One sometimes wonders if good teaching is anything like pornography. As the good Supreme Court Justice said many years ago, I can't define it but I know it when I see it. Most kids can tell you they know good teaching when they experience it and so can their parents.
How much does good teaching have to do with test scores-- not much. Sure good teachers often, but not always, have students with good standardized test scores. But it is also true that some of the finest teachers also have students with terrible test scores.
Good teaching is first of all caring. It is being knowledgeable of the content and knowing how to convey that content in as many ways as it takes until the student learns it. Good teaching is also taking time to notice that a child is upset and needs some listening. Good teaching is making the content meaningful to the child's world.
Most people know these things. And if they do why the huge emphasis on test scores. First of all test scores are measurable. Americans have a great fascination with things that can be measured. Even though we know full well that the most important things in our lives do not have a calculus. So we decide that if the test scores are good, good teaching must have happened and if they are not good, then good teaching didn't happen. That is an over simplification in the extreme. There are just too many other variable effecting good test scores besides good teaching.
Unions don't like it when test scores are used to measure good teaching. But they dislike using test scores for this purpose for all the wrong reasons. Fifty years ago teachers' associations were professional organizations that cared about the profession and the children being served. Today unions only care about protecting the health and welfare of the teachers they represent. They are not different from any blue collar union and that is all the greater loss for the profession and for the children. So unions don't like test scores because they want to protect their membership, even members who do not deserve to be in the profession.
It is most unfortunate that we educators do not have a professional association today because we are in desperate need of coming up with a model to evaluate good teaching and that model needs to be developed by educators who understand the process of education. It should not be done by politicians or union organizers.