My mother emailed me the link to this opinion piece on evaluating teachers and the author, who changed careers to enter the teaching profession, makes some very interesting points.  Basically she says that if we're going to evaluate teachers based on testing of students then there should be some considerations made for the teachers:

1. Teachers be assessed based on only those students with 90 percent or higher attendance.
   
2. Teachers be allowed to remove disruptive students from their classroom on a day-to-day basis.
   
3. Students who don't achieve "basic" proficiency in a state test be prohibited from moving forward to the next class in the progression.
   
4. That teachers be assessed on student improvement, not an absolute standard — the so-called value-added assessment. 

My first reaction when I read this, especially numbers two and three, was "O-M-G if a teacher has to ask for that then our education system is truly hosed." And it's not as if the author is saying that teachers are blameless. In fact she also writes this:

Yes, some students are doing poorly because their teachers are terrible. Other students are doing poorly because they simply don't care, their parents don't care, their cognitive abilities aren't up to the task or some vicious combination of factors we haven't figured out — with no regard to teacher quality. No one is eager to discover the size of that second group, so serious testing with teeth will go nowhere.

That's too bad. We need to know how many students are failing because they don't attend class, how many students score "below basic" on the algebra test three years in a row, how many students fail all tests because they read at a fourth-grade level. We need to know if our education rhetoric is a pipe dream instead of an achievable reality blocked by those nasty teachers unions. And, of course, if it turns out that all our problems can be solved by rooting out bad teachers, we need to find that out, too.

Yep.