This paper proposes an approach to investigate norm-governed learning agents which combines a logic-based formalism with an equation-based counterpart. This dual formalism enables us to describe the reasoning of such agents and their interactions using argumentation, and, at the same time, to capture systemic features using equations. The approach is applied to norm emergence and internalisation in systems of learning agents. The logical formalism is rooted into a probabilistic defeasible logic instantiating Dung’s argumentation framework. Rules of this logic are attached (...) with probabilities to describe the agents’ minds and behaviours as well as uncertain environments. Then, the equation-based model for reinforcement learning, defined over this probability distribution, allows agents to adapt to their environment and self-organise. (shrink)

The behaviour of autonomous agents may deviate from that deemed to be for the good of the societal systems of which they are a part. Norms have therefore been proposed as a means to regulate agent behaviours in open and dynamic systems, where these norms specify the obliged, permitted and prohibited behaviours of agents. Regulation can effectively be achieved through use of enforcement mechanisms that result in a net loss of utility for an agent in cases where the agent’s behaviour (...) fails to comply with the norms. Recognition of compliance is thus crucial for achieving regulation. In this paper, we propose a general framework for observation of agents’ behaviour, and recognition of this behaviour as constituting, or counting as, compliance or violation. The framework deploys monitors that receive inputs from trusted observers, and processes these inputs together with transition network representations of individual norms. In this way, monitors determine the fulfillment or violation status of norms. The paper also describes a proof of concept implementation of the framework, and its deployment in electronic contracting environments. (shrink)

The regulation of the activity of multiple autonomous entities represented in a multi-agent system, in environments with no central design (and thus with no cooperative assumption), is gaining much attention in the research community. Approaches to this concern include the use of norms in so-called normative multi-agent systems and the development of electronic institution frameworks. In this paper we describe our approach towards the development of an electronic institution providing an enforceable normative environment. Within this environment, institutional services are provided (...) that assist agents in forming cooperative structures whose commitments are made explicit through contracts. Our normative framework borrows some concepts from contract law theory. Contracts are formalized using norms which are used by the institution while monitoring agents’ activities, thus making our normative environment dynamic. We regard the electronic institution as a means to facilitate both the creation and the enforcement of contracts between agents. A model of “institutional reality” is presented that allows for monitoring the fulfillment of norms. The paper also distinguishes our approach from other developments of the electronic institution concept. We address the application of our proposal in the B2B field, namely regarding the formation of Virtual Organizations. (shrink)

The importance of potential intentions has been demonstrated both in the construction of agent systems and in the formalisation of teamwork behaviour. However, there still lacks an adequate semantics for the notion of potential intentions as introduced by Grosz and Kraus in their SharedPlans framework. In this paper, we give a formal semantics to intentions and potential intentions, drawing upon both the representationalist approach and the accessibility-based approach. The model captures the dynamic relationship among intentions and potential intentions by providing (...) semantic rules and conditions. Also, the model treats norms as a special class of intentional context, and it is shown that norms play a critical role in the dynamics of intentions in multiagent systems. The formal semantics allows us to validate some properties that are widely-accepted for intention attitudes. (shrink)