What does he mean by "manage expectations?"

Native speaker’s answer
Rebecca
By "manage expectations," he means he wants to prevent any kind of disappointment ahead of time in terms of what can be achieved realistically. More specifically, here he's saying that he's not a trained educator, so they shouldn't expect him to behave completely like one. Ex: We need to manage the expectations of the client by telling them that we can't meet all their requests for tailoring the dress. Ex: Just to manage expectations, this won't all fit into my budget. Ex: We didn't manage her expectations well, and now she's upset we can't stay in a hotel.