The concrete problem

Clinical diagnosis is not simply a test of whether a model can recognize an image or retrieve a fact. A difficult case may contain incomplete symptoms, contradictory test results, an unusual disease, and several plausible explanations. The practical problem is deciding which evidence matters, what to ask next, and how confidently to recommend an action.

That makes diagnosis a sequential decision problem rather than a one-shot classification task. A clinician must separate observations from interpretations, preserve uncertainty, and decide whether the next useful step is another question, a test, a consultation, or immediate treatment. A system that names the correct condition but fails to identify an urgent action can still be unsafe.

Microsoft says its new AI diagnostic system outperformed generalist doctors on hard cases in a study published in Science .…