Deep neural models for low-resource named entity recognition (NER) have shown
impressive results by leveraging distant super-vision or other meta-level
information (e.g. explanation). However, the costs of acquiring such additional
information are generally prohibitive, especially in domains where existing
resources (e.g. databases to be used for distant supervision) may not exist. In
this paper, we present a novel two-stage framework (AutoTriggER) to improve NER
performance by automatically generating and leveraging "entity triggers" which
are essentially human-readable clues in the text that can help guide the model
to make better decisions. Thus, the framework is able to both create and
leverage auxiliary supervision by itself. Through experiments on three
well-studied NER datasets, we show that our automatically extracted triggers
are well-matched to human triggers, and AutoTriggER improves performance over a
RoBERTa-CRFarchitecture by nearly 0.5 F1 points on average and much more in a
low resource setting.Comment: 10 pages, 12 figures, Best paper at TrustNLP@NAACL 2021 and presented
at WeaSuL@ICLR 202