Yes, I think when I've heard about it in the past the different student age groups together were most frequently brought up as the primary cause of benefit. Wh

Yes, I think when I've heard about it in the past the different student age groups together were most frequently brought up as the primary cause of benefit. Where I was wondering if there might be a connection is that a multi-grade classroom also (particularly in small schools) means that a student probably will have the same teacher for multiple years (2-4, in most of the cases I've heard of). I realize that's much less extreme than some of the cases mentioned in the article, but it may still be a secondary source of benefit.