Adaptiveness and Social-Compliance in Trust Management. A Multi-Agent Based Approach

Virtual communities (VCs) are socio-technical systems wherein distributed individuals (human and/or artificial) are grouped together around common objectives and goals [10, 6]. In such systems, participants are massively collaborating with each others by sharing their private resources and knowledge. A collaboration always bears the risk that one partner exhibits uncooperative or malicious behaviour. Thus trust is a critical issue for the success of such systems. In human-based virtual communities, participants rely on a various set of information while assessing their degree of trust in each others. That information represent, in most of the situations, descriptions of partners properties on which constraints are specified to distinguish trustworthy partners from untrustworthy ones. These constraints are expressed by means of trust policies and constitute the individual’s trust requirements. Such policies are often made implicit as there is no need for humans to make them explicit. But in our investigations, we are more interested in agent-based virtual communities where participants are assisted by software agents that behave on their behalf [11]. In such settings, participants must be able to explicitly specify the trust policies their agents should rely on to derive trust. For that purpose, trust policy languages represent a formal and flexible interface between the human and its agent in the virtual community [13]. The work presented in this dissertation addresses the problem of trust management in open and decentralised virtual communities (VCs). We address this problem by proposing an Adaptive and Socially-Compliant Trust Management System (ASC-TMS) adopting a multi-agent based approach. Our proposal relies on the joint use of adaptive trust policies and adaptation meta-policies, which allow VCs members to make adaptive and socially-compliant trust decisions.