“You can’t be a police officer, so don’t try. That would suck anyway. If you make each part of the group a separate thing that requires cohesion to the other parts, then it will work best.”
“Get over it. You can’t.
“If you mean group in-class work, some students will always do more.
“If you mean out-of-class work, you’ll need a way of asking them to tell you what they contributed.
“The bottom line is that students participate in different ways, and sometimes they don’t participate, but you can’t always know that.
“Finally, read Robert Brooke’s “Underlife and Writing Instruction,” CCC 38.2 (May 1987): 141-153. It’s old but good.”