Otherwise, take into account just how to assess teacher. Thus, there is more variety of opinions.
The disadvantages can be found, for example, the "friends", ie, evaluate the person who has exhibited work as good or bad you fall, with very little purpose. Anyway I think that this problem is not present because we normally consider to be assessed to the person for their work and not for what it is my friend.
Moreover, this way of evaluating peers think we can discuss with us to reach an agreement as assessed by groups, and this can be an advantage in giving the opinion of each and get different ideas.

