I was observed a lot during my two years of teaching. I was observed by principals, Q-COMP coaches, and TFA development staff. I was observed teaching well and teaching poorly. Too many teachers, however, go unobserved for too long. This is bad for them and bad for their students. Simply increasing the number of observations isn't enough, though; the real key is using the right kind of observations.
There are two major categories of teacher observation. We can use technical terms – evaluative observations vs. coaching observations – but really it boils down to “Observations That Can Get You In Trouble” and “Observations That Let You Ask For Help.” For a lot of teachers, and especially veteran teachers, the few observations they get fall only into the former category.
“Observations That Can Get You In Trouble” have their place. Deeply struggling teachers usually can't put together a dog-and-pony show capable of fooling their observer. These kinds of observations, when used competently and in good faith, help administrators identify which teachers need immediate intervention. (They can also be carried out incompetently or used to further personal vendettas, which undermines their value and trustworthiness.) They have a significant role to play, but they shouldn't be the only kind of observation teachers get.
“Observations That Let You Ask For Help,” when done well, are carried out by an impartial coach and kept completely isolated from the administrators and observation processes that can get teachers in trouble. When teachers don't have to worry about getting in trouble, they're more likely to ask for (and take) advice from coaches about how to improve.
When the principal comes to formally observe you, it's natural to try to hide your weaknesses. When the coach comes, assuming they're competent and trustworthy, you can be very straightforward. “I need to get better at checking for understanding mid-lesson,” for example, or, “What's my biggest problem with classroom management?” This is what helps good teachers get better and encourages a professional expectation of reflection and continuous improvement.
Some teachers benefit from observations by master teachers through union-initiated Peer Assistance and Review (PAR) programs. Others get it through the state's Q-COMP program (the "performance pay" part of which is problematic). There are different ways to provide them, but improving the quality of instruction depends on observations that let teachers ask for help rather than pretend to be perfect.