We describe ongoing research towards modelling dialogue management for conversational agents that can exhibit and cope with non-cooperative behaviour. Empirical studies of conventional dialogue behaviour in the domain of political interviews and a coarse-grained notion of conversational games  re used to characterise non-cooperation. We propose an agent architecture that combines conversational games and discourse obligations, and suggest an implementation

Piwek, Paul

Plüss, Brian

Power, Richard

English

Open Research Online

Open Research OnlineThe Open University’s repository of research publicationsand other research outputsModelling non-cooperative dialogue: the role ofconversational games and discourse obligationsConference or Workshop ItemHow to cite:Plu¨ss, Brian; Piwek, Paul and Power, Richard (2011). Modelling non-cooperative dialogue: the role of conversationalgames and discourse obligations. In: SemDial 2011 (Los Angelogue), pp. 212–213.For guidance on citations see FAQs.c© 2011 The AuthorsVersion: Version of RecordLink(s) to article on publisher’s website:http://projects.ict.usc.edu/nld/semdial2011/semdial2011-proceedings.pdfCopyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyrightowners. For more information on Open Research Online’s data policy on reuse of materials please consult the policiespage.oro.open.ac.ukModelling Non-Cooperative Dialogue: the Role of Conversational Gamesand Discourse ObligationsBrian Plu¨ss and Paul Piwek and Richard PowerCentre for Research in ComputingThe Open UniversityMilton Keynes, UK{b.pluss,p.piwek,r.power}@open.ac.ukAbstractWe describe ongoing research towards mod-elling dialogue management for conversa-tional agents that can exhibit and cope withnon-cooperative behaviour. Empirical stud-ies of conventional dialogue behaviour in thedomain of political interviews and a coarse-grained notion of conversational games areused to characterise non-cooperation. We pro-pose an agent architecture that combines con-versational games and discourse obligations,and suggest an implementation.1 IntroductionConsider the dialogue fragment in Figure 11. Itdiffers from typical political interviews, where oneof the participants poses more or less impartialquestions, while the other provides clear and rele-vant answers. This type of dialogue eludes tradi-tional approaches to computational dialogue mod-elling which assume a strong notion of cooperationbetween the participants. Joint intentions (Cohenand Levesque, 1991) or shared plans (Grosz and Sid-ner, 1990), for example, successfully explain situa-tions in which dialogue participants recognise andadopt each other’s intentions and goals.Many naturally-occurring dialogues do, however,not conform to these assumptions. Deviationsfrom conventional behaviour –such as loaded ques-tions, evasive answers, unsolicited comments, etc.,which we refer to as non-cooperative features (Plu¨ss,2010)– do occur. Consequently, shedding light on1BBC presenter Jeremy Paxman interviews MP George Gal-loway after the UK 2005 General Election. Video: http://www.youtube.com/watch?v=SlE5cTcYZbs.Figure 1: General Election Night Interview (BBC, 2005)the nature of non-cooperation in dialogue2 promisesto yield a better understanding of conversation, andmay eventually be of use in applications (e.g. role-playing agents, sophisticated dialogue systems).2 Conversational Games and DiscourseObligationsConversational (or dialogue) games extend speechacts beyond the single utterance, spanning from twosequential utterances to entire conversations (Power,1979). Following Walton and Krabbe (1995), we usea coarse-grained notion of conversational game thatrefers to entire dialogue situations. At this level, agame is seen as a set of rules, a contract participantssubscribe to by agreeing on a specific type of inter-action. An informal example for a (simplified) po-litical interview follows:1. Two participants: an interviewer (IR) and an interviewee (IE).2. IR limits herself to asking questions from a pre-agreed topicalagenda until the agenda is empty.2We refer here to linguistic cooperation, as opposed to non-linguistic (or task-level) cooperation. Plu¨ss (2010) presents adiscussion on this distinction.SemDial 2011: Proceedings of the 15th Workshop on the Semantics and Pragmatics of Dialogue, pages 212–213.Los Angeles, California, 21–23 September 2011.2123. IE limits himself to providing relevant and complete answersto questions until the IR ends the conversation.4. Grounding:- Adequate questions (i.e. in the topical agenda) are accepted.