On back-to-school-night at my children’s schools, I was quick to judge their teachers. The poor ones were nervous, robotic and defensive. I was almost always correct in my assessment as my children flourished with the confident, competent teachers, and floundered with the insecure, less competent ones. So if it’s so easy for parents to figure out who’s a good teacher, why should it be so hard for school systems to pass judgment?