Semi-supervised Named Entity Recognition in noisy-text

Shubhanshu Mishra, Jana Diesner


Abstract
Many of the existing Named Entity Recognition (NER) solutions are built based on news corpus data with proper syntax. These solutions might not lead to highly accurate results when being applied to noisy, user generated data, e.g., tweets, which can feature sloppy spelling, concept drift, and limited contextualization of terms and concepts due to length constraints. The models described in this paper are based on linear chain conditional random fields (CRFs), use the BIEOU encoding scheme, and leverage random feature dropout for up-sampling the training data. The considered features include word clusters and pre-trained distributed word representations, updated gazetteer features, and global context predictions. The latter feature allows for ingesting the meaning of new or rare tokens into the system via unsupervised learning and for alleviating the need to learn lexicon based features, which usually tend to be high dimensional. In this paper, we report on the solution [ST] we submitted to the WNUT 2016 NER shared task. We also present an improvement over our original submission [SI], which we built by using semi-supervised learning on labelled training data and pre-trained resourced constructed from unlabelled tweet data. Our ST solution achieved an F1 score of 1.2% higher than the baseline (35.1% F1) for the task of extracting 10 entity types. The SI resulted in an increase of 8.2% in F1 score over the base-line (7.08% over ST). Finally, the SI model’s evaluation on the test data achieved a F1 score of 47.3% (~1.15% increase over the 2nd best submitted solution). Our experimental setup and results are available as a standalone twitter NER tool at https://github.com/napsternxg/TwitterNER.
Anthology ID:
W16-3927
Volume:
Proceedings of the 2nd Workshop on Noisy User-generated Text (WNUT)
Month:
December
Year:
2016
Address:
Osaka, Japan
Venue:
WNUT
SIG:
Publisher:
The COLING 2016 Organizing Committee
Note:
Pages:
203–212
Language:
URL:
https://aclanthology.org/W16-3927
DOI:
Bibkey:
Cite (ACL):
Shubhanshu Mishra and Jana Diesner. 2016. Semi-supervised Named Entity Recognition in noisy-text. In Proceedings of the 2nd Workshop on Noisy User-generated Text (WNUT), pages 203–212, Osaka, Japan. The COLING 2016 Organizing Committee.
Cite (Informal):
Semi-supervised Named Entity Recognition in noisy-text (Mishra & Diesner, WNUT 2016)
Copy Citation:
PDF:
https://preview.aclanthology.org/nodalida-main-page/W16-3927.pdf
Code
 napsternxg/TwitterNER
Data
IPM NEL