A Carneades reconstruction of Popov v Hayashi

Carneades is an open source argument mapping application and a programming library for building argumentation support tools. In this paper, Carneades’ support for argument reconstruction, evaluation and visualization is illustrated by modeling most of the factual and legal arguments in Popov v Hayashi

Modeling critical questions as additional premises

This paper shows how the critical questions matching an argumentation scheme can be mod-eled in the Carneades argumentation system as three kinds of premises. Ordinary premises hold only if they are supported by sufficient arguments. Assumptions hold, by default, until they have been questioned. With exceptions the negation holds, by default, until the exception has been supported by sufficient arguments. By “sufficient arguments”, we mean arguments sufficient to satisfy the applicable proof standard

Formalizing Informal Logic

In this paper we investigate the extent to which formal argumentation models can handle ten basic characteristics of informal logic identified in the informal logic literature. By showing how almost all of these characteristics can be successfully modelled formally, we claim that good progress can be made toward the project of formalizing informal logic. Of the formal argumentation models available, we chose the Carneades Argumentation System (CAS), a formal, computational model of argument that uses argument graphs as its basis, structures of a kind very familiar to practitioners of informal logic through their use of argument diagrams

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

An Argumentation Interface for Expert Opinion Evidence

Tribunals have come to depend increasingly on expertise for determining the facts in cases. However, current legal methods have proved problematic to work with. This paper argues that, as a special model of public understanding of science, assessing expertise should consider source credibility of expertise from internal aspects, including scientific validity and reliability, and external aspects involving the credibility of experts. Using the Carneades Argumentation System we show that the internal and the external aspects are mediated by the structure of the argument from expert opinion with its matching set of critical questions

On a Razor\u27s Edge: Evaluating Arguments from Expert Opinion

This paper takes an argumentation approach to find the place of trust in a method for evaluating arguments from expert opinion. The method uses the argumentation scheme for argument from expert opinion along with its matching set of critical questions. It shows how to use this scheme in three formal computational argumentation models that provide tools to analyze and evaluate instances of argument from expert opinion. The paper uses several examples to illustrate the use of these tools. A conclusion of the paper is that from an argumentation point of view, it is better to critically question arguments from expert opinion than to accept or reject them based solely on trust

How to formalize informal logic

This paper presents a formalization of informal logic using the Carneades Argumentation System, a formal, computational model of argument that consists of a formal model of argument graphs and audiences. Conflicts between pro and con arguments are resolved using proof standards, such as preponderance of the evidence. Carneades also formalizes argumentation schemes. Schemes can be used to check whether a given argument instantiates the types of argument deemed normatively appropriate for the type of dialogue

Intelligent Practical Reasoning for Autonomous Agents: An Introduction

This paper is an introduction to recent work on practical (means-end, goal-direct ed) reasoning in artificial intelligence. By using an example of community deliberation concerning whether to change to a no-fault system of insurance, it is explained how practical reasoning is used in public deliberation. It is shown how argument mapping and argumentation schemes are useful tools for modeling the structure of the argumentation in such cases. The distinction between instrumental practical reasoning and value-based practical reasoning is modeled using argumentation schemes

Formalization of the ad hominem argumentation scheme

In this paper, several examples from the literature, and one central new one, are used as case studies of texts of discourse containing an argumentation scheme that has now been widely investigated in literature on argumentation. Argumentation schemes represent common patterns of reasoning used in everyday conversational discourse. The most typical ones represent defeasible arguments based on nonmonotonic reasoning. Each scheme has a matching set of critical questions used to evaluate a particular argument fitting that scheme. The project is to study how to build a formal computational model of this scheme for the circumstantial ad hominem argument using argumentation tools and systems developed in artificial intelligence. It is shown how the formalization built using these tools is applicable to the tasks of identification, analysis and evaluation of the central case studied. One important implication of the work is that it provides a foundational basis for showing how other argumentation schemes can be formalized