- Inadequate questions are rejected.- Irrelevant or incomplete replies are rejected.- Relevant and complete answers are accepted.5. After accepting an answer, IR moves on to the next question.6. Once all questions have been addressed, IR initiates closing.7. When IR initiates closing, IE completes and the dialogue ends.These rules capture conventional behaviour un-der a certain scenario, as participants are expected toact according to the game’s rules. Discourse obliga-tions resulting from such social pressure have beenused for modelling dialogue management (Traumand Allen, 1994; Matheson et al., 2000). In the ex-ample above, for instance, an adequate question im-poses an obligation on the interviewee to accept it.Discourse obligations follow naturally from con-versational games and are associated with cooper-ation. When obligations are addressed, the rulesof the game are followed and the result is coop-erative behaviour (Traum and Allen, 1994). Non-cooperative dialogue (e.g. the interaction in Figure1) seems to be beyond the limits of such games. Ofcourse, one could add further rules that capture thevariations present in these conversations, but in thelimit this approach would require an additional setof rules for each possible unconventional behaviour.In our work, we use the insights from dialoguegames to provide a description of expected be-haviour in the form of social obligations, but allowagents to bend –or break– the rules. Our hypothesisis that non-cooperative behaviour occurs when par-ticipants favour individual goals that are in conflictwith their current discourse obligations.3 Agent Architecture and PrototypeImplementationWe have implemented a prototype with two au-tonomous agents holding an interview. We followedan information state approach (Traum and Larsson,2003), grouping update and selection rules accord-ing to the architecture shown in Figure 2. The in-formation state has the agenda of individual goals,the dialogue history and pending obligations. Theagents keep the same knowledge about the game, soas to track each other’s obligations, while individ-ual goals are private. After each move, obligationsare updated and a deliberation mechanism decidesFigure 2: Agent architecturewhether to discharge an obligation or follow an in-dividual goal, based on priority settings.Current and future work include the developmentof a good topical domain for the prototype and acomprehensive evaluation.4 ConclusionConversational games capture dialogue conventions,but say little about deviations. By focusing on howdialogue rules can be bent or broken we aim at pro-ducing and coping with a wider range of behaviours.ReferencesP.R. Cohen and H.J. Levesque. 1991. Confirmations andjoint action. In Proceedings of the 12th InternationalJoint Conference on AI, Sydney, Australia.B.J. Grosz and C.L. Sidner. 1990. Plans for discourse.Intentions in communication, pages 417–444.C. Matheson, M. Poesio, and D. Traum. 2000. Mod-elling grounding and discourse obligations using up-date rules. In Proceedings of the 1st NAACL Confer-ence, San Francisco, CA, USA.Brian Plu¨ss. 2010. Non-cooperation in dialogue. In Pro-ceedings of the ACL 2010 Student Research Workshop,ACL-SRW 2010, pages 1–6, Uppsala, Sweden.R. Power. 1979. The organisation of purposeful dia-logues. Linguistics, 17:107–152.D.R. Traum and J.F. Allen. 1994. Discourse obligationsin dialogue processing. In Proceedings of the 32ndannual meeting of ACL. Morristown, NJ, USA.D. Traum and S. Larsson. 2003. The information stateapproach to dialogue management. Current and NewDirections in Discourse and Dialogue, pages 325–353.D. Walton and E. Krabbe. 1995. Commitment in di-alogue: Basic concepts of interpersonal reasoning.State University of New York Press.213

Modelling non-cooperative dialogue: the role of conversational games and discourse obligations

http://oro.open.ac.uk/40217/1/semdial2011_pluss_2.pdf

Modelling non-cooperative dialogue: the role of conversational games and discourse obligations

Abstract

Similar works

Full text

Available Versions

Open Research Online