Today I was helping a friend out with a math problem, some algebra, and I hit a thick patch of rust in my brain. After scratching my head a bit and then working through the problem, I decided to consult with my personal math expert, my dad. Despite having been taught most of the math he ever learned before 1964, my father has amazingly retained all of that knowledge and is happy to share it with anyone who bothers to ask for help. So after a quick call home, some description of the exponents in the equations and a little jotting down in my notebook, he had explained everything I in turn hoped to explain to my friend.
After hanging up the phone, I realized that this is one of the big inequalities that exist in our current educational system. It doesn't matter how much value-added-effectiveness my teachers in school were shown to have by complex and inaccurate algorithms. It's irrelevant how much test-prep a teacher might have run us through before an important exam. I and many others, who are fortunate enough to have a parent who can teach and explain the things that are taught in school, learned the concepts we did, and got the grades we did because of the knowledge that our parents were able to share with us.
I had great teachers growing up. Most of them would probably score very well on the myriad teacher evaluation schemes springing up around America. Most of them taught a lot of students who, like me, had parents with significant education, and would end up doing well on tests. But it doesn't matter how great those teachers were because however much time I spent sitting in my 9th grade math class with Mr. Bell, I spent a lot more time learning from my dad. I learned what math I know from sitting at the kitchen table doing homework with my dad within shouting distance if I got stuck on a problem I didn't understand.
Obviously, there will always be disparities in how much every child's parents know about a particular subject, and that will always be an advantage that the children of educated parents, who take the time to help them, will have over their peers. That's fine, there's nothing (sensible) that can be done about that, but it is quite another thing to ignore that fact and judge teachers solely on the successes, or failures, of their students.