Putting students in groups isn't the same as designing collaboration. Four short lessons on making group work actually work, then a self-check.
Collaboration is powerful when the task genuinely needs more than one mind — but a group is the wrong tool for work an individual could do alone. Start by asking what the group is for.
Cooperative learning works when the task is built so members need each other to succeed, yet each is answerable for their own part. Those two design principles do most of the heavy lifting.
Most group-work complaints come down to free-riding, unequal effort, and unresolved conflict. Much of this can be designed out before it starts.
Fairness is the part students notice most. A single shared mark for the whole group rewards coasting; the fix is to assess both what the group produced and how each person contributed.