T-Projection: High Quality Annotation Projection for Sequence Labeling Tasks

Iker García-Ferrero, Rodrigo Agerri, German Rigau


Abstract
In the absence of readily available labeled data for a given sequence labeling task and language, annotation projection has been proposed as one of the possible strategies to automatically generate annotated data. Annotation projection has often been formulated as the task of transporting, on parallel corpora, the labels pertaining to a given span in the source language into its corresponding span in the target language. In this paper we present T-Projection, a novel approach for annotation projection that leverages large pretrained text2text language models and state-of-the-art machine translation technology. T-Projection decomposes the label projection task into two subtasks: (i) A candidate generation step, in which a set of projection candidates using a multilingual T5 model is generated and, (ii) a candidate selection step, in which the generated candidates are ranked based on translation probabilities. We conducted experiments on intrinsic and extrinsic tasks in 5 Indo-European and 8 low-resource African languages. We demostrate that T-projection outperforms previous annotation projection methods by a wide margin. We believe that T-Projection can help to automatically alleviate the lack of high-quality training data for sequence labeling tasks. Code and data are publicly available.
Anthology ID:
2023.findings-emnlp.1015
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2023
Month:
December
Year:
2023
Address:
Singapore
Editors:
Houda Bouamor, Juan Pino, Kalika Bali
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
15203–15217
Language:
URL:
https://aclanthology.org/2023.findings-emnlp.1015
DOI:
10.18653/v1/2023.findings-emnlp.1015
Bibkey:
Cite (ACL):
Iker García-Ferrero, Rodrigo Agerri, and German Rigau. 2023. T-Projection: High Quality Annotation Projection for Sequence Labeling Tasks. In Findings of the Association for Computational Linguistics: EMNLP 2023, pages 15203–15217, Singapore. Association for Computational Linguistics.
Cite (Informal):
T-Projection: High Quality Annotation Projection for Sequence Labeling Tasks (García-Ferrero et al., Findings 2023)
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PDF:
https://aclanthology.org/2023.findings-emnlp.1015.pdf