SummaryThis paper describes a “system-building system”, ESSENTIAL-ATTENDING (E-ATTEND-ING), designed to assist in the implementation of expert systems which critique a physician’s plan for patient care. E-ATTENDING has been refined during the implementation of several developmental critiquing systems and may be applied in areas of medical management, patient workup, and differential diagnosis. E-ATTENDING is currently designed to help implement a class of critiquing systems in a subset of possible critiquing domains. It can also be augmented in various ways by interested users to accommodate critiquing domains with more complexity.