A Heuristic Pruning Technique for Dialectical Trees on Argumentation-Based Query-Answering Systems

Arguments in argumentation-based query-answering systems can be associated with a set of evidence required for their construction. This evidence might have to be retrieved from external sources such as databases or the web, and each attempt of retrieving a piece of evidence comes with an associated cost. Moreover, a piece of evidence may be available at one moment but not at others, and this is not known beforehand. As a result, the set of active arguments (whose entire set of evidence is available) that can be used by the argumentation machinery of the system may vary from one scenario to another. In this work we propose a heuristic pruning technique for building dialectical trees in argumentation-based query-answering systems, with the aim of minimizing the cost of retrieving the pieces of evidence associated with the arguments that need to be accounted for in the reasoning process.