We were originally going to use this approach until we discovered that there are backdoors wit this approach. If you view the list through WebDav or Explorer view (essentially the same thing), then the settings above are ignored.

The only way to get this to work properly is to use item level security. We’ve adopted the document library route with an event handler to set permissions dynamically. The student submits their work and the permissions on the document are changed so that lecturers and the student have contribute. Once the lecturer updates the result property, the permissions are then changed so that the student now only has read permissions.