Extrapolating Multilingual Understanding Models as Multilingual Generators

Bohong Wu, Fei Yuan, Hai Zhao, Lei Li, Jingjing Xu


Abstract
Multilingual understanding models (or encoder-based), pre-trained via masked language modeling, have achieved promising results on many language understanding tasks (e.g., mBERT). However, these models are not capable of generating high-quality text compared with decoder-based causal language models. Can we transform a pre-trained language understanding model into an effective language generation model? We propose a Semantic-Guided Alignment-then-Denoising (SGA) approach to adapt a multilingual encoder to a multilingual generator with a small number of additional parameters. Experiments show that the proposed approach is an effective adaption method, outperforming widely-used initialization-based methods with gains of 9.4 BLEU on machine translation, 8.1 Rouge-L on question generation, and 5.5 METEOR on story generation on XLM-Rlarge. On the other hand, we observe that XLM-R is still inferior to mBART in supervised settings despite better results on zero-shot settings, indicating that more exploration is required to make understanding models strong generators. Our code is available at https://github.com/chengzhipanpan/XLMR4MT.
Anthology ID:
2023.findings-emnlp.1031
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:
15432–15444
Language:
URL:
https://aclanthology.org/2023.findings-emnlp.1031
DOI:
10.18653/v1/2023.findings-emnlp.1031
Bibkey:
Cite (ACL):
Bohong Wu, Fei Yuan, Hai Zhao, Lei Li, and Jingjing Xu. 2023. Extrapolating Multilingual Understanding Models as Multilingual Generators. In Findings of the Association for Computational Linguistics: EMNLP 2023, pages 15432–15444, Singapore. Association for Computational Linguistics.
Cite (Informal):
Extrapolating Multilingual Understanding Models as Multilingual Generators (Wu et al., Findings 2023)
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PDF:
https://preview.aclanthology.org/add_acl24_videos/2023.findings-emnlp.1031.pdf