publication presents a case-based approach to improving teaching practice, offering informal conversations between isolated educators who were brought together to share their problems and air concerns via the use of cases. An introduction offers an overview of professional development cases, explaining what cases are and how to get started. This is followed by eight cases with facilitator notes: (1) "Your Project Will Get a Black Eye!" (Judi Wilson); (2) "Managing Misconceptions" (Linda Hagelin); (3) "What To Do About Rob?" (Diane Demee Benoit); (4) "Through the Eyes of a Participant" (Stephanie Wald); (5) "Girls in Science: Full Partners" (Patricia Kudritzki); (6) "Sink or Swim" (Hector Timourian); (7) "Partnering Is Such Sweet Sorrow" (Jeffrey S. Bryant); and (8) "Critical Moments" (Liesl Chatman). A final section, "Facilitating a Case Discussion" (Judith H. Shulman), discusses: the preparation and process; constructing a case-based professional development curriculum; preparing to lead discussion; dynamics of the group process; leading the discussion; the opening; core of the discussion; closing the discussion; and discussion stages and struggles. (Contains 12 references.) (SM)