One of my sisters is a teacher. She works in an Elementary school with children who have learning and/or behavioral disorders. Tonight she submitted a paper (in a class for her Master's degree) that challenged one of the fundamental tenets held by her professors – universal schooling. Most teachers around here believe that children learn best if you keep them all together and modify their lessons slightly according to ability. They believe that when you split kids into classes, the "dumb kids" know they are in the "dumb class" and are stigmatized for life.
Wrong. That was they way things used to be done at her school. Then they decided to split the kids into classes based on ability, so that the teacher could have the most impact by teaching all the students on one level at the same time. Guess what happened… the test scores for EVERY GROUP increased. She claims in her paper that what makes kids feel dumb is when they are all in a class together and they see students doing much more advanced work and wonder why they aren't doing it. She says kids used to ask her all the time why they weren't doing the same work as the other kids.
Her professor was surprised but receptive to the paper, and posted it anonymously to a class bulletin board. Apparently the response has been somewhat hateful. Imagine that. But I'm proud of her for sticking to her guns, and doing well in her program despite all the liberal jibber-jabber thrown about in her classes.