Implementation of an Agent-centric Planning of Complex Events as Objects of Pedagogical Experiences in Virtual World

  • Received : 2015.11.10
  • Accepted : 2016.01.12
  • Published : 2016.03.28


An agent-centric event planning method is proposed for providing pedagogical experiences in an immersed environment. Two-level planning is required at in a macro-level (i.e., inter-event level) and an intra-event level to provide realistic experiences with the objective of learning declarative knowledge. The inter-event (horizontal) planning is based on search, while intra-event (vertical) planning is based on hierarchical decomposition. The horizontal search is dictated by several realistic types of association between events besides the conventional causality. The resulting schematic plan is further augmented by conditions associated with those agents cast into the roles of the events identified in the plan. Rather than following a main story plot, all the events potentially relevant to accomplishing an initial goal are derived in the final result of our planning. These derived events may progress concurrently or digress toward a new main goal replacing the current goal or event, and the plan could be merged or fragmented according to their respective lead agents' intentions and other conditions. The macro-level coherence across interconnected events is established via their common background world existing a priori. As the pivotal source of event concurrency and intricacy, agents are modeled to not only be autonomous but also independent, i.e., entities with their own beliefs and goals (and subsequent plans) in their respective parts of the world. Additional problems our method addresses for augmenting pedagogical experiences include casting of agents into roles based on their availability, subcontracting of subsidiary events, and failure of multi-agent event entailing fragmentation of a plan. The described planning method was demonstrated by monitoring implementation.


Situated Learning;Cyber-world;Pedagogical Experience;Diversity of Situations;Event Planning;Agent;Simulation


