tailieunhanh - Báo cáo khoa học: "A Cross-Lingual ILP Solution to Zero Anaphora Resolution"

We present an ILP-based model of zero anaphora detection and resolution that builds on the joint determination of anaphoricity and coreference model proposed by Denis and Baldridge (2007), but revises it and extends it into a three-way ILP problem also incorporating subject detection. We show that this new model outperforms several baselines and competing models, as well as a direct translation of the Denis / Baldridge model, for both Italian and Japanese zero anaphora. | A Cross-Lingual ILP Solution to Zero Anaphora Resolution Ryu Iida Tokyo Institute of Technology 2-12-1 Ookayama Meguro Tokyo 152-8552 Japan ryu-i@ Massimo Poesio Universita di Trento Center for Mind Brain Sciences University of Essex Language and Computation Group Abstract We present an ILP-based model of zero anaphora detection and resolution that builds on the joint determination of anaphoricity and coreference model proposed by Denis and Baldridge 2007 but revises it and extends it into a three-way ILP problem also incorporating subject detection. We show that this new model outperforms several baselines and competing models as well as a direct translation of the Denis Baldridge model for both Italian and Japanese zero anaphora. We incorporate our model in complete anaphoric resolvers for both Italian and Japanese showing that our approach leads to improved performance also when not used in isolation provided that separate classifiers are used for zeros and for explicitly realized anaphors. 1 Introduction In so-called pro-drop languages such as Japanese and many romance languages including Italian phonetic realization is not required for anaphoric references in contexts in which in English noncontrastive pronouns are used . the subjects of Italian and Japanese translations of buy in 1b and 1c are not explicitly realized. We call these nonrealized mandatory arguments zero anaphors. 1 a. EN John j went to visit some friends. On the way he j bought some wine. b. IT Giovannif ando a far visita a degli amici. Per via ội compro del vino. c. JA John j-wa yujin-o houmon-sita. Tochu-de ội wain-o ka-tta. 804 The felicitousness of zero anaphoric reference depends on the referred entity being sufficiently salient hence this type of data-particularly in Japanese and Italian-played a key role in early work in coreference resolution . in the development of Centering Kameyama 1985 Walker et al. 1994 Di Eugenio 1998 . This research