An examination of literature in the field of staff development reveals five models of inservice for principals. The traditional model involves enrolling in courses at colleges and universities. Institutes are short-term specific learning experiences. Competency-based training identifies knowledge and skills needed and focuses on influencing programs. The inservice academy is similar to the traditional model, but an agency provides classes. In networks, individuals from differennt schools and districts link together to share information. Evaluation of these models reveals that adults learn best in situations where they are connected to the process. The Principals' In-Service Program, developed with support of the Institute for Development of Educational Activities, builds on the positive features of the five models. Piloted in 1978-79, it focuses on the needs of local schools and principals. The structure is a collegial support group of 6-10 principals working together with a trained facilitator on long- and short-term problems with a defined agenda. Participants are committed to a full day once a month for 2 years. The group allows principals responsibility for their own learning and development. No implication is meant for superiority of any one of these models. The principals' role is important, and effective inservice education must be a priority for the 1980's. (MD)