Allow the student to submit final grades.

[Kevin Moore]

Currently the student can keep editing the assignment until the assignment is closed. Allow the student to edit their peer grades but also be able to submit - after which they wont be able to edit the peer grades. This offers the student the chance to 'close off' their work.

[Jeremy Hopkins]

This is handled by the due date and a setting to allow students to submit (but not edit) after the deadline.

Once a student has submitted they cannot edit after the deadline. Once the item is graded by the tutor students cannot edit

This is consistent with the way we approach assignments which is that students can keep working up until the deadline after which their final version is considered final.