MYCIN was an early expert system developed in 1976 at Stanford University to advise physicians on bacterial infections and appropriate treatment. It aimed to help non-expert physicians who had incomplete evidence and needed to make timely decisions. MYCIN was found to achieve higher accuracy rates than human doctors in diagnosing and recommending treatment for bacterial infections, establishing expert systems as a competent medical tool. However, MYCIN was never widely implemented in clinical use due to legal liability concerns if it provided incorrect diagnoses and the risk that doctors would rely too heavily on its recommendations instead of consulting experts.