  1. J. Murray and S Malone, "The structure of advanced multimedia learning environments: Reconfiguring space, time story, and text," ITS '92, Montreal, Canada, 1992.
  2. E. Ohmaye, Simulation-based language learning, Northwestern Univ., Ph.D dissertation, 1992.
  3. C. Miller, J. Lehman, and K. Koedinger, “Goals and learning in microworlds,” Cognitive Science, vol. 23, no. 3, 1999, pp. 305-336.
  4. R. E. Fikes and N. J. Nilsson, “STRIPS: A new approach to the application of theorem proving to problem solving,” Artificial Intelligence, vol. 2, no. 3-4, 1971, pp. 189-208.
  5. M. Georgeff and A. Lansky, "Reactive reasoning and planning," Proc. 6th Nat'l Conf. on Artificial Intelligence, Seattle, WA, 1987.
  6. D. Nau, “Current trends in automated planning,” AI Magazine, vol. 28, no. 4, 2007, pp. 43-58.
  7. K. Erol, Hierarchical Task Network Planning: Formalization, Analysis, and Implementation, Dissertation, Univ. of Maryland, 1996.
  8. F. Charles, M. Lozano, S. J. Mead, A. F. Bisquerra, and M. Cavazzal, "Planning formalisms and authoring in interactive storytelling," Proceedings of TIDSE. vol. 3. 2003.
  9. W. Johnson, J. Rickel, and J. Lester, “Animated pedagogical agents: Face-to-face interaction in interactive learning environments,” International Journal of Artificial Intelligence in Education, vol. 11, 2000, pp.47-78.
  10. J. Porteous, M. O. Cavazza, and F. Charles, “Applying planning to interactive storytelling: Narrative control using state constraints,” ACM Trans. on Intelligent Systems and Technology, vol. 1, no.2, Nov. 2010.
  11. A. Shoulson, M. Gilbert, M. Kapadia, and N. Badler, "An Event-Centric Planning Approach for Dynamic Real-Time Narrative," MIG '13, Dublin, Ireland, Nov. 2013.
  12. J. Bates, B. Loyall, and W. Reilly, "An architecture for action, emotion, and social behavior," Lecture Notes in Computer Science, Vol. 830, 1994, pp. 55-68.
  13. S. Marsella, W. Johnson and C. LaBore, "Interactive pedagogical drama for health interventions," Proc. of AIED 2003, Australia, 2003.
  14. A. Zook, S. Lee-Urban, M. O. Riedl, H. K. Holden, R. A. Sottilare, and K. W. Brawner, "Automated scenario generation: toward tailored and optimized military training in virtual environments," Proceedings of the International Conference on the Foundations of Digital Games, ACM, 2012.
  15. K. Koedinger, "Intelligent cognitive tutors as modeling tool and instructional model," Invited paper for the National Council of Teachers of Mathematics Standards 2000 Technology Conference, 1998.
  16. L. Amaral and D. Meurers, “From recording linguistic competence to supporting inferences about language acquisition in context,” Computer Assisted Language Learning, vol. 21, no. 4, 2008, pp. 323-338.
  17. D. Weld, “An Introduction to Least Commitment Planning,” AI Magazine, vol. 15, no. 4, 1994.
  18. W. Swartout, R. Hill, J. Gratch, W. L. Johnson, C. Kyriakakis, C. LaBore, R. Lindheim, S. Marsella, D. Miraglia, B. Moore, J. Morie, J. Rickel, M. ThiÚbaux, L. Tuch, R. Whitney, and J. Douglas, "Toward the Holodeck:Integrating graphics, sound, character and story," Int'l Conf. on Autonomous Agents, 2001.
  19. M. Riedl and R. Young, "The Importance of Narrative as an Affective Instructional Strategy," In R. Sottilare, A. Graesser, X. Hu, and B. Goldberg (Eds.), Design Recommendations for Adaptive Intelligent Tutoring Systems: Adaptive Instructional Strategies, vol. 2. Army Science Laboratory, 2014.
  20. R. Reiter, "The Situation Calculus Ontology," Electronic News Journal on Reasoning about Actions and Change, vol. 2, 1998.
  21. M. Georgeff and A. Lansky, "Procedural knowledge," Proceedings of the IEEE Special Issue on Knowledge Representation, vol. 74, 1986, pp. 1383-1398.
  22. J. Park, Formalization of Cyber-Microcosm, Tech. Report #99, AIMM Lab., KNU, 2013.
  23. A. Rao and M. Georgeff, "Modeling rational agents within a BDI Architecture," Proc. Of the 2nd International Conf. on Principles of Knowledge Representation and Reasoning, 1991, pp. 473-484.
  24. M. Wooldridge, Reasoning about Rational Agents, MIT Press, Cambridge, MA, 2000.
  25. W. Hoek and M. Wooldridge, Towards a logic of rational agency, Logic Journal of IGPL, vol. 11, no.2, Oxford Univ. Press, 2003, pp. 133-157.
  26. Mark O. Riedl and A. Stern, “Believable agents and intelligent story adaptation for interactive storytelling,” Technologies for Interactive Digital Storytelling and Entertainment, Springer Berlin Heidelberg, 2006, pp. 1-12.
  27. J. Gibson, "The Theory of affordances," In R. Shaw and J. Bransford (eds.), Perceiving, Acting, and Knowing: Toward an Ecological Psychology, Hillsdale, NJ: Lawrence Erlbaum, 1977, pp. 67-82.
  28. G. J. Burghouts, D. K. J. Heylen, M. Poel, Rieks op den Akker, and A. Nijholt, "An Action Selection Architecture for an Emotional Agent," In: Recent Advances in Artificial Intelligence. Proc. of the 16th International FLAIRS, St. Augustine, Florida, 12-14 May 2003.
  29. M. Riedl and R. Young, "An Intent-driven planner for multi-agent story generation," Proc. of the 3rd Int'l Joint Conf. on Autonomous Agents and Multi-agent Systems, 2004.
  30. M. Bratman, Intention, plans and practical reason, Harvard University Press: Cambridge, MA, 1987.
  31. K. Hartsook, A. Zook, S. Das, and M. Riedl, “Toward supporting stories with procedurally generated game worlds,” Proceedings of the 2011 IEEE Conference on Computational Intelligence in Games.
