When used in conjunction with an actual expert, ChatGPT’s statistical search can be very powerful. It’s essentially performing a statistical search over the space of all diseases it knows about and returning (at a first order approximation) the most reasonable diagnosis. What a doctor should do is to perform tests to rule the suggestions out.

The point isn’t to replace doctors but to empower them. They still need to come up with tests to rule out conditions.

We also have an algorithm for the tests: information gain. If you think of diagnosis like a game of Guess Who, we need to come up with tests which can narrow down the space of possible conditions. (It’s a bit more complicated of course since tests have a margin of error too.)