My daughter graduated from a local high school 2 years ago. As a junior she had an English teacher who didn't really teach, but everyday had them independently using Educational videos. The following year the admin cancelled the account saying too many teachers were overusing it. The next year the principal gave that English teacher the Advanced classes! Guess what? He paid for videos himself and kept using it and the AP scores were terrible. Yes there are bad teachers. But a principal who promotes a bad teacher is even worse.