Natalia Criado

Open issues for normative multi-agent systems

A challenging problem currently addressed in the multi-agent systems area is the development of open systems; which are characterized by the heterogeneity of their participants and the dynamic features of both their participants and their environment. The main feature of agents in these systems is autonomy. It is this autonomy that requires regulation, and norms are a solution for this. Norms represent a tool for achieving coordination and cooperation among the members of a society. They have been employed in the field of Artificial Intelligence as a formal specification of deontic statements aimed at regulating the actions of software agents and the interactions among them. This article gives an overview of the most relevant works on norms for multi-agent systems. This review considers open multi-agent systems challenges and points out the main open questions that remain in norm representation, reasoning, creation, and implementation.

Designing Virtual Organizations

Virtual Organizations are a suitable mechanism for enabling coordination of heterogeneous agents in open environments. Taking into account many concepts of the Human Organization Theory, a model for Virtual Organizations has been developed. This model describes the structural, functional, normative and environmental aspects of the system. It is based on four main concepts: organizational unit, service, norm and environment. All these concepts have been applied in a case-study example for the management of a travel agency system.

A distributed architecture for enforcing norms in open MAS

Norms have been promoted as a coordination mechanism for controlling agent behaviours in open MAS. Thus, agent platforms must provide normative support, allowing both norm-aware and non norm-aware agents to take part in MAS controlled by norms. In this paper, the most relevant proposals on the definition of norm enforcement mechanisms have been analysed. These proposals present several drawbacks that make them unsuitable for open MAS. In response to these problems, this paper describes a new Norm-Enforcing Architecture aimed at controlling open MAS.

A norm-based organization management system

Virtual organizations are conceived as an effective mechanism for ensuring coordination and global goal fulfilment of an open system, in which heterogeneous entities (agents or services) interact and might also present self-interested behaviours. However, available tools rarely give support for organizational abstractions. The THOMAS multi-agent architecture allows the development of open multi-agent applications. It provides a useful framework for the development of virtual organizations, on the basis of a service-based approach. In this paper, the Organization Management System component of the THOMAS architecture is presented. It is in charge of the organization life-cycle process, including the normative management. It provides a set of structural, informative and dynamic services, which allow describing both specification and administration features of the structural elements of the organization and their dynamics. Moreover, it makes use of a normative language for controlling the service request, provision and register.

Normative deliberation in graded BDI agents

Norms have been employed as a coordination mechanism for Open MAS, but to become effective, they must be internalized by agents; i.e. these agents must be able to accept norms while maintaining their autonomy. Nevertheless, traditional BDI agent architectures only represent beliefs, intentions and desires. In this paper, the multicontext BDI agent architecture has been extended with a recognition context and a normative context in order to allow agents to acquire norms from their environment and consider norms in their decisions.

Implicit Contextual Integrity in Online Social Networks

Many real incidents demonstrate that users of Online Social Networks need mechanisms that help them manage their interactions by increasing the awareness of the different contexts that coexist in Online Social Networks and preventing them from exchanging inappropriate information in those contexts or disseminating sensitive information from some contexts to others. Contextual integrity is a privacy theory that conceptualises the appropriateness of information sharing based on the contexts in which this information is to be shared. Computational models of Contextual Integrity assume the existence of well-defined contexts, in which individuals enact pre-defined roles and information sharing is governed by an explicit set of norms. However, contexts in Online Social Networks are known to be implicit, unknown a priori and ever changing; users relationships are constantly evolving; and the information sharing norms are implicit. This makes current Contextual Integrity models not suitable for Online Social Networks.In this paper, we propose the first computational model of Implicit Contextual Integrity, presenting an information model for Implicit Contextual Integrity as well as a so-called Information Assistant Agent that uses the information model to learn implicit contexts, relationships and the information sharing norms in order to help users avoid inappropriate information exchanges and undesired information disseminations. Through an experimental evaluation, we validate the properties of the model proposed. In particular, Information Assistant Agents are shown to: (i) infer the information sharing norms even if a small proportion of the users follow the norms and in presence of malicious users; (ii) help reduce the exchange of inappropriate information and the dissemination of sensitive information with only a partial view of the system and the information received and sent by their users; and (iii) minimise the burden to the users in terms of raising unnecessary alerts.

Norm enforceability in electronic institutions

Nowadays Multi-Agent Systems require more and more regulation and normative mechanisms in order to assure the correct and secure execution of the interactions and transactions in the open virtual organization they are implementing. The Electronic Institution approach for developing Multi-Agent Systems implements some enforceability mechanisms in order to control norms execution and observance. In this paper we study a complex situation in a regulated environment in which the enforceability mechanisms provided by the current Electronic Institutions implementation cannot deal appropriately with norm observance. The analyzed situation is exemplified with a specific scenario of the mWater regulated environment, an electronic market for water-rights transfer. After this example is presented, we extrapolate it to a more generic domain while also addressing the main issues for its application in general scenarios.

THOMAS: An agent platform for supporting normative multi-agent systems

(TIN2009-13839-C03-01) project of the Spanish government; Valencian Prometeo project (2008/051); and CONSOLIDER-INGENIO 2010 under grant (CSD2007-00022); FPU grant (AP-2007-01256 awarded to Natalia Criado).

Human-inspired model for norm compliance decision making

One of the main goals of the agent community is to provide a trustworthy technology that allows humans to delegate some specific tasks to software agents. Frequently, laws and social norms regulate these tasks. As a consequence agents need mechanisms for reasoning about these norms similarly to the user that has delegated the task to them. Specifically, agents should be able to balance these norms against their internal motivations before taking action. In this paper, we propose a human-inspired model for making decisions about norm compliance based on three different factors: self-interest, enforcement mechanisms and internalized emotions. Different agent personalities can be defined according to the importance given to each factor. These personalities have been experimentally compared and the results are shown in this article.

Rational strategies for norm compliance in the n-BDI proposal

Norms represent an effective tool for achieving coordination and cooperation among members of open systems. However, agents must be able to adopt norms autonomously. In this sense, the n-BDI proposal is a BDI agent architecture which has been extended in order to allow agents to comply with norms autonomously. Compliance with norms can be explained by both rational and non-rational motivations. Rational motivations consider the influence of norm compliance and violation on agents goals. In this work the implementation of rational strategies for making a decision about norm compliance in the n-BDI architecture is described.