Investigating Lexical Replacements for Arabic-English Code-Switched Data Augmentation

Injy Hamed, Nizar Habash, Slim Abdennadher, Ngoc Thang Vu


Abstract
Data sparsity is a main problem hindering the development of code-switching (CS) NLP systems. In this paper, we investigate data augmentation techniques for synthesizing dialectal Arabic-English CS text. We perform lexical replacements using word-aligned parallel corpora where CS points are either randomly chosen or learnt using a sequence-to-sequence model. We compare these approaches against dictionary-based replacements. We assess the quality of generated sentences through human evaluation and evaluate the effectiveness of data augmentation on machine translation (MT), automatic speech recognition (ASR), and speech translation (ST) tasks. Results show that using a predictive model results in more natural CS sentences compared to the random approach, as reported in human judgements. In the downstream tasks, despite the random approach generating more data, both approaches perform equally (outperforming dictionary-based replacements). Overall, data augmentation achieves 34% improvement in perplexity, 5.2% relative improvement on WER for ASR task, +4.0-5.1 BLEU points on MT task, and +2.1-2.2 BLEU points on ST over a baseline trained on available data without augmentation.
Anthology ID:
2023.loresmt-1.7
Volume:
Proceedings of the Sixth Workshop on Technologies for Machine Translation of Low-Resource Languages (LoResMT 2023)
Month:
May
Year:
2023
Address:
Dubrovnik, Croatia
Editors:
Atul Kr. Ojha, Chao-hong Liu, Ekaterina Vylomova, Flammie Pirinen, Jade Abbott, Jonathan Washington, Nathaniel Oco, Valentin Malykh, Varvara Logacheva, Xiaobing Zhao
Venue:
LoResMT
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
86–100
Language:
URL:
https://aclanthology.org/2023.loresmt-1.7
DOI:
10.18653/v1/2023.loresmt-1.7
Bibkey:
Cite (ACL):
Injy Hamed, Nizar Habash, Slim Abdennadher, and Ngoc Thang Vu. 2023. Investigating Lexical Replacements for Arabic-English Code-Switched Data Augmentation. In Proceedings of the Sixth Workshop on Technologies for Machine Translation of Low-Resource Languages (LoResMT 2023), pages 86–100, Dubrovnik, Croatia. Association for Computational Linguistics.
Cite (Informal):
Investigating Lexical Replacements for Arabic-English Code-Switched Data Augmentation (Hamed et al., LoResMT 2023)
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PDF:
https://aclanthology.org/2023.loresmt-1.7.pdf
Video:
 https://aclanthology.org/2023.loresmt-1.7.mp4