[bread_baker]

In California some educators call it the "buddy system" but I'd expect that's just Californian slang.
Some classes in adult schools are open entry (students are allowed to add the class at any time). This is very difficult for the teacher: every week you get one or more new students! My employer uses a modified form of open entry. After about the 9th week, no new students are allowed to add. But still, a lot of students came during the "add" period.
This is why, as your class grows, you need to find out who the newer high students are. You can use them to help the others. Needless to say, with open entry a teacher winds up doing a lot of review. Not just one time of review, but maybe 3, 4, 5...