Given many sources of information asserting different things, deciding to accept or not a belief can become a complicated task. Seeing the problem from the source's point of view, it would be interesting to understand what are the variables influencing the final outcome, in order to manipulate them in the most convenient way: it could be easiest to attack or support another source rather than just report an information. The basic idea in this work is to propose a novel systematic approach to beliefs' argumentation. Exploiting the concept of trust, we designed and implemented a theoretical and computational model that identifies all the variables
playing a role when an agent has to evaluate whether to accept or not a given belief. According to us, once identified these factors, all the argumentations to support or to deny the belief have to deal with them. Then we present a list of some possible argumentative manoeuvres to show how the framework works.
