what step would you take to ensure all students contribute to and are accountable for their efforts during collaborative learning activities?
are they talking like i would go around and ask each memeber int he group if the student worked on it. and have the students grade each other?
You could have major problems if you asked each student to comment on and grade other students. Most won't "rat" on their peers.
The teacher needs to constantly monitor each group -- watching, observing, and sometimes commenting and steering the group. The teacher should know who is not cooperating and who is doing most of the work.