Assessing the Impact of Agents in Weighted Bipolar Argumentation Frameworks

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A defeasible logic programming with extra meta-level information through labels

Several argument-based formalisms have emerged with application in many areas, such as legal reasoning, intelligent web search, recommender systems, autonomous agents and multi-agent systems. In decision support systems, autonomous agents need to perform epistemic and practical reasoning; the first requiring reasoning about what to believe, and the latter, involving reasoning about what to do reaching decisions and, often, attaching more information to the pieces of knowledge involved. We will introduce an approach in the framework of DeLP called Argumentative Label Algebra (ALA), incorporating labels as a medium to convey meta-level information; through these labels it will represent different features of interest in the reasoning process, such as strength and weight measures, time availability, degree of reliability, etc. The labels associated with arguments will thus be combined and propagated according to argument interactions. This information can be used for different purposes: to carry information for a specific purpose, to determine which argument defeats another, analyzing a feature that is relevant to the domain, and to define an acceptability threshold which will determine if the arguments are strong enough to be accepted. The aim of this work is to improve the ability of representing real-world scenarios in argumentative systems by modeling different arguments attributes through labels.Varios formalismos basados en argumentos han emergido, con aplicaciones en muchas áreas, tales como el razonamiento legal, la búsqueda inteligente en la web, sistemas de recomendación, agentes autónomos y sistemas multi-agente. En los sistemas de soporte a la decisión, los agentes autónomos necesitan realizar razonamiento epistémico y práctico, el primero requiere razonamiento sobre qué creer, y el ´ultimo involucra razonamiento acerca de qué hacer, frecuentemente, agregando más información a las piezas de conocimiento involucradas. Introduciremos una aproximación en el marco de DeLP denominada Álgebra de Etiqueta para Argumentos (AEA), incorporando etiquetas como un medio para transmitir información de meta-nivel. A través de estas etiquetas se puede representar diferentes rasgos de interés en el proceso de razonamiento, tales como las medidas de peso y fuerza, disponibilidad de tiempo, grados de confiabilidad, etc. Las etiquetas asociadas con los argumentos podrán así ser combinadas y propagadas de acuerdo a las interacciones de los argumentos. Esta información puede ser usada para diferentes propósitos: llevar información para un objetivo específico, determinar cuáles argumentos derrotan a otros, analizar un rasgo que es relevante a un dominio, y definir un umbral de aceptabilidad que determinar´a si un argumento es lo suficientemente fuerte como para ser aceptado. El objetivo de este trabajo es mejorar la habilidad de representar escenarios del mundo real en sistemas argumentativos al modelar diferentes atributos de los argumentos a través de las etiquetas.Fil: Budan, Maximiliano Celmo David. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; Argentina. Universidad Nacional de Santiago del Estero; ArgentinaFil: Gomez Lucero, Mauro Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; ArgentinaFil: Simari, Guillermo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; Argentin

Interpretability of Gradual Semantics in Abstract Argumentation

International audiencergumentation, in the field of Artificial Intelligence, is a for-malism allowing to reason with contradictory information as well as tomodel an exchange of arguments between one or several agents. For thispurpose, many semantics have been defined with, amongst them, grad-ual semantics aiming to assign an acceptability degree to each argument.Although the number of these semantics continues to increase, there iscurrently no method allowing to explain the results returned by thesesemantics. In this paper, we study the interpretability of these seman-tics by measuring, for each argument, the impact of the other argumentson its acceptability degree. We define a new property and show that thescore of an argument returned by a gradual semantics which satisfies thisproperty can also be computed by aggregating the impact of the otherarguments on it. This result allows to provide, for each argument in anargumentation framework, a ranking between arguments from the most to the least impacting ones w.r.t a given gradual semantic

A Plausibility Semantics for Abstract Argumentation Frameworks

We propose and investigate a simple ranking-measure-based extension semantics for abstract argumentation frameworks based on their generic instantiation by default knowledge bases and the ranking construction semantics for default reasoning. In this context, we consider the path from structured to logical to shallow semantic instantiations. The resulting well-justified JZ-extension semantics diverges from more traditional approaches.Comment: Proceedings of the 15th International Workshop on Non-Monotonic Reasoning (NMR 2014). This is an improved and extended version of the author's ECSQARU 2013 pape

Labeled bipolar argumentation frameworks

An essential part of argumentation-based reasoning is to identify arguments in favor and against a statement or query, select the acceptable ones, and then determine whether or not the original statement should be accepted. We present here an abstract framework that considers two independent forms of argument interaction-support and conflict-and is able to represent distinctive information associated with these arguments. This information can enable additional actions such as: (i) a more in-depth analysis of the relations between the arguments; (ii) a representation of the user's posture to help in focusing the argumentative process, optimizing the values of attributes associated with certain arguments; and (iii) an enhancement of the semantics taking advantage of the availability of richer information about argument acceptability. Thus, the classical semantic definitions are enhanced by analyzing a set of postulates they satisfy. Finally, a polynomial-time algorithm to perform the labeling process is introduced, in which the argument interactions are considered.Fil: Escañuela Gonzalez, Melisa Gisselle. Universidad Nacional de Santiago del Estero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Budan, Maximiliano Celmo David. Universidad Nacional de Santiago del Estero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Simari, Gerardo. 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: Simari, Guillermo Ricardo. 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; Argentin

A Dynamic Model of Trust in Dialogues

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