Fighting vivi !! :)
Maybe you can add some example from abroad like in Taiwan, I think they're ranked and put in different classes according to their marks ^^
And I think it provoke(?) 2 kind of behavior, like it can give you motivation to work harder in order to get in a higher class rank because your pride just don't allow you to be in the last one lol
And secondly it can just make the students depress lol like "I know I'm a trash, I'm stupid, I can't do it, let's give up"
Well that what I think lol
And I can't really help you, my English isn't good enough to help you out ^^'
Fighting !! :)