In their book Commitment in Dialogue, Walton and Krabbe claim that formal dialogue systems for conversational argumentation are “not very realistic and not easy to apply”. This difficulty may make argumentation theory less well adapted to be employed to describe or analyse actual argumentation practice. On the other hand, the empirical study of real-life arguments may miss or ignore insights of more than the two millennia of the development of philosophy of language, rhetoric, and argumentation theory. In this paper, we (...) propose a novel methodology for adapting such theories to serve as applicable tools in the study of argumentation phenomena. Our approach is both theoretically-informed and empirically-grounded in large-scale corpus analysis. The area of interest are appeals to ethos, the character of the speaker, building upon Aristotle’s rhetoric. Ethotic techniques are used to influence the hearers through the communication, where speakers might establish, but also emphasise, weaken or undermine their own or others’ credibility and trustworthiness. Specifically, we apply our method to Aristotelian theory of ethos elements which identifies practical wisdom, moral virtue and goodwill as components of speakers’ character, which can be supported or attacked. The challenges we identified in this case and the solutions we proposed allow us to formulate general guidelines of how to exploit rich theoretical frameworks to the analysis of the practice of language use. (shrink)

Explainable artificial intelligence has become a vitally important research field aiming, among other tasks, to justify predictions made by intelligent classifiers automatically learned from data. Importantly, efficiency of automated explanations may be undermined if the end user does not have sufficient domain knowledge or lacks information about the data used for training. To address the issue of effective explanation communication, we propose a novel information-seeking explanatory dialogue game following the most recent requirements to automatically generated explanations. Further, we generalise our (...) dialogue model in form of an explanatory dialogue grammar which makes it applicable to interpretable rule-based classifiers that are enhanced with the capability to provide textual explanations. Finally, we carry out an exploratory user study to validate the corresponding dialogue protocol and analyse the experimental results using insights from process mining and argument analytics. A high number of requests for alternative explanations testifies the need for ensuring diversity in the context of automated explanations. (shrink)

Ethotic arguments, such as arguments from expert opinion and ad hominem arguments, play an important role in communication practice. In this paper, we argue that there is another type of reasoning from ethos, in which people argue about actions in the world. These subspecies of ethotic arguments are very common in public debates: societies are involved in heated disputes about what should be done with monuments of historical figures such as Stalin or Colston: Should we demolish the building they funded? (...) Should we revere their statues? Should the street named after them be renamed?; and the general public vividly argue about what should be done with the legacy of producers, directors and actors in debates of the #MeToo movement: Should their new movies be distributed? Should their scenes be deleted from motion pictures? Should their stars from the Hollywood Walk of Fame be removed? Many arguments in these debates boil down to the character of the public figures: He was a slave trader!—But he is a part of our history; He harassed a young girl!—But he is an important actor. The reasoning step here is legitimised by the association between a person and an extra-linguistic object: the association between a historical figure and their statue or between an actor and their movie. The nature of this association is explained in the paper using Peirce’s theory of signs. We propose to extend an existing approach to patterns of reasoning from ethos that will help us to shed new light on ethotic argumentation and open an avenue for a systematic account of these unexplored argument forms. (shrink)