Jointly Modeling Hierarchical and Horizontal Features for Relational Triple Extraction
Recent works on relational triple extraction have shown the superiority of jointly extracting entities and relations over the pipelined extraction manner. However, most existing joint models fail to balance the modeling of entity features and the joint decoding strategy, and thus the interactions between the entity level and triple level are not fully investigated. In this work, we ﬁrst introduce the hierarchical dependency and horizontal commonality between the two levels, and then propose an entity-enhanced dual tagging framework that enables the triple extraction (TE) task to utilize such interactions with self-learned entity features through an auxiliary entity extraction (EE) task, without breaking the joint decoding of relational triples. Speciﬁcally, we align the EE and TE tasks in a position-wise manner by formulating them as two sequence labeling problems with identical encoder-decoder structure. Moreover, the two tasks are organized in a carefully designed parameter sharing setting so that the learned entity features could be naturally shared via multi-task learning. Empirical experiments on the NYT benchmark demonstrate the eﬀectiveness of the proposed framework compared to the state-of-the-art methods. extraction. It collectively exploits such interactions on top of the joint decoding strategy via multi-task leaning with a customized parameter sharing. Experimental results show that our model substantially outperforms the state-of-the-art baselines on the New York Times (NYT) benchmark.