So it was my understanding that upon integration of Moodle with the Turnitin.com System that users would be able to integrate the gradebooks as well between the two systems. Does anyone else know if this is possible?
I may be wrong, but I think the plugin only allows you to use TurnitIn to check for plagiarism in the submissions of assignments. It integrates (is really a hack) across the entire Moodle system so it is either on for all classes or off for all classes. This allows you to use just the Moodle Gradebook. It doesn't actually integrate the TurnitIn gradebook with Moodle.
We investigated using this plugin as our campus already uses Turnitin, but once we saw how extensive a hack it was to the code, we decided not to for now as we were already in the middle of a massive Moodle and systems upgrade - but that was just where we were at. That doesn't mean I don't recommend using the plugin.
You can always contact Turnitin directly. This gentleman assisted us initially and was helpful:
Marc Goldberg Senior Account Manager iParadigms, LLC - developers of Turnitin email@example.com