This chapter of "Helping Teachers Manage Classrooms" examines the various management techniques required by the different kinds of student groupings associated with different types of classroom activities. These activities are identified in terms of their action structures (specifying who shall do what, when, and to or with whom), their physical milieus (with which the action structures fit more or less well), and their established temporal and spatial frameworks. The activities are also characterized by whether student involvement is self-paced or directed by outside events, whether participants act independently or interdependently, and whether other activities are occurring simultaneously, as well as by the nature of the transitions required between one activity and the next. (Author/PGD)