Dialogue Game Research Articles

DIAGAL: An Agent Communication Language Based on Dialogue Games and Sustained by Social Commitments

In recent years, social commitment based approaches have been proposed to solve problems issuing from previous mentalistic based semantics for agent communication languages. This paper follows the same line of thought since it presents the latest version of our dialogue game based agent communication language --- DIAlogue-Game based Agent Language (DIAGAL) --- which allows agents to manipulate the public layer of social commitments through dialogue, by creating, canceling and updating their social commitments. To make apparent such commitments, we consider here Agent Communication Language (ACL) from the dialectic point of view, where agents "play a game" based on commitments. Such games based on commitments are incorporated in the DIAGAL language, which has been developed having in mind the following questions: (a) What kind of structure does the game have? How are rules specified within the game? (b) What kind of games compositions are allowed? (c) How do participants in conversations reach agreement on the current game? How are games opened or closed? Using such games we show how we can study the commitments dynamic to model agent dialogue and we present metrics that can be used to evaluate the quality of a dialogue between agents. Next, we use an example (summer festival organization) to show how DIAGAL can be used in analyzing and modeling automated conversations in offices. Finally, we present the results and analysis of the summer festival simulations that we realized through our dialogue game simulator (DGS).

The eightfold way of deliberation dialogue

Deliberation dialogues occur when two or more participants seek to jointly agree on an action or a course of action in some situation. We present the first formal framework for such dialogues, grounding it in a theory of deliberative reasoning from the philosophy of argumentation. We further fully articulate the locutions and rules of a formal dialogue game for this model, so as to specify a protocol for deliberation dialogues. The resulting protocol is suitable for dialogues between computational entities, such as autonomous software agents. To assess our protocol, we consider it against various records of human deliberations, against normative principles for the conduct of human dialogues, and with respect to the outcomes produced by dialogues undertaken according to the protocol. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 95–132, 2007.

Pragmatic inference and argumentation in intercultural communication

The paper addresses intercultural variability in argumentation, and, more specifically, the variation in the judgments concerning the reasonableness of arguments across cultures. Such variability represents a key issue in intercultural communication, and, at the same time, has been taken as an argument for logical relativism. A brief review of the contrastive discourse analysis literature, and, in particular, of the Contrastive Rhetoric tradition, shows that there is considerable vagueness with respect to whether cultural variation in argumentation concerns the logic proper or other levels of discourse organization. The paper argues that a conceptual framework based on argumentation theory and inferential pragmatics allows for the identification of two likely sites for cross-cultural variability of pragmatic, extra-logical, origin: (1) the reliance of natural enthymematic argument on the recovery of implicit premises from a common ground of culturally shared assumptions (endoxa); and (2) the functioning of the dialogue games in which argumentation appears and their embedding in culturally specific social contexts. In order to account for (1), in particular, a model of the interplay between argumentation and inference is presented, which introduces a key distinction between pragmatic (communicative) inferences and argumentative (commmunicated) inferences.

Coherence and Flexibility in Dialogue Games for Argumentation

This article carries out a formal study of dialogue games for argumentation. A formal framework for such games is proposed which imposes an explicit reply structure on dialogues, where each dialogue move either attacks or surrenders to some earlier move of the other participant. The framework is flexible in several respects. It allows for different underlying logics, alternative sets of locutions and more or less strict rules for when they are allowed. In particular, it allows for varying degrees of coherence and flexibility when it comes to maintaining the focus of a dialogue. Its formal nature supports the study of formal properties of specific dialogue protocols, especially on how they respect the underlying logic.

A Dialogue Game Protocol for Multi-Agent Argument over Proposals for Action

We present the syntax and semantics for a multi-agent dialogue game protocol which permits argument over proposals for action. The protocol, called the Persuasive Argument for Multiple Agents (PARMA) Protocol, embodies an earlier theory by the authors of persuasion over action which enables participants to rationally propose, attack, and defend, an action or course of actions (or inaction). We present an outline of both an axiomatic and a denotational semantics, and discuss implementation of the protocol, in the context of both human and artificial agents.

Agent communication pragmatics: the cognitive coherence approach

Different approaches have investigated the syntax and semantics of agent communication languages. However, these approaches have not indicated how agents should dynamically use communications. Instead of filling this pragmatics gap, most approaches have mainly focused on the ‘structure’ of dialogues even though developers are more interested in agents’ capabilities of having ‘useful’ automated conversations with respect to their goals rather than in their abilities to structure dialogues. This led us to work on a theory of the use of conversations between agents. In this paper, we propose a pragmatics theory which extends and adapts the cognitive dissonance theory (a major theory of social psychology) to multi-agent systems by unifying it with the theory of coherence in thought and action that issues from computational philosophy of mind. Precisely, we show how this theory allows us to provide generic conceptual tools for the automation of both agent communicational behavior and attitude change processes. This new motivational model is formulated in terms of constraints and elements of cognition and allows us to define cognitive incoherences and dialogue utility measures. We show how these measures could be used to solve common problems and answer some critical questions concerning agent communication frameworks use. Finally, our exploration in applying the cognitive coherence pragmatics theory as a new communication layer over classical BDI agents is presented. It relies on our dialogue games based agent communication language (DIAGAL) and our dialogue games simulator toolbox (DGS). The resulting framework provides the necessary theoretical and practical elements for implementing our theory. In doing so, it brings in a general scheme for automatizing agents’ communicational behavior as it is exemplified in this article.

