A collaborative assignment is a really solid education tool. What's missing is an explanation of why the author thinks this led to an objective evaluation of w

A collaborative assignment is a really solid education tool. What's missing is an explanation of why the author thinks this led to an objective evaluation of what individual students learned before test day (if he does indeed think that). That is the point of an exam. Imagine if med students could collaborate on their boards. It would pretty well invalidate the purpose.