Cooperative learning (also known as "peer learning") is a group-based approach to instruction that establishes positive interdependence among students. Positive interdependence occurs when learning activities are structured such that individuals can attain their goals if (and only if) others in their group also reach their goals. For example, teachers may require a single finished product from a group (goal interdependence), or may offer a reward to the group if everyone achieves above a certain threshold on an end-of-unit quiz or test (reward interdependence). The lesson plan may require that each member of the group be issued different materials that they must share in order to complete the lesson (resource interdependence), or that each member of the group has a different role to play (role interdependence). The group may have their own name (identity interdependence), or each group member may have a unique task that must be completed sequentially, like an assembly line, in order for the lesson to be completed successfully (task interdependence). These varied forms of positive interdependence can be layered upon one another in a single lesson, increasing the incentive for students to cooperate in completing the learning activity.
In addition to positive interdependence, cooperative learning activities should also include techniques to ensure individual accountability; if individual accountability does not exist, then students have less incentive to contribute to the success of the group. Individual accountability could include an end-of-unit test, to be taken individually (with the potential for group rewards as discussed above), or something as simple as a random oral quiz by the teacher as he or she supervises the group work during class. In this scenario, if a randomly chosen member of a group can summarize their work or present their project status, then the group earns points or credit toward a good grade in the lesson (or potentially other rewards, such as snacks, free time, etc.).
Finally, a high-quality cooperative learning lesson should include: (1) Explicit coaching in collaborative skills, which includes (a) setting expectations for group behavior, and (b) monitoring by the teacher to identify and reward examples of such behavior; (2) A high degree of face-to-face interaction, with the group sitting together, facing one another, and isolated to some degree from other groups in the classroom; and, (3) Guided processing of group performance after the lesson is completed, in which the group discusses what they did well, sets targets for improvement in the future, and provides one another with positive reinforcement for behavior that contributed to group success.

The goal of cooperative learning is to establish positive interdependence among students. When positive interdependence is established in group learning situations, the quality of peer interaction improves. Instead of competing with or ignoring one another, students are more likely to promote the success of one another through mutual assistance, emotional support, and the sharing of ideas or resources. These positive social interactions, in turn, encourage greater social acceptance and the development of positive relationships among students and, in educational contexts, promote greater academic motivation and achievement (Johnson & Johnson, 1989, 2005). In fact, research on social interaction suggests that gains in social skills alone are insufficient to reduce social problems among students and encourage more positive peer relations. Only positive interdependence, and the subsequent positive social interactions that arise from it, can motivate youth to re-evaluate previous conclusions regarding the social desirability of others (Bierman, 2004).

Cooperative learning can have positive effects on adolescent bullying, alcohol use, and tobacco use.

Cooperative learning has been found to enhance academic engagement and achievement, as well as interpersonal attraction and social acceptance (Johnson et al., 2014). In a recent meta-analysis of 148 studies representing over 17,000 early adolescents, peer learning was associated with greater achievement and more positive peer relationships as compared to competitive or individualistic instructional approaches (Roseth et al., 2008). The results also revealed that the effects of peer learning on achievement and peer relationships were positively correlated, suggesting that positive change in peer relationships and positive change in achievement tended to occur together.
In addition, in a recent cluster randomized trial using 15 middle schools in Oregon, intervention schools experienced significant reductions in bullying, victimization, perceived stress, and emotional problems, as well as alcohol and tobacco use, as compared to control schools; we also found significantly higher levels of peer relatedness (Van Ryzin & Roseth, 2017; Van Ryzin and Roseth, in press; Van Ryzin & Roseth, in development). The effect sizes for these results were very strong, in the range of .50 to .80 or more, where larger effect sizes indicate that a program is more powerful. To put these effect sizes in context, traditional prevention and social-emotional learning programs have reported effect sizes in the .10 to .20 range in previous research, which suggests that peer-learning can be much more "effective", or more powerful, than these traditional programs. These results suggest that the positive social interactions that occurred during cooperative learning activities were able to significantly improve at-risk students’ experiences in school. By encouraging the development of more positive social relations among students, cooperative learning provided an avenue for socially marginalized students to escape chronic victimization which, in turn, reduced their perceived stress. These collaborative lessons also boosted students’ sense of peer relatedness and reduced emotional problems, suggesting that students perceived the school climate as more friendly and welcoming. We also found significant differences in students’ social networks, such that at-risk students in intervention schools had lower levels of alcohol and tobacco use and bullying perpetration among their friends as compared to at-risk students in control schools.

https://onlinelibrary.wiley.com/doi/full/10.1111/cdev.12981

http://psycnet.apa.org/record/2018-08642-001

http://psycnet.apa.org/record/2008-01984-003