3 Andrew Koster Jordi Sabater-Mir Marco Schorlemmer 2011 Meersman, Robert and Dillon, Tharam and Herrero, Pilar On the Move to Meaningful Internet Systems: OTM 2011. Hersonissos, Greece Springer 7044 182-199 Lecture Notes in Computer Science 14/10/2011 In open multi-agent systems trust is necessary to improve cooperation by enabling agents to choose good partners. Most trust models work by taking, in addition to direct experiences, other agents’ communicated evaluations into account. However, in an open multi-agent system other agents may use different trust models and as such the evaluations they communicate are based on different principles. This article shows that trust alignment is a crucial tool in this communication. Furthermore we show that trust alignment improves significantly if the description of the evidence, upon which a trust evaluation is based, is taken into account.