Big Brother isn't really watching
It's understandable that teachers dislike lesson observations.
Being closely scrutinized in your workplace would be unappealing to most people. In addition, I think teachers value their independence; they like being left to teach in their own way.
But when the educational success of a large group of students depends on you, it's only right that you get checked up on.
A good teacher who prepares lessons with care has nothing to fear from observations. Actually, they should be enthusiastic. An experienced observer can give you ways to improve that you would not pick up on yourself. The only teachers who should be concerned are the idle or the useless and that's kind of the point.
At my school fully-qualified teachers get observed twice a term (that's less than 1% of their lessons). It's not enough. More observations would create more opportunities for development while leaving less room for bad teachers to hide.
I know such a proposal would be met with groans in every staffroom. Yet teachers should see it as a compliment - observations are an endorsement of the importance of the job teachers do.
