Finding the Good Teachers
The problems with this view are (or at least should be) obvious.
Teaching is a complex multi-faceted web of human relationships. And teachers are human beings, and therefor most of our skill sets are not static state, but plastic and variable under the influence of many variables.
I may be a bad fit for a particular group of students, or the dynamic in the room might be powerfully good. I might have a day, a week, even a year in which I am smoothly, powerfully firing on all cylinders or one in which I am lurching, barely fumbling along on a single stuttering piston. I may be working in a school where everything I could possibly need is at my fingertips, or one where I am thwarted at every turn. Every year, my students emerge from a different moment in history. Every year, I am a few steps further down the path of my own journey.
You know quote from Heraclitus-- "No man ever steps in the same river twice, for it's not the same river and he's not the same man.” That river is a classroom (also, in a classroom, that man is probably a woman, but Heraclitus is a pre-Socratic Greek and as such is not very progressive).
So in a very real sense, trying to separate good teachers from bad is a fool's errand, like taking a 0.5 second sound clip from a recording of an orchestra and using it to evaluate the strength and depth of their entire repertoire.
Every person who ever set foot in a school can talk about the good teachers and the bad teachers CURMUDGUCATION: Finding the Good Teachers: