Recommending Services in a Trust-Based Decentralized User Modeling System

Trust and reputation mechanisms are often used in peer-to-peer networks, multi-agent systems and online communities for trust-based interactions among the users. Trust values are used to differentiate among members of the community as well as to recommend a service provider. Although different users have different needs and expectations in different aspects of the service providers, traditional trust-based models do not use trust values on neighbors for judging different aspects of service providers. In this paper, we use a multi-faceted trust model where each agent has two sets of trust values: i) trust on different aspects of the quality of service providers, ii) trust on recommendations provided for these aspects. These trust models are used in a decentralized user modeling system where agents have different preference weights in three different criteria of service providers. We have done a simulation of this system that recommends the best possible service provider for each agent according to its preference model. To the best of our knowledge this is the first system that uses multi-faceted trust values both on the qualities of service-providers and on other users’ ability to evaluate these qualities of service providers in a decentralized user modeling system.