Epistemic Graphs for Representing and Reasoning with Positive and Negative Influences of Arguments.

This paper introduces epistemic graphs as a generalization of the epistemicapproach to probabilistic argumentation. In these graphs, an argument can bebelieved or disbelieved up to a given degree, thus providing a morefine--grained alternative to the standard Dung's approaches when it comes todetermining the status of a given argument. Furthermore, the flexibility of theepistemic approach allows us to both model the rationale behind the existingsemantics as well as completely deviate from them when required. Epistemicgraphs can model both attack and support as well as relations that are neithersupport nor attack. The way other arguments influence a given argument isexpressed by the epistemic constraints that can restrict the belief we have inan argument with a varying degree of specificity. The fact that we can specifythe rules under which arguments should be evaluated and we can includeconstraints between unrelated arguments permits the framework to be morecontext--sensitive. It also allows for better modelling of imperfect agents,which can be important in multi--agent applications.