Describe : an explanation facility for an object-based expert system

An important property of an expert system is the ability to explain its actions to its users and developers. This paper discusses the structure and implementation of an explanation system that is used to describe the actions an associated object-based expert system. The construction of an expert system as a collection of objects has significant consequences on the design of an explanation system. These issues and our solution are described. This research was sponsored by the Defense Advanced Research Projects Agency (DOD), ARPA Order No. 4S76, monitored by the Air Force Avionics Laboratory Under Contract F33615-84-K-1520. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Defense Advanced Research Projects Agency or the US Government.