Confidence in Arguments in Dialogues for Practical Reasoning

For the context of practical reasoning, this paper suggests a method of assessing the level of confidence we should rationally have in arguments. It draws from dialectic which induces the elaboration of reasons for a position and on auditors’ prior knowledge. Accurate assessment depends on evidential standards, on selecting dialogue moves according to their practical and epistemic importance, and on selecting auditors according to their competence and diversity of relevant knowledge

Implementing a Theory of a Legal Domain

We describe a system for constructing, evaluating and visualising arguments based on a theory of a legal domain, developed using the Angelic methodology and the Carneades argumentation system. The visualisation can be used to explain particular cases and to refine and maintain the theory. A full implementation of the well known US Trade Secrets Domain is used to illustrate the process.</jats:p

In memoriam Douglas N. Walton: the influence of Doug Walton on AI and law

Doug Walton, who died in January 2020, was a prolific author whose work in informal logic and argumentation had a profound influence on Artificial Intelligence, including Artificial Intelligence and Law. He was also very interested in interdisciplinary work, and a frequent and generous collaborator. In this paper seven leading researchers in AI and Law, all past programme chairs of the International Conference on AI and Law who have worked with him, describe his influence on their work

Joint attacks and accrual in argumentation frameworks

While modelling arguments, it is often useful to represent joint attacks, i.e., cases where multiple arguments jointly attack another (note that this is different from the case where multiple arguments attack another in isolation). Based on this remark, the notion of joint attacks has been proposed as a useful extension of classical Abstract Argumentation Frameworks, and has been shown to constitute a genuine extension in terms of expressive power. In this chapter, we review various works considering the notion of joint attacks from various perspectives, including abstract and structured frameworks. Moreover, we present results detailing the relation among frameworks with joint attacks and classical argumentation frameworks, computational aspects, and applications of joint attacks. Last but not least, we propose a roadmap for future research on the subject, identifying gaps in current research and important research directions.Fil: Bikakis, Antonis. University College London; Estados UnidosFil: Cohen, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Dvoák, Wolfgang. Technische Universitat Wien; AustriaFil: Flouris, Giorgos. Foundation for Research and Technology; GreciaFil: Parsons, Simon. University of Lincoln; Reino Unid

Defining argument weighing functions

Dung designed abstract argumentation frameworks [8] to model attack relations among arguments. However, a common and arguably more typical form of human argumentation, where pros and cons are weighed and balanced to choose among alternative options, cannot be simply and intuitively reduced to attacks. [12] defined a new formal model of structured argument which generalizes Dung abstract argumentation frameworks to provide better support for argument weighing and balancing, enabling cumulative arguments and argument accrual to be handled without causing an exponential blowup in the number of arguments. Dung proposed a pipeline model of argument evaluation for abstract argumentation frameworks, where first all the arguments are evaluated and labeled, at the abstract level, and then, in a subsequent process, the premises and conclusions of the arguments are labeled, at the structured argument level. This pipeline model makes it impossible to make the weight of arguments depend on the labels of their premises. To overcome this problem, in the new model of [12] the weight of arguments and labels of statements can depend on each other, in a mutually recursive manner. The new model is a framework which can be instantiated with a variety of argument weighing functions. In this article, this feature is illustrated by defining a number of argument weighing functions, including: 1) simulating linked and convergent arguments, by making the weight of an argument depend on whether all or some of its premises are labeled in, respectively; 2) making the weight of an argument depend on one or more meta-level properties of the argument, such as the date or authority of the scheme instantiated by the argument; 3) modeling a simple form of cumulative argument, by making the weight of an argument depend on the percentage of its in premises; 4) making the weight of an argument depend on the percentage of its in “factors”, from a set of possible factors, where premises represent factors; and, finally 5) making the weight of an argument depend on a weighted sum of the in properties of an option, in the style of multi-criteria decision analysis, where premises model properties of an option