Substantive irrationality in cognitive systems

International audienceIn this paper we approach both procedural and substantive irrationality of artificial agent cognitive systems and consider that when it is not possible for an agent to make a logical inference (too expensive cognitive effort or not enough knowledge) she might replace certain parts of the logical reasoning with mere associations

Towards an Understanding of Human Persuasion and Biases in Argumentation (CAF 2016)

International audienceWe present in this paper some recent work aiming at allowing the formal analysis of the persuasive impact that an argument may produce on a human agent based. We present a computational model based on the Dual Process Theory and applied to argument evaluation. These works form the preliminary step that will allow a better understanding of two crucial aspects of collective decision-making: persuasive processes and argumentation strategies

Raisonnement défaisable dans les règles existentielles

Knowledge representation and reasoning on the Semantic Web has recently focused, due to practical rationale, on the subset of first order logic called existential rules. In this thesis we investigate reasoning with existential rules in presence of conflicting information and introduce defeasible existential rule reasoning. We provide three main salient results as follows. First we show that classical defeasible reasoning techniques need to be revisited for existential rules and study their theoretical and implementation related challenges. Second, we provide a new combinatorial structure that allows for diverse variants of defeasible reasoning to be captured together and study its expressivity and versatility. Third we evaluate our work with respect to the state of the art in inconsistency handling in existential rules and investigate the human appeal of such reasoning techniques.La représentation des connaissances et le raisonnement sur le Web sémantique se sont récemment concentrés, pour des raisons pratiques, sur le sous-ensemble de la logique du premier ordre appelé règles existentielles. Dans cette thèse, nous étudions le raisonnement avec des règles existentielles en présence d'informations contradictoires et introduisons un raisonnement existentiel défaisible. Nous proposons trois résultats principaux: Premièrement, nous montrons que les techniques de raisonnement défaisibles classiques doivent être revisitées pour les règles existentielles et étudions leurs défis théoriques et de mise en œuvre. Deuxièmement, nous fournissons une nouvelle structure combinatoire qui permet de capturer diverses variantes du raisonnement défaisable et étudions son expressivité et sa polyvalence. Troisièmement, nous évaluons notre travail par rapport à l'état de l'art dans le traitement des incohérences et des inconsistances dans les règles existentielles et étudions l'intérêt humain de telles techniques de raisonnement

Demonstrating a benchmark for defeasible reasoning

International audienceIn this demonstration we focus on the task of a data engineer choosing what tool to perform defeasible reasoning with a first order logic knowledge base

On a Flexible Representation for Defeasible Reasoning Variants

International audienceWe propose Statement Graphs (SG), a new logical formalism for defeasible reasoning based on argumentation.Using a flexible labeling function, SGs can capture the variants of defeasible reasoning (ambiguity blocking or propagating, with or without team defeat, and circular reasoning). We evaluate our approach with respect to human reasoning and propose a working first order defeasible reasoning tool that, compared to the state of the art, has richer expressivity at no added computational cost. Such tool could be of great practical use in decision making projects such as H2020 NoAW

Argumentation-Based Defeasible Reasoning For Existential Rules

International audienceLogic based argumentation allows for defeasible reasoning over monotonic logics via grounded semantics or defeasible logic programming (DeLP). We investigate the practical implementation of such techniques for existential rules, a logical language used by many Semantic Web and Ontology Based Data Access applications. Existing tools in the literature (ASPIC+, DeLP) perform poorly for such languages due to their choice of generic reasoning methods using resolution. Since existential rules account for weak negation (as opposed to more general languages) we claim that state of the art argumentation methods (ASPIC+ or DeLP) could be practically outperformed by dedicated forward chaining methods. We analyse this problem from a theoretical point of view, especially with regards to forward chaining issues such as derivation loss, and perform a series of experiments to empirically evaluate our performance claims

DAMN: Defeasible Reasoning Tool for Multi-Agent Reasoning

International audienceThis demonstration paper introduces DAMN: a defeasible reasoning platform available on the web. It is geared towards decision making where each agent has its own knowledge base that can be combined with other agents to detect and visualize conflicts and potentially solve them using a semantics. It allows the use of different defeasible reasoning semantics (ambiguity blocking/propagating with or without team defeat) and integrates agent collaboration and visualization features

On the Chase for All Provenance Paths with Existential Rules

In this paper we focus on the problem of how lineage for existential rules knowledge bases. Given a knowledge base and an atomic ground query, we want to output all minimal provenance paths of the query (i.e. the sequence of rule applications that generates an atom from a given set of facts). Obtaining all minimal provenance paths of a query using forward chaining can be challenging due to the simplifications done during the rule applications of different chase mechanisms. We build upon the notion of Graph of Atoms Dependency (GAD) and use it to solve the problem of provenance path loss in the context of forward chaining with existential rules. We study the properties of this structure and investigate how different chase mechanisms impact its construction

An empirical evaluation of argumentation in explaining inconsistency tolerant query answering

International audienceIn this paper we answer empirically the following research question: " Are dialectical explanation methods more effective than one-shot explanation methods for Intersection of Closed Repairs inconsistency tolerant semantics in existential rules knowledge bases? " We ran two experiments with 84 and respectively 38 participants and showed that under certain conditions dialectical approaches are significantly more effective than one-shot explanations

Extending GWAPs for Building Profile Aware Associative Networks

International audienceAssociative networks have been long used as a way to provide intelligent machines with a working memory and applied in various domains such as Natural Language Processing or customer associations analysis. While giving out numerous practical advantages, existing Games With a Purpose (GWAPs) for eliciting associative networks cannot be employed in certain domains (for example in customer associations analysis) due to the lack of profile based filtering. In this paper we ask the following research question: “Does considering agents profile information when constructing an associative network by a game with a purpose allows to extract subjective information that might have been lost otherwise?”. In order to answer this question we present the KAT (Knowledge AcquisiTion) game that extends upon the state of the art by considering agent profiling. We formalise the game, implement it and carry out a pilot study that validates the above mentioned research hypothesis