The paper describes four dialogue systems, developed in the tradition of Charles Hamblin. The first system provides an answer for Achilles in Lewis Carroll's parable, the second an analysis of the fallacy of begging the question, the third a non-psychologistic account of conversational implicature, and the fourth an analysis of equivocation and of objections to it. Each avoids combinatorial explosions, and is intended for real-time operation.

For people to contribute to discourse, they must do more than utter the right sentence at the right time. The basic requirement is that they add to their common ground in an orderly way. To do this, we argue, they try to establish for each utterance the mutual belief that the addressees have understood what the speaker meant well enough for current purposes. This is accomplished by the collective actions of the current contributor and his or her partners, and these (...) result in units of conversation called contributions. We present a model of contributions and show how it accounts for a variety of features of everyday conversations. (shrink)

Natural dialogue does not proceed haphazardly; it has an easily recognized “episodic” structure and coherence which conform to a well developed set of conventions. This paper represents these conventions formally in terms related to speech act theory and to a theory of action.The major formal unit, the dialogue game, specifies aspects of the communication of both participants in a dialogue. We define the formal notion of dialogue games, and describe some of the important games of English. Dialogue games are conventions (...) of interactive goal pursuit. Using them, each participant pursues his own goals in a way which sometimes serves the goals of the other. The idea of dialogue games can thus be seen as a part of a broader theoretical perspective which characterizes virtually all communication as goal pursuit activity.We also define and exemplify the property of Motivational Coherence of dialogues. Motivational Coherence can be used as an interpretive principle in explaining language comprehension.Actual dialogue games have a kind of causal connectedness which is not a consequence of their formal properties. This is explained in terms of a theory of action, which is also seen to explain a similar attribute of speech acts. (shrink)

Walton's book is a study of several fallacies in informal logic. Focusing on question-answer dialogues, and committed to a pragmatic rather than a semantic approach, he attempts to generate criteria for evaluating good and bad questions and answers. The book contains a discussion of such well-recognized fallacies as many questions, black-or-white questions, loaded questions, circular arguments, question-begging assertions and epithets, ad hominem and tu quoque arguments, ignoratio elenchi, and replying to a question with a question. In addition, Walton develops several (...) artificial dialogue games and has an excellent discussion of burden of proof in nonlegal contexts. The discussion is for the most part nontechnical and does not presuppose any training in formal logic. It is illustrated with many (sometimes overlong) examples of fallacies drawn from real life--mostly debates in the Canadian House of Commons. . . . Walton's book breaks new ground on a number of issues. Choice This first full-length study of logical fallacies, errors, faults, illicit attacks, blunders, and other critical deficiencies in interrogation and reply has been written in the tradition of informal fallacies in logic. It is especially valuable, readable, and interesting because of the 139 case studies it presents, many of these case studies come from political debates and some from interviews, legal cross-examinations, and other sources. Walton uses these challenging examples of tricky, aggressive, argumentative, or fallacious questions to develop coherent and pragmatic guidelines for criticizing questionable questions (and in some cases their replies) on logical grounds. Among the types of problematic questions analyzed are: the traditional so-called fallacy of many questions, illustrated by the famous Have you stopped beating your wife?; black and white questions; terminologically loaded questions; and questions containing personal attacks. These and other types of problematic questions as well as evasive replies and replying to a question with a question are studied. Critical errors of reasoning are identified and analyzed by developing context-based, normative models of reasonable dialogue in which a questioner must have freedom to ask informative and probing questions, and the respondent must be constrained to give reasonably direct, not overly evasive answers. In this era of negative and evasive political campaigning, with candidates employing skillful tactics of manipulating public opinion to assure election rather than taking clear stands and seriously debating issues in an informed and sincere manner, Question-Reply Argumentation is especially relevant reading for those who take democracy seriously. The methods used reflect a significant shift from earlier semantically based theories to current pragmatic, dialogue-based models, and will be of interest to logicians and linguists. The volume's conclusions should challenge some current preconceptions. Recommended reading for courses in logic, speech communications, linguistics, philosophy of language, areas of political science relating to political discourse and debate, courses on questioning in cognitive psychology, and courses on critical thinking in education. (shrink)

Our studies of naturally occurring human dialogue have led to the recognition of a class of regularities which characterize impoltant aspects of communication. People appear to interact according to established patterns which span several turns in a dialogue and which recur frequently. These patterns appear to be organized around the goals which the dialogue serves for each participant. Many things which are said later in a dialogue can only be interpreted as pursuit of these goals, established by earlier dialogue.These patterns (...) have been represented b) a set of knowledge structures called Dialogue‐Games, capturing shared, conventional knowledge that people have about communication and how it can be used to achieve goals. A Dialogue‐Game has Parameters, which represent those elements that vary across instances of a particular pattern‐the particular dialogue participants and the content topic. The states of the world which must be in effect for a particular Dialogue‐Game to be employed successfully are represented by Specifications of these Parameters. Finally, the expected sequence of intermediate states that occur during instances of a particular conventional pattern are represented by the Components of the corresponding Dialogue‐Game.Representations for several Dialogue‐Games are presented here, based on our analyses of different kinds of naturally occurring dialogue. A process model is discussed, showing Dialogue‐Game identification, pursuit, and termination as part of the comprehension of dialogue utterances. This Dialogue‐Game model captures some of the important functional aspects of language, especially indirect uses to achieve implicit communication. (shrink)