Revisiting Approximate Reasoning Based on Grounded Semantics

Efficient computation of hard reasoning tasks is a key issue in abstract argumentation. One recent approach consists in defining approximate algorithms, i.e. methods that provide an answer that may not always be correct, but outperforms the exact algorithms regarding the computation runtime. One such approach proposes to use the grounded semantics, which is polynomially computable, as a starting point for determining whether arguments are (credulously or skeptically) accepted with respect to various semantics. In this paper, we push further this idea by defining various approaches to evaluate the acceptability of arguments which are not in the grounded extension, neither attacked by it. We have implemented our approaches, and we describe the result of their empirical evaluation.