No, but you were responding to a post that sarcastically said, "A teaching job is the gravy train job with biscuit wheels!", and I was continuing along those lines. Plus, like I said, I have nothing against the teachers...it's the teachers unions I have a problem with...and the teachers become whipping posts because of what the unions do. You cannot talk about the education system, their sucesses or lack thereof, without talking about teachers unions.
Why can't you judge teacher performace just like every other person is judged in their job...?...success. If the children are successful and learning what they are supposed to be learning, then the teacher is successful. If not, then the teacher is not successful.
I would think testing the children, and making sure they are able to pass baseline requirements, would be a reasonable way of testing the teacher, wouldn't it? I mean, the kids have to pass baseline requirements to get from one grade to the next...why shouldn't the teachers have some sort of baseline requirements to make it from one year to the next? I don't know, I am just asking the question.
I think that would have to be better than anything based on union criteria...ie, longevity...especially when we have teachers unions who are able to get fired teachers reinstated...with full pay and benefits...even if they are doing things like (for example) viewing porn on school owned computers.
First, understand that teachers more than anyone want a reasonable evaluation system.
Years ago, when teachers were still thought to have professional judgement, we could look back over all we'd asked each student to learn for the year and state that yes, the child had sufficient skills and knowledge to go to the next grade. A knowledgeable administrator would lend support and balance so that the learning was appropriate for kids to show growth. Not any more.
At first glance, testing children might seem to be a reasonable measure. But there are issues.... none which benefit children. Due to the past few decades of mandates such as No Child Left Behind, and IDEA, we now have to test all children at the same level, with variations from state to state. This means that a child with disabilities, a child who is still trying to learn English, psychological issues from being bounced from one family to another, you name it, are all expected to have the same level of achievement at the same chronological point in their lives. There are no tests for some subject areas, so how will those teachers be measured? Our school tests science in November. We have an AB block, which means that when my students are tested, I've seen them in class maybe 20 days, out of 95. They're essentially being evaluated on what they learned the year before. Students are also no longer retained from one grade to the next, so we get children in the 9th grade who read at levels as low as 2nd grade. An accomplished teacher might be able to get that child to gain 2 years, but by standardized tests, the child would still not be meeting standard.
The tests themselves are often invalid. I've worked on various stages of test writing, from standards setting to scoring decisions, in 3 states. The test items are often, because of government mandates and the hiring of private industry to assist, not all that well-constructed. When 8 accomplished science teachers can't agree on how a certain item should be scored because it has ambiguous wording or maybe even contains an error (that was New York, last school year), student scores aren't going to be valid.
Then, there's pure statistics. Many teachers have class sizes of 30+ now, generally considered to be the lowest value of n for which correlational statistical methods are valid. Sampling, however, isn't random. Special ed students are often loaded into a particular teacher's class because that teacher is the most skilled at working with kids who need her/him the most. School elective courses often cause an imbalance of gifted students because of a single advanced course. Some class sections, then, are loaded with high achievers, while other courses have mostly low-achievers.
Student attendance is also an issue. At day 20 this year, the only students failing my classes were those who had 9 or more absences and had made no effort to catch up. I have no clear, convincing evidence that those children are learning, much as I go out of my way when I see them to make sure that they do.
It's actually not that difficult to fire teachers now. It doesn't take a major misconduct episode. Not many administrators are willing to document and counsel and start the process to terminate a teacher. Those who will are worth their weight in gold. I've seen teachers fired, in a fairly short time, for simply being ineffective, and every other teacher in the building was grateful. Yes, the union steps in to make sure that the process is followed, but facts are facts. I've also never worked in a really large city school district, and that's been a conscious choice.
I hope that gave you a better picture of the complexities involved with evaluating teachers, and more importantly, student learning.