ECNUICA at SemEval-2021 Task 11: Rule based Information Extraction Pipeline

This paper presents our endeavor for solving task11, NLPContributionGraph, of SemEval-2021. The purpose of the task is to extract triples from a paper in the Nature Language Processing field for constructing an Open Research Knowledge Graph. The task includes three sub-tasks: detecting the contribution sentences in papers, identifying scientific terms and predicate phrases from the contribution sentences; and inferring triples in the form of (subject, predicate, object) as statements for Knowledge Graph building. In this paper, we apply an ensemble of various fine-tuned pretrained language models (PLM) for tasks one and two. In addition, the self-training methods are adopted for tackling the shortage of annotated data. For the third task, rather than using classic neural open information extraction (OIE) architectures, we generate potential triples via manually designed rules and develop a binary classifier to differentiate positive ones from others. The quantitative results show that we obtain the 4^th, 2^nd, and 2^nd rank in three evaluation phases.