Students who are collaborating are typically working towards a goal, such as completing a project. It’s critical that every person on the team understands what the goal is and what their own personal responsibility is in achieving that goal.
For example, if the project goal is to complete a paper, students need to decide who will focus on researching different topics, who will help write the paper, who will edit it, etc. It could be that several people do the same role, but that should all be decided early in the project to avoid misunderstandings and ensure that project deadlines are met.