My VAM counts the AP scores of 34 students who were in my AP class. I am punished because one parent refused to have her child take the test (the child is in college and doing just fine), and because one student walked out of the test after 30 minutes because his ADD medication ran out two days before and concentration was out of the question. There was no punishment for the proctor who let him leave.
The worst part is the other 124 students had no effect on my evaluation - they were not important to the state of Florida. I could have showed them movies all year, not graded one essay, and given them all A's for occasionally coming to class - or I could have failed them all VAM says they don't matter. They matter to me, they matter to their parents, they matter to my peers, but they don't matter to the politicians, law makers, and corporations.