Transfer-Free Data-Efficient Multilingual Slot Labeling

Evgeniia Razumovskaia, Ivan Vulić, Anna Korhonen


Abstract
Slot labeling (SL) is a core component of task-oriented dialogue (TOD) systems, where slots and corresponding values are usually language-, task- and domain-specific. Therefore, extending the system to any new language-domain-task configuration requires (re)running an expensive and resource-intensive data annotation process. To mitigate the inherent data scarcity issue, current research on multilingual ToD assumes that sufficient English-language annotated data are always available for particular tasks and domains, and thus operates in a standard cross-lingual transfer setup. In this work, we depart from this often unrealistic assumption. We examine challenging scenarios where such transfer-enabling English annotated data cannot be guaranteed, and focus on bootstrapping multilingual data-efficient slot labelers in transfer-free scenarios directly in the target languages without any English-ready data. We propose a two-stage slot labeling approach (termed TWOSL) which transforms standard multilingual sentence encoders into effective slot labelers. In Stage 1, relying on SL-adapted contrastive learning with only a handful of SL-annotated examples, we turn sentence encoders into task-specific span encoders. In Stage 2, we recast SL from a token classification into a simpler, less data-intensive span classification task. Our results on two standard multilingual TOD datasets and across diverse languages confirm the effectiveness and robustness of TWOSL. It is especially effective for the most challenging transfer-free few-shot setups, paving the way for quick and data-efficient bootstrapping of multilingual slot labelers for TOD.
Anthology ID:
2023.emnlp-main.369
Volume:
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2023
Address:
Singapore
Editors:
Houda Bouamor, Juan Pino, Kalika Bali
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6041–6055
Language:
URL:
https://aclanthology.org/2023.emnlp-main.369
DOI:
10.18653/v1/2023.emnlp-main.369
Bibkey:
Cite (ACL):
Evgeniia Razumovskaia, Ivan Vulić, and Anna Korhonen. 2023. Transfer-Free Data-Efficient Multilingual Slot Labeling. In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing, pages 6041–6055, Singapore. Association for Computational Linguistics.
Cite (Informal):
Transfer-Free Data-Efficient Multilingual Slot Labeling (Razumovskaia et al., EMNLP 2023)
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PDF:
https://aclanthology.org/2023.emnlp-main.369.pdf