Defeasible Argumentation of Software Architectures

Defeasible argumentation is typical of legal and scientific reasoning. A defeasible argument is one in which the conclusion can be accepted tentatively in relation with the evidence known so far, but may need to be retracted as new evidence comes in. This paper analyses the role of defeasible argumentation in the explanation and evaluation of architectural decisions. We analyse technical explanations offered by engineers at Twitter and eBay about several architectural decisions adopted in those systems. We generalize these examples in four argumentation schemes. We also study the typical case of reasoning with a formal model of an architecture, and we infer a fifth argumentation scheme. Finally, we apply Hastings’ method of attaching a set of critical questions to each scheme. We show that the existence of critical questions reveals that the inferred schemes are defeasible: in argumentation theory, if a respondent asks one of the critical questions matching a scheme and the proponent of an argument fails to offer an adequate answer, the argument defaults and the conclusion is retracted. This dialogical structure is the basis of typical architectural evaluations. We conclude that the provided evidence supports the hypothesis that defeasible argumentation is employed in architectural evaluation. In this context, a rich catalogue of argumentation schemes is a useful tool for the architect to organize his or her reasoning; critical questions assist the architect in identifying the weak points of his or her explanations, and provide the evaluation team with a checklist of issues to be raised.Universidad de Sevilla VPPI-U

Formalizing argument-based agent interaction in electronic institutions

During the last decade the notion of agent has gained acceptance within the AI community, mainly due to its adequacy to formalize complex environments. Agents can be thought as active software objects, which may be autonomous and able to perceive, reason, act, and interact with other agents. When agents interact with each other, a multi-agent system (MAS) arises.Eje: Inteligencia Artificial Distribuida, Aspectos Teóricos de la Inteligencia Artificial y Teoría de la ComputaciónRed de Universidades con Carreras en Informática (RedUNCI

Argument-based Applications to Knowledge Engineering

Argumentation is concerned with reasoning in the presence of imperfect information by constructing and weighing up arguments. It is an approach for inconsistency management in which conflict is explored rather than eradicated. This form of reasoning has proved applicable to many problems in knowledge engineering that involve uncertain, incomplete or inconsistent knowledge. This paper concentrates on different issues that can be tackled by automated argumentation systems and highlights important directions in argument-oriented research in knowledge engineering. 1 Introduction One of the assumptions underlying the use of classical methods for representation and reasoning is that the information available is complete, certain and consistent. But often this is not the case. In almost every domain, there will be beliefs that are not categorical; rules that are incomplete, with unknown or implicit conditions; and conclusions that are contradictory. Therefore, we need alternative know..

Defeasible decision making in a robotic environment

Decision making models for autonomous agents are recently receiving increased attention, particularly in the feld of intelligent robots. This work presents a Defeasible Logic Programming approach to decision making in an environment with single and multiple robots. We will show, how a successful tool for knowledge representation and defeasible reasoning could be applied to the problem of deciding which task should be performed next. Besides, we will explain with detailed examples how the decision process is performed when there is only one robot in the environment, and then we will consider how the same robot decides when there are more robots working in the environment.Actualmente, los modelos de toma de decisiones para agentes autónomos están recibiendo mucha atención, particularmente en el área de robots inteligentes. Este trabajo presenta un enfoque basado en Programación en Lógica Rebatible para la toma de decisiones en un ambiente con un único robot y con múltiples robots. Mostraremos como una herramienta exitosa para la representación de conocimiento y razonamiento rebatible, puede ser aplicada al problema de decidir que tarea debe ser realizada a continuación. Además, explicaremos con ejemplos detallados como se realiza el proceso de decisión cuando hay solamente un robot en el ambiente, y luego consideraremos como decide el mismo robot cuando hay otros robots presentes en el ambiente.VIII Workshop de Procesamiento Distribuido y ParaleloRed de Universidades con Carreras en Informática (RedUNCI

Logic-based Technologies for Intelligent Systems: State of the Art and Perspectives

Together with the disruptive development of modern sub-symbolic approaches to artificial intelligence (AI), symbolic approaches to classical AI are re-gaining momentum, as more and more researchers exploit their potential to make AI more comprehensible, explainable, and therefore trustworthy. Since logic-based approaches lay at the core of symbolic AI, summarizing their state of the art is of paramount importance now more than ever, in order to identify trends, benefits, key features, gaps, and limitations of the techniques proposed so far, as well as to identify promising research perspectives. Along this line, this paper provides an overview of logic-based approaches and technologies by sketching their evolution and pointing out their main application areas. Future perspectives for exploitation of logic-based technologies are discussed as well, in order to identify those research fields that deserve more attention, considering the areas that already exploit logic-based approaches as well as those that are more likely to adopt logic-based approaches in the future

Reasoning about intentions: a defeasible argumentation approach

In this work we present an approach to model an action-oriented system controlled by BDI agents using a defeasible argumentation formalism to represent its knowledge. Here, our main concern will be modelling the software agents that drive the physical robots. The chosen agent architecture will be BDI and it will use defeasible argumentation to perform the reasoning part of the system. Provided that our laboratory has the basic setup to implement a robotic soccer team, that is the application domain selected to test this approach.VI Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Logic-based Technologies for Multi-agent Systems: A Systematic Literature Review

Precisely when the success of artificial intelligence (AI) sub-symbolic techniques makes them be identified with the whole AI by many non-computerscientists and non-technical media, symbolic approaches are getting more and more attention as those that could make AI amenable to human understanding. Given the recurring cycles in the AI history, we expect that a revamp of technologies often tagged as “classical AI” – in particular, logic-based ones will take place in the next few years. On the other hand, agents and multi-agent systems (MAS) have been at the core of the design of intelligent systems since their very beginning, and their long-term connection with logic-based technologies, which characterised their early days, might open new ways to engineer explainable intelligent systems. This is why understanding the current status of logic-based technologies for MAS is nowadays of paramount importance. Accordingly, this paper aims at providing a comprehensive view of those technologies by making them the subject of a systematic literature review (SLR). The resulting technologies are discussed and evaluated from two different perspectives: the MAS and the logic-based ones

Solving Power and Trust Conflicts through Argumentation in Agent-mediated Knowledge Distribution

Distributing pieces of knowledge in large, usually distributed organizations is a central problem in Knowledge and Organization management. Policies for distributing knowledge and information are mostly incomplete or in potential conflict with each other. As a consequence, decision processes for information distribution may be difficult to formalize on the basis of a rationally justified procedure. This article presents an argumentative approach to cope with this problem based on integrating the JITIK multiagent system with Defeasible Logic Programming (DeLP), a logic programming formalism for defeasible argumentation. We show how power relations, as well as delegation and trust, can be embedded within our framework in terms of DeLP, in such a way that a dialectical argumentation process works as a decision core. Conflicts among policies are solved on the basis of a dialectical analysis whose outcome determines to which specific users different pieces of knowledge are to be delivered.Fil: Chesñevar, Carlos Iván. Universitat de Lleida; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Brena, Ramón. Centro de Sistemas Inteligentes, Tecnológico de Monterrey; MéxicoFil: Aguirre, José L.. Centro de Sistemas Inteligentes, Tecnológico de Monterrey; Méxic

An architecture for rational agents interacting with complex environments

In this paper we sketch an agent architecture suitable to be used as a tool for exploring agent perception and multiagent interaction. Nowadays, there is no strict correspondence between the theoretical work in rational agents and their implementation. In this respect, it is our intention to reach a good trade-off between expressiveness and implementability.Eje: Inteligencia artificialRed de Universidades con Carreras en Informática (RedUNCI