You start by doing a best guess, and actually listening for a correction. For other kinds of requests, you reply with a best guess and ask for confirmation or for clarifying questions.
Right. A good test for a conversational AI is whether it could perform the Abbott & Costello “Who’s on First” sketch with you. It should make assumptions where the characters in the sketch make assumptions, and ask questions borne from confusion where the characters do.
"No, I meant the time in London, Ontario"
"Sure. The time in London, Ontario, is 3:23pm."
You start by doing a best guess, and actually listening for a correction. For other kinds of requests, you reply with a best guess and ask for confirmation or for clarifying questions.
Hard, yes. Not impossible.