Hi William: Personally, I'm hesitant to let students grade each others paper for reasons of confidentiality and our litigious society and mentality that exists these days. Given an innocent environment, I think this is a practical application of learning through observation (of others work). Important is the planning tool pretesting provides the teacher. Adjustments to curriculum fcan be implemmenteed when it is known where general weaker areas of student performance reside in a class cohort. Regards, Barry