Argument Schemes and Dialogue Protocols: Doug Walton's legacy in artificial intelligence

This paper is intended to honour the memory of Douglas Walton (1942--2020), a Canadian philosopher of argumentation who died in January 2020. Walton's contributions to argumentation theory have had a very strong influence on Artificial Intelligence (AI), particularly in the design of autonomous software agents able to reason and argue with one another, and in the design of protocols to govern such interactions. In this paper, we explore two of these contributions --- argumentation schemes and dialogue protocols --- by discussing how they may be applied to a pressing current research challenge in AI: the automated assessment of explanations for automated decision-making systems

Automata for infinite argumentation structures

The theory of abstract argumentation frameworks (afs) has, in the main, focused on finite structures, though there are many significant contexts where argumentation can be regarded as a process involving infinite objects. To address this limitation, in this paper we propose a novel approach for describing infinite afs using tools from formal language theory. In particular, the possibly infinite set of arguments is specified through the language recognized by a deterministic finite automaton while a suitable formalism, called attack expression, is introduced to describe the relation of attack between arguments. The proposed approach is shown to satisfy some desirable properties which cannot be achieved through other “naive” uses of formal languages. In particular, the approach is shown to be expressive enough to capture (besides any arbitrary finite structure) a large variety of infinite afs including two major examples from previous literature and two sample cases from the domains of multi-agent negotiation and ambient intelligence. On the computational side, we show that several decision and construction problems which are known to be polynomial time solvable in finite afs are decidable in the context of the proposed formalism and we provide the relevant algorithms. Moreover we obtain additional results concerning the case of finitaryafs

More on Non-Cooperation in Dialogue Logic

Stone-walling dialogues are exercises in structured non-cooperation. It is true that dialogue participants need to cooperate with one another and in ways su#cient to make possible the very dialogue they are now having. Beyond that there is room for non-cooperation on a scale that gives great o#ence to what we call the Goody Two-Shoes Model of argument. In this paper, we argue that noncooperation dialogues have perfectly legitimate objectives and that in relation to those objectives they need not be considered at all subpar to conversations that brim with sunny amity