What if they started the year at the 5th grade level? And how many students matter? All of them? Is 90% good enough? What if all of them were reading above grade level to start the year? What tool are you using to measure that reading level? What if students don't try on the test, because it doesn't affect them directly - or worse, they tank purposely because they know it affects their teacher's pay?
What about art classes? What's the difference between 7th grade art skills and 8th grade art skills? And who is doing all of these performance reviews? Principals are busy with students much of the day, communicating with parents, engaging in the business of the school. How are they to do performance reviews? And when?
Shouldn't one wait until the END of the year to test students - if teachers are to be rated based on growth? Michigan tests in early April, a full 2 months before school ends. Should students' growth be prorated then?
Nebulous, vague terms like "performance standards" and "annual review" mean absolutely f'n nothing until you put details behind the terms. The problem, of course, is that the "products" in education are people, not objects.
Which is why the McDonald's manager can more easily give a performance rating to a fry cook than one can to a teacher. Fries don't have crappy homes, inconsistent support, motivation issues... or free will.
Try again.