Changes sorted by user

Hi! I'm setting up an xwiki instance for use in a school class while the students are working in groups on different projects. The teacher wants to be able to keep an eye on what each individual student is actually contributing, so I'm trying to make a report that shows: 1. a list of all documents to which a student has contributed 1.1 a list of all versions of this document that the student changed/updated Has anyone done anything similar? Right now I'm a bit at a loss, as it seems I have to run thru all the versions of all the docs in the entire xwiki. Might there be a better way? best regards :-) Thomas Drevon