subpages or top level pages that are required check that all required items on them have been completed. They should check only items that are visible. Otherwise if items are released only to one group will cause people in other groups never to be able to complete the page.
create a subpage
make it required
put an item on it that is released only to one group. Make it required
login as a student not in the group
You'll never be able to get the subpage to show as completed.