Abstract

Most current Knowledge Acquisition(KA) approaches provide tools that are specifically tailored to a predefined library of problem-solving methods (Klinker et al. 1991; Puerta et al. 1992). These tools support users in populating knowledge bases (KBs) with domain-specific knowledge that the methods need. However, these tools do not support users in modifying the individual problem-solving methods beyond substituting one method for another one in the library. Hence, KA tools that support users in making a wider range of changes to problem-solving methods are needed.
We are currently developing EXPECT(Gil 1994), a tool that supports users in making a broad range of changes to knowledge-based systems (KBSs), including changes to problem-solving methods. EXPECT represents problem-solving methods explicitly, and its KA tool reasons about them to guide KA. Problem solving knowledge in EXPECT is structured in smallsize methods. A method is a procedure for achieving a problem-solving goal. This procedure may include subgoals which are invocations to other methods. Methods goals have parameters that are bound to the values of the parameters of the subgoals that call them. Modifications to problem-solving methods rarely consist of a single change. Instead, they require a sequence of related changes to different pieces of knowledge. Failing to perform the complete sequence may leave the KB in an incoherent state. For example, suppose the user wants to add a new parameter to a method. This modification requires several individual modifications to different methods:(1) adding the declaration of the new parameter;(2) using …

Date

July 1, 1997

Authors

Marcel Tallis, Yolanda Gil

Journal

Knowledge Acquisition

Volume

3

Issue

2

Pages

117-135