Myers, K. and Lee, T. Generating Qualitatively Different Plans through Metatheoretic Biases, in Proceedings of the Sixteenth National Conference on Artificial Intelligence, AAAI Press, 1999.
Most work on AI planning has focused on the development of fully automated methods for generating plans that satisfy user-specified goals. However, users in many domains want the ability to influence the nature of the solutions that are generated. With the objective of fostering increased user participation in the planning process, this paper presents an HTN-based framework for the abductive completion of plan sketches. Within this framework, user-supplied outlines of partial plans (possibly spanning multiple abstraction levels) are interpreted and completed. The processing of plan sketches employs an initial abductive plan recognition phase to formulate candidate sets of intended user goals, followed by a plan refinement stage that generates sketch-compliant final plans for those goals. A prototype sketch-based planner based on this approach has been implemented and applied to a crisis action planning domain.