Remembering Bill Mann

William C. Mann passed away on August 13, 2004, after a long struggle with leukemia. He is known to readers of Computational Linguistics as a keen supporter and past president (1987) of ACL, a pioneer in the development of text generation as a field of research in computational linguistics, the originator of rhetorical structure theory (RST) and dialogue game theory (DGT), and the developer (together with David Weber) of dialect adaptation as a technique within machine translation. And he’ll be remembered for these and many other contributions, but above all, in this context, he’ll be remembered as a unique visionary in computational linguistics (CL) and as a truly wonderful and extraordinarily generous colleague. Bill Mann made huge contributions to many people’s intellectual development, to their careers, and to their lives in general. What follows are my own recollections of him, selected from a crowded jungle of memories. I will leave it to others to fill out the picture, but I shall attempt to give an indication of the intellectual and historical context in which Bill was working and also of the network of researchers that he created; his ideas have radiated throughout this network of scholars around the world. I met Bill in April 1980 and worked as a research linguist on a succession of projects he directed, or codirected, at the Information Sciences Institute (ISI) at the University of Southern California (USC), until I left the institute to take up a position at the University of Sydney in August 1988. Through that period (which happened to coincide, more or less, with the Reagan years), not only was Bill a very wise and wonderful project leader, but he also became a mentor and guide and a true friend. I followed from afar the further developments in his life: his departure from ISI and move to Kenya with his family to take up a position with the Summer Institute of Linguistics (SIL) as a consultant responsible for work on discourse and computational matters, their return to the United States, and his new phase of research with initiatives in RST and DGT.

Combining interaction and context design to support collaborative argumentation using a tool for synchronous CMC

Abstract Empirical studies and theory suggest that educational dialogue can be used to support learners in the development of reasoning, critical thinking and argumentation. This paper presents an educational design for synchronous online peer discussion that guides student dialogue in ways that lead to improved argumentation and collaborative knowledge development. This design includes a mediating interface – or tool, linked to a broader set of online educational activities – a designed local context, where the latter aims to provide conditions that support argumentation. The approach is based on collaborative working and dialogue game approaches to discussion. Preliminary findings with UK Open University students showed the argumentation process was more coherent, varied, deeper and extended when using our interaction design compared with the use of a simple unstructured interface.

Dialogue Games for Inconsistent and Biased Information

In this article, a dialogue game is presented in which coherent conversational sequences with inconsistent and biased information are described at the speech act level. Inconsistent and biased information is represented with bilattice structures, and based on these bilattice structures, a multi-valued logic is defined that makes it possible to describe a dialogue game in which agents can communicate about their cognitive states with inconsistent and biased information. A dialogue game is formalized by, first, defining the agent's cognitive state as a set of multi-valued theories, second, by defining the dialogue rules that prescribe permissible communicative acts based on the agent's cognitive state, and last, by defining update rules that change the agent's cognitive state as a result of communicative acts. We show that an example dialogue with inconsistent and biased information can be derived from our dialogue game.

Negotiating Dialogue Games

Recently in the field of agent communication, many authors have adopted the view of interaction as a joint activity regulated by means of dialogue games. It is argued in particular that this approach should increase the flexibility of dialogues by allowing a variety of game compositions. In this research note, we present a framework suited to this feature. A preliminary attempt to capture the negotiation phase (which allows agents to agree upon the dialogue game currently regulating their conversation) is discussed.

A Dialogue Game Protocol for Agent Purchase Negotiations

We propose a dialogue game protocol for purchase negotiation dialogues which identifies appropriate speech acts, defines constraints on their utterances, and specifies the different sub-tasks agents need to perform in order to engage in dialogues according to this protocol. Our formalism combines a dialogue game similar to those in the philosophy of argumentation with a model of rational consumer purchase decision behaviour adopted from marketing theory. In addition to the dialogue game protocol, we present a portfolio of decision mechanisms for the participating agents engaged in the dialogue and use these to provide our formalism with an operational semantics. We show that these decision mechanisms are sufficient to generate automated purchase decision dialogues between autonomous software agents interacting according to our proposed dialogue game protocol.

