Students at the last college where I worked in China, when I questioned them about evaluations of FTs, told me that it wasn't something they took seriously. In fact, as it turns out, they just asked the monitors of each class to write whatever they felt like. Even more interesting is that the assistant to the Dean then falsified the evalutations so that it appeared as if all the students had taken part in it. My students were quite irritated by this when they found out the truth. They had rightly perceived from the get go that it was all a game; however, they didn't appreciate having words put in their mouths that were never there in the first place.

Therefore, evalutations can't be taken too seriously. Whether they are glowing evaluations or not, they simply reflect the opinion of a few people. (Having said that, though, I have taught at a few schools where we, the FTs, handed out evaluation forms to the students and we could see that they were putting there names on the forms that had relevant questions in terms of our teaching ability and etc.)

Observations are pretty much cut from the same cloth. You could be at your best on the day you are observed and it still wouldn't make much of a difference if the observer has preconceived notions about your teaching ability, or for some reason simply hasn't taken much of a shine to you. Moreover, it's all part of the game; if the observer paints a poor picture of your abilities, you will simply be asked to do your best to improve and then asked to sign a new contract.

Play the game by their rules and you could teach in China until your simply too old to cut the mustard, regardless what evaluations or observations reveal about your teaching ability.