For this overview of the extent and feasibility of practitioner involvement in professional improvement, practitioners are defined as school-based professionals--teachers, aides, resource specialists, and administrators. Current thought on the need for these individuals to play major roles as decision makers in developing inservice programs is examined through literature reviews and case studies. The first chapter introduces differing philosophies on the nature of inservice and the roles of inservice participants. The rationale for active practitioner participation in inservice programs is discussed in Chapter 2. Chapter 3 offers representative case studies of field-based projects that involved teachers working actively with educational researchers. Chapter 4 surveys practitioner involvement in the delivery and utilization of knowledge. In the fifth chapter, consideration is given to the relationship between school practitioners' level of involvement in decision making and the degree of satisfaction they derive from their jobs. Case studies and analyses are presented of three programs designed to rely upon practitioner involvement in school decision making. The final chapter explores problems that may arise from increased practitioner involvement in professional improvement programs and considers the implications for future trends. A list of references is included. (JD)