WG4 Workshop in Paris


As part of the 4th Joint Working Group Workshops WG4 has organised two sessions:

1) Argumentation and Negotiation

Tuesday, Dec. 14th , 2.30 - 4pm

Chair: Sanjay Modgil


2.15 : Leila Amgoud

Title : A formal analysis of logic-based argumentation systems

Abstract :

Dung’s abstract argumentation model consists of a set of arguments and a binary relation
encoding attacks among arguments. Different acceptability semantics have been defined for
evaluating the arguments. What is worth noticing is that the model completely abstracts
from the applications to which it can be applied. Thus, it is not clear what are the
results that can be returned in a given application by each semantics.
This paper answers this question. For that purpose, we start by
plunging the model in a real application. That is, we assume that we have an inconsistent
knowledge base (KB) containing formulas of an abstract monotonic logic. From this
base, we show how to define arguments. Then, we characterize the different semantics in
terms of the subsets of the KB that are returned by each extension. We show a full
correspondence between maximal consistent subbases of a KB and maximal conflict-free
sets of arguments. We show also that stable and preferred extensions choose randomly
some consistent subbases of a base. Finally, we investigate the results of three
argumentation systems that use well-known attack relations.

2.35 : Sindhu Joseph

Title : Coherence-based argumentation models for normative agents

Abstract :

In this talk coherence-based models are proposed as an alternative to argumentation models
for the reasoning of normative agents and normative deliberation. The model is based on
Thagards’s theory of cognitive coherence and exploits the coherence relations that exist
between claims and conclusion of arguments. A coherence-based model is intended to
introduce more flexibility in the process of deliberation and agreement generation among
normative agents. The basic coherence philosophy and what makes it interesting in the
context of normative agents that deliberate to regulate a domain of interest are discussed.

2.55 : Nabila Hadidi

Title : On argumentation-based negotiation

Abstract : In this talk we present an argumentative version of the well known alternating
offers negotiation protocol. Moreover we analyze the argumentation based reasoning mechanism
used by the agents for negotiating based on both epistemic and practical arguments and we
discuss some strategic issues.

3.15 : Nicolas Maudet

Title (TBA)

Abstract (TBA)

3.30 : Wrap up and general discussion

Location Paris Descartes University , 45 rue des Saints-Pères Room Lavoisier A

2) Argumentation and Trust

Wednesday, Dec. 15th , 11.30 - 1pm

Chair: Francesca Toni


Simon Parsons

Title : A system of argumentation for reasoning about trust

Abstract :

Trust is a mechanism for managing the uncertainty about autonomous
entities and the information they store, and so can play an important
role in any decentralized system. As a result, trust has been widely
studied in multiagent systems and related fields such as the semantic
web. In this talk I introduce a formal system of argumentation that can
be used to reason about trust, explore some of its properties
and illustrate its application on a benchmark problem from the trust

Pierpaolo Dondio

Title : Trust As a Form of Defeasible Reasoning

Abstract  :

Computational models of trust have emerged in the last decade with the aim
of exploting the notion of trust in virtual societies. Nevertheless, few limited models compute trust
level as a result of a reasoning process composed by rules and patterns peculiar to trust. The talk
describes a model of trust/reputation based on defeasible reasoning and knowledge engineering.
The model considers the action of evaluating entity’s trustworthiness an argumentation process.
The form of such argumentation is represented by a defeasible reasoning semantic and by the notion
of trust scheme, the specialized version of the general notion of argumentation scheme. A presumptive
reasoning framework is used to assess the plausibility of each scheme via a set of critical questions.
A knowledge-based model of trust, as it emerges from social science, provides the content of each
trust scheme. The system builds the arguments of its reasoning by mapping trust schemes over available
application data, and by quantifying each argument for a specific trustee using a rank-based statistics.
The model has been applied to a large set of Web 2.0 applications such as Wikis and Online Communities,
particularly finance-related forums.”

Paolo Torroni

Title : Arguing for a new social Web

Abstract :

We are spending more and more time on the Social Web. If we
are looking for information and feedback, we can refer to social
communities, such as Facebook and Twitter, participatory journalism Web
sites, such as the Huffington Post, and uncountable discussion fora on
general and specialized topics. However, while promoting freedom of
speech and content sharing, the Social Web gives up from trustworthiness
of information sources, dependability as a discussion platform,
robustness against trolling and other kinds of attacks, and
authoritativeness. A combination of social community tools,
computational argumentation technologies and social voting could be the
key for tomorrow’s way of thinking, finding, evaluating, proposing,
sharing information in the Web.

Location Paris Descartes University , 45 rue des Saints-Pères Room Lavoisier A