Introspective Reasoning in a Case-Based Planner

Abstract

trospective reasoning. We can reuse expectations that apply to the planner as a whole for its case-based parts. During the planning process, the introspective reasoner compares the planner's reasoning to its assertions about ideal behavior. When a failure is detected, for instance if the system judges that the retrieved case is not the "best" case in memory, the introspective reasoner considers related assertions to pinpoint the source of the failure and to suggest a solution. In this case our system creates a new index to distinguish the true best case from the bad retrieved case. Determining what information to include in the model and how to structure it are central issues. Birnbaum 's model is a set of high-level assertions applicable to many case-based planners (Birnbaum et al. 1991). While such assertions cover a wide range of failures, they are too general to easily specify causes or repairs for failures. We propose as an alternative a hierarchical model including