Another thread put me in mind of this.

How common is it for a therapist to ask for feedback? Both of mine routinely ask (every few sessions or so on average), what kind of job they are doing as my therapist. How would I evaluate their performance, and can they do anything differently/better?

It's not the same as asking "how is therapy going for you?" (they don't ask that because I tell them, regularly) and it doesn't seem to be fishing for compliments, as I am not always complimentary in response but they keep doing it.

I am a little surprised they ask - it's not a question I've ever gotten from a doctor or a teacher, say, though you do fill out surveys on them - so I wondered how common it was?