Contrastive Learning with Prompt-derived Virtual Semantic Prototypes for Unsupervised Sentence Embedding

Jiali Zeng, Yongjing Yin, Yufan Jiang, Shuangzhi Wu, Yunbo Cao


Abstract
Contrastive learning has become a new paradigm for unsupervised sentence embeddings.Previous studies focus on instance-wise contrastive learning, attempting to construct positive pairs with textual data augmentation. In this paper, we propose a novel Contrastive learning method with Prompt-derived Virtual semantic Prototypes (ConPVP). Specifically, with the help of prompts, we construct virtual semantic prototypes to each instance, and derive negative prototypes by using the negative form of the prompts. Using a prototypical contrastive loss, we enforce the anchor sentence embedding to be close to its corresponding semantic prototypes, and far apart from the negative prototypes as well as the prototypes of other sentences. Extensive experimental results on semantic textual similarity, transfer, and clustering tasks demonstrate the effectiveness of our proposed model compared to strong baselines. Code is available at https://github.com/lemon0830/promptCSE.
Anthology ID:
2022.findings-emnlp.522
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2022
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Editors:
Yoav Goldberg, Zornitsa Kozareva, Yue Zhang
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7042–7053
Language:
URL:
https://aclanthology.org/2022.findings-emnlp.522
DOI:
10.18653/v1/2022.findings-emnlp.522
Bibkey:
Cite (ACL):
Jiali Zeng, Yongjing Yin, Yufan Jiang, Shuangzhi Wu, and Yunbo Cao. 2022. Contrastive Learning with Prompt-derived Virtual Semantic Prototypes for Unsupervised Sentence Embedding. In Findings of the Association for Computational Linguistics: EMNLP 2022, pages 7042–7053, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
Contrastive Learning with Prompt-derived Virtual Semantic Prototypes for Unsupervised Sentence Embedding (Zeng et al., Findings 2022)
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PDF:
https://aclanthology.org/2022.findings-emnlp.522.pdf