论文标题
联合实体关系提取的两相范式
A Two-Phase Paradigm for Joint Entity-Relation Extraction
论文作者
论文摘要
已经进行了一项详尽的研究，以研究基于跨度的联合实体和关系提取任务的模型。但是，这些模型在模型训练过程中采样了大量的负实体和负关系，这是必不可少的，但导致数据分布严重不平衡，进而导致次优模型性能。为了解决上述问题，我们为基于跨度的联合实体和关系提取提出了两阶段范式，其中涉及在第一阶段对实体和关系进行分类，并预测第二阶段这些实体和关系的类型。两阶段范式使我们的模型能够显着缩小数据分布差距，包括负实体与其他实体之间的差距，以及负面关系与其他关系之间的差距。此外，我们首次尝试将实体类型和实体距离与全球特征相结合，这已被证明有效，尤其是对于关系提取而言。几个数据集的实验结果表明，基于两相范式的基于跨度的关节提取模型增强，全局特征始终优于以前的联合提取任务基于最新的跨度模型，建立了新的标准基准。定性和定量分析进一步验证了提出的范式和全球特征的有效性。
An exhaustive study has been conducted to investigate span-based models for the joint entity and relation extraction task. However, these models sample a large number of negative entities and negative relations during the model training, which are essential but result in grossly imbalanced data distributions and in turn cause suboptimal model performance. In order to address the above issues, we propose a two-phase paradigm for the span-based joint entity and relation extraction, which involves classifying the entities and relations in the first phase, and predicting the types of these entities and relations in the second phase. The two-phase paradigm enables our model to significantly reduce the data distribution gap, including the gap between negative entities and other entities, as well as the gap between negative relations and other relations. In addition, we make the first attempt at combining entity type and entity distance as global features, which has proven effective, especially for the relation extraction. Experimental results on several datasets demonstrate that the spanbased joint extraction model augmented with the two-phase paradigm and the global features consistently outperforms previous state-of-the-art span-based models for the joint extraction task, establishing a new standard benchmark. Qualitative and quantitative analyses further validate the effectiveness the proposed paradigm and the global features.
