Comparison of six aggregation strategies to compute users' trustworthiness

The decision to grant trust in virtual societies is often an evidence based process. The evidence for such decision derives from a diverse set, where mutual relationships and contradictions might occur. This paper compares and evaluates six aggregation strategies to compute users' trustworthiness. Our evaluation performed over a large online-community, shows how a rule-based strategy based on an argumentation semantic outperforms strategies where mutual relationships among evidence are ignored.