Joana Urbano

Bio: Joana Urbano is an academic researcher from University of Porto. The author has contributed to research in topics: Computational trust & Multi-agent system. The author has an hindex of 9, co-authored 25 publications receiving 238 citations. Previous affiliations of Joana Urbano include Faculdade de Engenharia da Universidade do Porto.

Computing Confidence Values: Does Trust Dynamics Matter?

Abstract: Computational Trust and Reputation (CTR) systems are platforms capable of collecting trust information about candidate partners and of computing confidence scores for each one of these partners. These systems start to be viewed as vital elements in environments of electronic institutions, as they support fundamental decision making processes, such as the selection of business partners and the automatic and adaptive creation of contractual terms and associated enforcement methodologies. In this article, we propose a model for the aggregation of trust evidences that computes confidence scores taking into account dynamic properties of trust. We compare our model with a traditional statistical model that uses weighted means to compute trust, and show experimental results that show that in certain scenarios the consideration of the trust dynamics allows for a better estimation of confidence scores.

ANTE: Agreement Negotiation in Normative and Trust-Enabled Environments

Abstract: The ANTE framework encompasses results of research efforts on three main agreement technology concepts, namely negotiation, normative environments and computational trust ANTE has been conceived as a general framework with a wide range of applications in mind This chapter provides an overview of the main guidelines of this project, and explores two application domains for this framework: automated B2B electronic contracting, and disruption management in the context of an airline company operational control

A Socio-cognitive Perspective of Trust

Abstract: Trust and reputation are two distinct social constructs of high complexity that have been studied for decades in different areas of knowledge. In order to allow for efficient models of computational trust and reputation, one must first understand the nature and dynamics of each one of these constructs. In this chapter, we focus on the social and cognitive aspects of the trust concept, and overview its fundamental characteristics, such as its determinants, nature, and dynamics. Then, we present two distinct hypothesis one can state for the interplay between trust and reputation: either reputation is an antecedent of trust, or both are considered as two distinct contributions to the ultimate decision making process. If they are seen as isolated components, trust is no longer directly influenced by reputation. Finally, we briefly refer to current existing computational trust models, including those that integrate the management of computational reputation.

Engaging the dynamics of trust in computational trust and reputation systems

Abstract: Computational Trust and Reputation (CTR) systems are essential in electronic commerce to encourage interactions and suppress deceptive behaviours. This paper focus on comparing two different kinds of approaches to evaluate the trustworthiness of suppliers. One is based on calculating the weighted mean of past results. The second one applies basic properties of the dynamics of trust. Different scenarios are investigated, including a more problematic one that results from introducing newcomers during the simulation. Experimental results presented in this paper prove the benefits of engaging properties of the dynamics of trust in CRT systems, as it noticeably improves the process of business partners' selection and increases the utility.

Making electronic contracting operational and trustworthy

Abstract: An Electronic Institution includes a normative environment with rules and norms for agents' interoperability, and is also a service providing platform that assists agents in the task of establishing and conducting normative relationships (contracts). Using this platform, agents representing organizations willing to engage in a collective contractual activity select partners according to different factors, including their capabilities, current business needs and information on past business experiences that may be used as inputs to trust building. In our framework we have designed a tightly coupled connection between electronic contract monitoring and a computational trust model. In this paper, we explain the rationale behind this connection and detail how it is materialized. In particular, we explain how our situation-aware trust model relies on past contractual behavior to dynamically build up a trustworthiness image of each agent that can be helpful for future encounters. Experiments with simplified scenarios show the effectiveness of our approach.

Trust, Power and Control in Trans-Organizational Relations. Working Paper WP 129 (6/99)

Abstract: This paper analyzes trust and power as means of co-ordinating trans-organizational relationships. It is argued that, depending on the institutional environment, there are two distinct patterns of controlling relationships, where trust and power are interrelated in quite different ways. First, both mechanisms are generated at the inter-personal level and either trust or power dominates the relationship. Second, power occurs at the level of the structural framework of relationships and is highly conducive to developing trust between individual organizations. Thus, specific forms of trust and power are identified and the institutional environment is viewed as playing a crucial role in shaping the quality of trans-organizational relations. The theoretical background of the paper mainly draws on conceptual ideas of Systems Theory, Structuration Theory and New Institutionalism