Bridging the gap between supervised classification and unsupervised topic modelling for social-media assisted crisis management

Mikael Brunila, Rosie Zhao, Andrei Mircea, Sam Lumley, Renee Sieber


Abstract
Social media such as Twitter provide valuable information to crisis managers and affected people during natural disasters. Machine learning can help structure and extract information from the large volume of messages shared during a crisis; however, the constantly evolving nature of crises makes effective domain adaptation essential. Supervised classification is limited by unchangeable class labels that may not be relevant to new events, and unsupervised topic modelling by insufficient prior knowledge. In this paper, we bridge the gap between the two and show that BERT embeddings finetuned on crisis-related tweet classification can effectively be used to adapt to a new crisis, discovering novel topics while preserving relevant classes from supervised training, and leveraging bidirectional self-attention to extract topic keywords. We create a dataset of tweets from a snowstorm to evaluate our method’s transferability to new crises, and find that it outperforms traditional topic models in both automatic, and human evaluations grounded in the needs of crisis managers. More broadly, our method can be used for textual domain adaptation where the latent classes are unknown but overlap with known classes from other domains.
Anthology ID:
2021.adaptnlp-1.5
Volume:
Proceedings of the Second Workshop on Domain Adaptation for NLP
Month:
April
Year:
2021
Address:
Kyiv, Ukraine
Editors:
Eyal Ben-David, Shay Cohen, Ryan McDonald, Barbara Plank, Roi Reichart, Guy Rotman, Yftah Ziser
Venue:
AdaptNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
33–49
Language:
URL:
https://aclanthology.org/2021.adaptnlp-1.5
DOI:
Bibkey:
Cite (ACL):
Mikael Brunila, Rosie Zhao, Andrei Mircea, Sam Lumley, and Renee Sieber. 2021. Bridging the gap between supervised classification and unsupervised topic modelling for social-media assisted crisis management. In Proceedings of the Second Workshop on Domain Adaptation for NLP, pages 33–49, Kyiv, Ukraine. Association for Computational Linguistics.
Cite (Informal):
Bridging the gap between supervised classification and unsupervised topic modelling for social-media assisted crisis management (Brunila et al., AdaptNLP 2021)
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PDF:
https://aclanthology.org/2021.adaptnlp-1.5.pdf