Abstract

Distant supervised relation extraction (DSRE) is widely used to extract novel relational facts from plain text, so as to improve the knowledge graph. However, distant supervision inevitably suffers from the noisy labeling problem that will severely damage the performance of relation extraction. Currently, most DSRE methods are mainly focused on reducing the weights of noisy sentences, ignoring the bag-level noise where all sentences in a bag are wrongly labeled. In this paper, we present a novel noise detection-based relation extraction approach (NDRE) to automatically detect noisy labels with entity information and dynamically correct them, which can alleviate both instance-level and bag-level noisy problems. By this means, we can extend the dataset from the Web tables without introducing more noise. In this approach, to embed the semantics of sentences from corpus and web tables, we firstly propose a powerful sentence coder that employs an internal multi-head self-attention mechanism between the piecewise max-pooling convolutional neural network. Second, we adopt a noise detection strategy, which is expected to dynamically detect and correct the original noisy label according to the similarity between sentence representation and entity-aware embeddings. Then, we aggregate the information from corpus and web tables to make the final relation prediction. Experimental results on a public benchmark dataset demonstrate that our proposed approach achieves significant improvements over the state-of-the-art baselines and can effectively reduce the noisy labeling problem.

Highlights

  • Knowledge graphs (KGs) play a crucial role in natural language processing (NLP).KGs such as Freebase [1] and DBpedia [2] have shown their strong knowledge organization capability and are used as data resources in many NLP tasks including semantic search, intelligent question answering and text generation, among others

  • The following observations can be made: (1) Among all the baselines, our noise detection-based relation extraction approach (NDRE) achieves the best performance over the entire recall range; (2) The NDRE performs much better than piecewise convolutional neural network (PCNN)+ATT, BGWA, and PCNN+ATT+SL. It indicates that our noise-detection strategy is superior to ordinary selective attention mechanism and soft labeling based on correctly labeled instances in alleviating the noisy labeling problem

  • Forms much better than PCNN+ATT, BGWA, and PCNN+ATT+SL. It indicates that our noise-detection strategy is superior to ordinary selective attention mechanism and soft labeling based on correctly labeled instances in alleviating the noisy labeling problem. 3)

Read more

Summary

Introduction

Knowledge graphs (KGs) play a crucial role in natural language processing (NLP). KGs such as Freebase [1] and DBpedia [2] have shown their strong knowledge organization capability and are used as data resources in many NLP tasks including semantic search, intelligent question answering and text generation, among others. To alleviate the noise problem, many RE studies based on the MIL framework employ neural networks with a selective attention mechanism to assign weights to different instances within the bag [14,15,16,17,18], and all achieve good results These selective attention methods still assign a certain weight to the noisy instances (false positive instances); especially when a bag composed of single instance is wrongly labeled, as illustrated, selective attention will not work on such a bag-level noise problem. We propose a novel noise detection-based relation extraction model (NDRE), which can automatically distinguish the true positive and false positive cases in the training process by evaluating the correlation between sentences and tags, so as to alleviate the noisy labeling problem at both the instance and bag levels and avoid adding new noise labels while integrating two-hop DS data, further improving the performance of DSRE.

Related Work
Encoding Layer
Noise Detection Strategy
Bag Aggregation
Classification and Objective Function
Comparison with Baselines
Hyper-Parameter Settings
Overall Evaluation Results
Case Study
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call