Roles of design knowledge in knowledge-based systems

Recent research suggests that the abilities of a knowledge-based system (KBS) depend in part on the amount of explicit knowledge it has about the way it is designed. This knowledge is often called design knowledge because it reflects design decisions that a KBS developer makes regarding what ontologies to embody in the system, what solution strategies to apply, what system architecture to use, etc. This paper examines one type of design knowledge pertaining to the structure underlying the solutions a KBS produces. (For example, in medical diagnosis, the output might be just a disease name, but the solution is actually a causal argument that the system implicitly constructs to find out how the disease came about.) We define this type of design knowledge, show how it can be represented, and explain how it can be used in problem solving to make the structure underlying solutions explicit. Subsequently, we also present and illustrate new avenues that the availability and use of the design knowledge discussed open with respect to the ability to build KBSs that possess strong explanation capabilities, are easier to maintain, support knowledge reuse, and offer more robustness in problem solving. (C) 1996 Academic Press Limited