"Research also indicates that peer learning activities typically yield the following results for both tutor and tutee: team-building spirit and more supportive relationships; greater psychological well-being, social competence, communication skills and self-esteem; and higher achievement and greater productivity in terms of enhanced learning outcomes."

Some great collaboration tools for the younger ages

For elementary teachers, the activities look different, but these can be adapted to online courses.

This framework is intriguing to me.