  32. J. Choi and J. Park, "An Effective implementation of agent's complex actions by reusing primitive motions," Proc. of Simultech, Vienna, Austria, Aug. 2014.
  33. A. Shoulson, F. Garcia, M. Jones, R. Mead, and N. Badler, “Parameterizing Behavior Trees,” In Motion In Games, Springer, 2011, pp. 144-155.
  34. D. Pizzi, F. Charles, J. Lugrin, and M. Cavazza, Interactive Storytelling with Literary.
  35. M. Kapadia, S. Singh, G. Reinman, and P. Faloutsos, “A behavior-authoring framework for multiactor simulations,” Computer Graphics and Applications, vol. 31, no. 6, 2011, pp. 45-55.
  36. M. Cavazza, F. Charles, and S. J. Mead, "Emergentsituations in interactive storytelling," Proc. of ACM Symposium on Applied Computing (ACM-SAC), Madrid, Spain, 2002.
  37. P. Winston, Artificial Intelligence, Addison-Wesley, Reading, MA, USA, 1992, pp. 119-161.
  38. N. Sgouros, G. Papakonstantinou, and P. Tsanakas, "A Framework for plot control in interactive story systems," Proc. AAAI-96, AAAI Press, 1996.
  39. J. M. Niehaus, B. Li, and M. O. Riedl, "Automated Scenario Adaptation in Support of Intelligent Tutoring Systems," Proc. Of 24th FLAIRS Conference, 2011.
  40. N. Nilsson, Principles of artificial intelligence, Tioga Pub. Co., Palo Alto, CA. USA, 1980.
  41. D. Poole and A. Mackworth, Artificial Intelligence: Foundations of Computational Agents, Cambridge University Press, 2010, pp. 349-355.
  42. R. Siegwart, I. R. Nourbakhsh, and D. Scaramuzza, Introduction to Autonomous Mobile Robots, 2nd edition, The MIT Press, Cambridge, MA, London, England, 2011.
  43. J. Park, Augmented model of behavioral occurrence, Tech. Report #72, AIMM Lab., KNU, 2009.
  44. J. Kelly, A. Botea, and S. Koenig, "Offline Planning with Hierarchical Task Networks in Video Games," Proceedings of the Fourth Artificial Intelligence and Interactive Digital Entertainment Conference, Palo Alto, CA, 2008.
  45. M. Si, S. Marsella, and D. Pynadath, "Evaluating directorial control in a character-centric interactive narrative framework," Proceedings of the 9th International Conference on Autonomous Agents and Multiagent Systems, vol. 1, 2010, pp. 1289-1296.
  46. M. Cavazza, F. Charles, and S. Mead, "Interacting with virtual characters in interactive storytelling," ACM Joint Conference on Autonomous Agents and Multi-Agent Systems, Bologna, Italy, 2002, pp. 318-325.
  47. R. Tsuneto, D. Nau, and J. Hendler, "Plan-refinement strategies and search-space size," Proceedings of the 4th European Conference on Planning: Recent Advances in AI Planning, 1997, pp. 414-426.
  48. F. Charles, J. Porteous, M. Cavazza, and J. Teutenberg, "Timeline-based navigation for interactive narratives," Proceedings of the 8th International Conference on Advances in Computer Entertainment Technology, ACE 2011, Lisbon, Portugal, Nov. 8-11, 2011.
  49. El Mokhtar En-Naimi, Abdelhamid Zouhair, Benaissa Amami, Hadhoum Boukachour, Patrick Person, and Cyrille Bertelle, “Intelligent Tutoring Systems Based on the Multi-Agent Systems (ITS-MAS): The Dynamic and Incremental Case Based Reasoning (DICBR) Paradigm and the Inverse Longest Common Sub-Sequence (ILCSS) in the CEHL,” IJCSI International Journal of Computer Science Issues, vol. 9, issue. 6, no. 3, Nov. 2012.
  50. A. Shoulson, N. Marshak, M. Kapadia, and N. Badler, “ADAPT: the agent development and prototyping testbed,” Proceedings of the ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games 2013.
  51. H. Gebre and J. Park, "A Knowledge Representation Scheme Formalizing Spatio-Temporal Aspects of Dynamic Situations in the Virtual Environment," to appear in Journal of KCA, 2015.
  52. G. Jung and J. Park, “An Implementation of Spatio-Temporal Graph to represent situations in the virtual world,” Journal of KCA, vol. 13, no. 6, 2013, pp. 9-19
  53. E. Durfee and V. Lesser, "Incremental planning to control a blackboard-based problem solver," Proceedings of theFifth National Conference on Artificial Intelligence, Philadelphia, PA, 1986, pp. 58-646.
  54. J. Park, The Ontology about the Cyber-Microcosm, Tech. Report #55, AIMM Lab., KNU, 2004.
  55. J. Gruber, Lexical structure in syntax and semantics, North Holland Pub., New York, 1976.
  56. A. Aamodt and E. Plaza, “Case-based reasoning: foundational issues, methodological variations, and system approaches,” Artificial Intelligence Communications, vol. 7, no. 1, 1994, pp. 39-52.
  57. S. Epp, Discrete Mathematics with Applications, Wadsworth, Inc. Belmont, CA, USA, 1990, pp. 294-295.
  58. I. Kim and J. H. Park, “Logical Simulation Platform of Discretionary Events in Spatio-Temporal Context,” Journal of KIISE, vol. 29. no. 6, 2002, pp. 377-385.
  59. W. Frawley, Linguistic Semantics, Lawrence Erlbaum Associates, Hillsdale, NJ, 1992, pp. 197-249.
  60. B. Davey and H. Priestley, "Maps between ordered sets," Introduction to Lattices and Order (2nd ed.), New York: Cambridge University Press, 2002, pp. 23-24.
  61. N. Hiralla, B. Falchuk, and A. Karmouch, “A Temporal model for interactive multimedia scenarios”, IEEE Multimedia, vol.2, no. 3, 1995, pp. 24-31.
  62. C. Date, An Introduction to Database Systems, 7th ed., Addison-Wesley Pub. Co., Reading, MA, 2000.


Grant : 차세대 컴퓨터 교육시스템 및 게임을 위한 가상 거주자의 개발

Supported by : 경북대학교