Relation Repository Based Adaptive Clustering for Open Relation Extraction

Clustering-based relation discovery is one of the important methods in the field of open relation extraction (OpenRE). However, samples residing in semantically overlapping regions often remain indistinguishable. In this work, we propose an adaptive clustering method based on a relation repository to explicitly model the semantic differences between clusters to mitigate the relational semantic overlap in unlabeled data. Specifically, we construct difficult samples and use bidirectional margin loss to constrain the differences of each sample and apply self-supervised contrastive learning to labeled data. Combined with contrastive learning of unlabeled data, we construct a relation repository to explicitly model the semantic differences between clusters. Meanwhile, we place greater emphasis on the difficult samples located on the boundary, enabling the model to adaptively adjust the decision boundary, which lead to generate cluster-friendly relation representations to improve the effect of open relation extraction. Experiments on two public datasets show that our method can effectively improve the performance of open relation extraction.