In v1.9 there is going to be some kind of structure-controlled permissions, as far as I read some days ago in a forums answer by Damian to somebody's (?) question.... Also could be the catgory-controlled permissions, that somebody suggested in the forums (or users list) longer ago... (sorry, don't have the links to those posts)
P.S. By the way, Cicada, do you know the info at: http://tikiwiki.org/tiki-index.php?page=LearningManagementSystemDev
It would be nice to read a bit more about what are you using (or planning to use) the Wiki for in you uni case...