The Role of Frame-Based Knowledge Representation in Reasoning

A frame-based representation facility contributes to a knowledge system's A fundamental observation arising from work in artificial intelligence (AI) has been that expertise in a task domain requires substantial knowledge about that domain. Domain knowledge typically has many forms, including descriptive definitions of domain-specific terms (e.g., "power plant," "pump, " "flow," "pressure"), descriptions of individual domain objects and their relationships to each other ('e.g.,"Pl is a pump whose pressure is 230 psi"), and criteria for making decisions (e.g., "If the feedwater pump pressure exceeds 400 psi, then close the pump's input value"). Because of this emphasis on representatbon and domain knowledge, systems that use AI techniqules to achieve expertise are often referred to as knowledge-based systems, or simply as knowledge systems. In order for a knowledge system to use domainspecific knowledge, it must have a language for representing that knowledge. The predicate calculus was appealing because of its very general expressive power and well-defined se-. However, because the language constructs are very fine grained and do not provide adequate facilities for defining more complex constructs, domain experts have difficulty using the predicate calculus or understanding knowledge expressed in it.