Actually, that's not the premise at all.
The three young, gifted doctors who work for House were hand-picked in an effort to LEARN his diagnostic technique. They are constantly conferring in front of that white board, trying to work things out from all the possibilities/negativities that exist regarding that week's affliction of choice. He questions them regarding their reasoning, tests their powers of deduction, and sometimes gives them a nudge (or an outright shove) in the right direction.
Most of the time he doesn't know what's wrong either... they work it out by disecting EVERYTHING they know about the patient, his/her family, and living environment... often using a trial and error approach depending upon their deductive reasoning.