Prosodic marking of information status in Dutch and Italian: a comparative analysis

This article reports on a comparative analysis of accentuation strategies within Italian and Dutch noun phrases (NPs). Its goal is not only to gain insight into what speakers do, but also into how listeners' perception and interpretation of incoming speech in different languages is affected by the distribution of accents. To this end, use is made of a particular experimental paradigm, which makes it possible to compare accent patterns in different languages from an acoustic, perceptual and functional point of view. Accent patterns were obtained via a simple dialogue game played by eight Dutch speakers and eight Italian ones. In this way, target descriptions of all speakers were obtained in the following four contexts: all new, single contrast in the adjective, single contrast in the noun, and double contrast. The accent patterns in these Dutch and Italian utterances were then compared in three different studies. Study 1 looks at accent distribution and finds that, in Dutch, new and contrastive information are accented, while given information is not; in Italian, distribution is not a significant factor in distinguishing information status, since within the elicited NPs both adjective and noun are always accented, irrespective of the status of the discourse context. Study 2 consists of prominence tests to investigate whether the accents differ in the degree of perceived emphasis. In Dutch, information status is reflected in these prominence differences: single contrastive accents are perceived to be the most emphatic, and given words the least emphatic. In Italian, it is less clear how gradient differences between accents can be linked to aspects of the discourse context. Study 3 presents a functional analysis of accent patterns exploring whether listeners are able to reconstruct a preceding utterance on the basis of prosodic properties of the current utterance. While this is possible for Dutch listeners, this is not at all the case for Italian listeners.

A Geometric Semantics for Dialogue Game Protocols for Autonomous Agent Interactions

Formal dialogue games studied by philosophers since the time of Aristotle have recently found application in Artificial Intelligence as the basis for protocols for interactions between autonomous software agents. For instance, game protocols have been proposed for agent dialogues involving team formation, persuasion, negotiation and deliberation. There is yet, however, no formal, mathematical theory of dialogue game protocols with which to compare two protocols or to study their formal properties. In this paper,11Partly funded by the EU IST Programme through the Sustainable Lifecycles in Information Ecosystems (SLIE) Project (IST-1999–10948) and by the British Engineering and Physical Sciences Research Council (EPSRC) through a PhD studentship. We are also grateful for comments from the anonymous referees, the audience at the GETCO-2001 workshop in Aalborg, Mark Johnson and Grant Malcolm. we present preliminary work towards such a theory, in which we develop a geometric semantics for these protocols and, with it, define a notion of equivalence between two protocols. We then demonstrate an algebraic property of protocol equivalence, and use this to show the non-equivalence of two similar generic protocols. We also explore the relationship between finite and infinite dialogues, motivated by the Ehrenfeucht-Fraïssé games of model theory. Our results have implications for the design and evaluation of agent dialogue-game protocols.

Developing and evaluating dialogue games for collaborative e–learning

Abstract This paper argues that developments in collaborative e‐learning dialogue should be based on pedagogically sound principles of discourse, and therefore, by implication, there is a need to develop methodologies which transpose — typically informal — models of educational dialogue into cognitive tools that are suitable for students. A methodology of ‘investigation by design’ is described which has been used to design computer‐based dialogue games supporting conceptual change and development in science — based on the findings of empirical studies. An evaluation of two dialogue games for collaborative interaction, a facilitating game and an elicit‐inform game, has shown that they produce significant improvements in students conceptual understanding, and they are differentially successful — depending on the nature of the conceptual difficulties experienced by the learners. The implications this study has for the role of collaborative dialogue in learning and designing computer‐based and computer–mediated collaborative interaction are discussed.

Games That Agents Play: A Formal Framework for Dialogues between Autonomous Agents

We present a logic-based formalism for modeling of dialogues between intelligent and autonomous software agents, building on a theory of abstract dialogue games which we present. The formalism enables representation of complex dialogues as sequences of moves in a combination of dialogue games, and allows dialogues to be embedded inside one another. The formalism is computational and its modular nature enables different types of dialogues to be represented.

A Logic for Suspicious Players: Epistemic Actions and Belief–Updates in Games

This paper introduces a notion of ‘epistemic action’ to describe changes in the information states of the players in a game. For this, ideas are developed from earlier contributions. The ideas are enriched to cover not just purely epistemic actions, but also fact–changing actions (‘real moves’, e.g. choosing a card, exchanging cards etc.) and nondeterministic actions and strategies (conditional actions having knowledge tests as conditions). The author considers natural operations with epistemic actions and uses them to describe significant aspects of the interaction between beliefs and actions in a game. A logic is used that combines in a specific way a multiagent epistemic logic with a dynamic logic of ‘epistemic actions’. The author presents a complete and decidable proof system for this logic. As an application, the author analyses a specific example of a dialogue game (a version of the Muddy Children Puzzle, in which some of the children can ‘cheat’ by engaging in secret communication moves, while others may be punished for their credulity). Also presented is a sketch of a ‘rule–based’ approach to games with imperfect information (allowing ‘sneaky’ possibilities, such as cheating, being deceived and suspecting the others to be cheating).

