Important Dates

Fourth ICAPS Workshop on Hierarchical Planning (HPlan)

    The motivation for using hierarchical planning formalisms is manifold. It ranges from an explicit and predefined guidance of the plan generation process and the ability to represent complex problem solving and behavior patterns to the option of having different abstraction layers when communicating with a human user or when planning co-operatively. The best-known formalism in the field is Hierarchical Task Network (HTN) planning. In addition, there are several other hierarchical planning formalisms, e.g., hybrid planning (incorporating aspects from POCL planning), Hierarchical Goal Network (HGN) planning (incorporating a hierarchy on goals), or formalisms that combine task hierarchies with timeline planning (e.g. ANML). Hierarchies induce fundamental differences from classical planning, creating distinct computational properties and requiring separate algorithms from non-hierarchical planners. Many of these aspects of hierarchical planning are still unexplored. Thus, we encourage any contribution, independent of the underlying hierarchical planning formalism, and want to provide a forum for researchers to discuss the various aspects of hierarchical planning.

    Topics of interests include but are not limited to:

    • Theoretical foundations, e.g., complexity results
    • Heuristics, search, and other solving techniques for plan generation
    • Techniques and foundations for providing modeling support
    • Challenges and lessons learned from modeling systems (using hierarchical models)
    • Applications of hierarchical planning
    • Plan explanation for hierarchical models
    • Hierarchical plan repair techniques
    • Techniques for verifying solutions of hierarchical planning problems

    Workshop Format and Submission Details

    We aim at having a hybrid format (both physical and simultaneously online) so that authors can also present their work if they cannot attend ICAPS 2021, though we encourage attendance in person.

    The formatting guidelines (author kit, etc.) are the same as for ICAPS 2021. Authors may submit long papers (up to 8 pages plus up to one page of references) or short papers (up to 4 pages plus up to one page of references). The purpose of short papers is to encourage publications of more preliminary results. In case of acceptance, the full 5, resp. 9, pages can be used for the paper, e.g. to address the reviewers' comments.

    Like at the main conference, there will be a high quality double-blind review process against the standard ICAPS criteria of significance, soundness, scholarship, clarity, and reproducibility. However, submissions may be less evolved than at the main conference.

    In addition to standard technical papers we also encourage the submission of position/challenge papers (which have to be short papers). The purpose of position/challenge papers is to report on or to make aware of interesting/important problems in Hierarchical Planning. The main idea behind this category is to make aware of an interesting problem and to encourage discussion at the workshop -- not to present some significant contribution.

    Important Dates

    The submission dates will be announced in time, but we assume a submission around the end of March.

    We encourage the submission of papers that are, at the time of submission, currently under review at IJCAI 2021 and/or SoCS 2021. In case such a double submission gets both accepted at IJCAI/SoCS and at the workshop, the proceedings will include a link to the paper at the other conference (so formally it will not be part of the proceedings), but the authors can still present the paper at the workshop.

    Organizing Committee