This book is a general report on aspects of group processes in elementary and secondary schools with reference to appropriate research. Group processes are defined as changes in the social unit known as the group that take place over a period of time; the expected changes occur in three domains--cognitive, psychomotor, and affective. The book covers the informal structure and functioning of the group, the teacher and the group (with discussions of leader behavior), and group influences and individual learning. Basic ideas for teacher use are suggested, and there is a brief bibliography. (JA)