Metatheoretic Plan Summarization and Comparison

We describe a domain-independent framework for plan summarization and comparison that can help a human understand both key strategic elements of an individual plan and important differences among plans. Our approach is grounded in a domain metatheory, which specifies important semantic properties of tasks, instances and planning methods. The metatheory provides a semantic framework for guiding the choice and description of concepts used in summarizing and comparing plans, thus avoiding syntactic constructs whose meaning or import is unclear. We define three capabilities grounded in the metatheoretic approach: (a) summarization of an individual plan, (b) comparison of pairs of plans, and (c) analysis of a collection of plans. Application of these capabilities within a rich application domain shows their value in facilitating user understandability of complex plans.