Document-level Event Factuality Identification via Reinforced Multi-Granularity Hierarchical Attention Networks

Document-level Event Factuality Identification via Reinforced Multi-Granularity Hierarchical Attention Networks

Zhong Qian, Peifeng Li, Qiaoming Zhu, Guodong Zhou

Proceedings of the Thirty-First International Joint Conference on Artificial Intelligence
Main Track. Pages 4338-4345. https://doi.org/10.24963/ijcai.2022/602

Document-level Event Factuality Identification (DEFI) predicts the event factuality according to the current document, and mainly depends on event-related tokens and sentences. However, previous studies relied on annotated information and did not filter irrelevant and noisy texts. Therefore, this paper proposes a novel end-to-end model, i.e., Reinforced Multi-Granularity Hierarchical Attention Network (RMHAN), which can learn information at different levels of granularity from tokens and sentences hierarchically. Moreover, with hierarchical reinforcement learning, RMHAN first selects relevant and meaningful tokens, and then selects useful sentences for document-level encoding. Experimental results on DLEF-v2 corpus show that RMHAN model outperforms several state-of-the-art baselines and achieves the best performance.
Keywords:
Natural Language Processing: Information Extraction
Natural Language Processing: Text Classification
Natural Language Processing: Information Retrieval and Text Mining
Natural Language Processing: Natural Language Semantics