Open Event Trigger Recognition Using Distant Supervision with Hierarchical Self-attentive Neural Network

Event trigger recognition plays a crucial role in open-domain event extraction. To address issues of prior work on restricted domains and constraint types of events, so as to enable robust open event trigger recognition for various domains. In this paper, we propose a novel distantly supervised framework of event trigger extraction regardless of domains. This framework consists of three components: a trigger synonym generator, a synonym set scorer and an open trigger classifier. Given the specific knowledge bases, the trigger synonym generator generates high-quality synonym sets to train the remaining components. We employ distant supervision to produce instances of event trigger, then organizes them into fine-grained synonym sets. Inspired by recent deep metric learning, we also propose a novel neural method named hierarchical self-attentive neural network (HiSNN) to score the quality of generated synonym sets. Experimental results on three datasets (including two cross-domain datasets) demonstrate the superior of our proposal compared to the state-of-the-art approaches.