These digests provide information for educators about the nature of cooperation and how cooperative principles can be used to restructure classrooms, administrative hierarchies, and work relationships of all types. Digest 1 describes the competitive, individual, and cooperative interaction patterns and examines the impact of cooperative learning experiences on achievement levels. Digest 2 presents one teacher's experiences with traditional student grouping; differentiates traditional and cooperative learning groups; recommends the number of students in a cooperative depending upon the teacher's intent; examines group composition; and discusses random and structured grouping as two ways to arrange cooperative groups. Digest 3 discusses positive interdependence and individual accountability as elements differentiating cooperative learning from group work and examines simultaneity, proximity, and social skills as important elements of cooperative learning. Digest 4 further examines nine types of positive interdependence and how teachers can incorporate them into cooperative learning activities: (1) goal interdependence; (2) resource interdependence; (3) role interdependence; (4) identity interdependence; (5) task interdependence; (6) reward interdependence; (7) outside enemy interdependence; (8) environmental interdependence; and (9) fantasy interdependence. (KDFB)