Relating dialogue games to information state

This paper discusses the use of `conversational' or `dialogue games' as a basis for building dialogue systems. We give a tutorial overview of some recent attempts to relate the notion of a dialogue act to changes of information state of the participants in a dialogue. These attempts all distinguish some notion of `grounded' or `common' propositions. We raise the question as to whether these attempts might make the notion of dialogue game redundant, reducing it to an epiphenomenon arising out of the manipulation of information states. The answer to the question is no, not quite, yet. We also look briefly at a suggestion for augmenting the notion of information state so as to be able to deal with some types of prosodically marked focus.

On the generation of coherent dialogue

A dialogue game is presented that enables us to generate coherent elementary conversational sequences at the speech act level. Central to this approach is the fact that the cognitive states of players change as a result of the interpretation of speech acts and that these changes provoke the production of a subsequent speech act. The rules of the game are roughly based on the Gricean maxims of co-operation — i.e., agents are forbidden to put forward information they do not believe and are forbidden to ask anything they already believe; the Gricean maxim of relevance is determined by a so-called imbalance in the players’ belief and desire states. As in realistic conversational situations, it is assumed that the information needed to answer a question can be present in a distributed manner. Consequently, the structure of the dialogues may become rather complex, and may result in the generation of counter-questions and sub-dialogues. It will be shown that the structure and the coherence of conversational units do not necessarily have to be the product of a complex planning process or a speech act grammar, but can be based on elementary generation rules that take only into account the local context. As a result, the conversational game does not suffer from the same computational complexity as existing planning models for speech act generation. Although simple in its basic form, the framework enables us to produce abstract conversations with some properties that agree strikingly with dialogue properties found in Conversation Analysis.

Designing E‐learning Interactions in the 21st Century: revisiting and rethinking the role of theory

In this article, I shall consider research and development in e-learning in terms of learning processes and interactions that are stimulated, supported and favoured by innovative educational technologies. I examine relationships between learning theory and interaction design by reviewing and critiquing a relevant selection of work that has been undertaken in the last 50 years. Implicit in this review is the development of an argument that emphasises the role of collaborative dialogue and discourse in the learning process, with particular reference to Vygotsky’s theory of the development of higher mental processes. In evaluating the roles that computers can play in supporting effective educational interaction, the importance of dialogue models and dialogue games is proposed; and the implications which these paradigms hold for how we actually conceive of design are articulated. E-learning: half a century of design The notion that ‘electronic learning’ is a recent initiative is a popular misconception. Arguably, electronic learning (hereafter e-learning) started in the 1950s. We should be mindful of this and initiatives since then when we consider the current feverish interest and activity in exploiting maturing Internet technologies, particularly in the context of open and distance learning (ODL) and to design virtual learning environments (VLEs), on-line courses, virtual universities and the like. Are these initiatives properly exploiting the highly interactive, communicative and participative possibilities provided by contemporary technologies? Or are we simply replicating or augmenting ‘conventional’ approaches to teaching and learning, locally or at a distance, in ways that downplay the opportunity to re-evaluate ‘what it actually takes to learn’ and thus ignoring ways of developing more innovative and improved pedagogical practices. I suggest that we should step back from the more practical and institutional concerns for a moment and focus on more fundamental issues concerning the learning processes and interactions that are, or can be, supported by innovative educational technologies. This focus is relevant to all levels of education. I argue

On the alleged existence of contrastive accents

Speakers may use pitch accents as pointers to new information, or as signals of a contrast relation between the accented item and a limited set of alternatives. There is no consensus in the literature whether a separately identifiable contrastive accent exists. Some studies report that contrastive accents are more emphatic than newness accents and have a different melodic shape. In other studies, however, it is maintained that contrastiveness can only be determined by looking at how accents are distributed in an utterance. It is argued that these two contrasting views on contrastiveness can be reconciled by showing that they apply on different levels. To this end, accent patterns were obtained in a (semi-)spontaneous way via a dialogue game (Dutch) in which two participants had to describe coloured figures in consecutive turns. By varying the sequential order, target descriptions (`blue square') were collected in four contexts: no contrast (all new), contrast in the adjective, contrast in the noun, all contrast. A distributional analysis revealed that both all new and all contrast situations correspond with double accents, whereas single accents on the adjective or the noun are used when these are contrastive. Single contrastive accents on the adjective are acoustically different from newness accents in the same syntactic position. The former have the shape of a `nuclear' accent, whereas the newness accents on the adjective are `prenuclear'. Contrastive accents stand out as perceptually more prominent than newness accents. This difference in salience tends to disappear if the accented word is heard in isolation.