A Rule-Based System for Unrestricted Bridging Resolution: Recognizing Bridging Anaphora and Finding Links to Antecedents

Bridging resolution plays an important role in establishing (local) entity coherence. This paper proposes a rule-based approach for the challenging task of unrestricted bridging resolution, where bridging anaphors are not limited to definite NPs and semantic relations between anaphors and their antecedents are not restricted to meronymic relations. The system consists of eight rules which target different relations based on linguistic insights. Our rule-based system significantly outperforms a reimplementation of a previous rule-based system (Vieira and Poesio, 2000). Furthermore, it performs better than a learning-based approach which has access to the same knowledge resources as the rule-based system. Additionally, incorporating the rules and more features into the learning-based system yields a minor improvement over the rule-based system.