Gradual Semantics Accounting for Similarity between Arguments

Argumentation is a reasoning model based on the justification of claims by arguments. Often, arguments to be considered are not completely independent, two arguments can be related for different reasons, they may overlap, or given by two persons that make similar statements during a debate, but express them differently, etc. This paper studies for the first time the impact of similarity (i.e., when pairs of arguments are related) in the context of gradual evaluation in abstract ar-gumentation. We present principles that a semantics accounting for similarities should satisfy, and show how to extend gradual semantics for this purpose. We propose three original methods to do so, and study their properties. In particular, the new semantics are evaluated with respect to the new principles , and others from the literature.