Articulator-Level Cross-Lingual Transfer in Sign Language Translation

Ali Elaswad, Omar Mokhtar Gaber Saqr


Abstract
Cross-lingual transfer is a standard approach to low-resource sign language translation, but it is unclear what the transferred model actually provides. We fine-tune a pose-based model from American Sign Language (ASL) to Indian Sign Language (ISL) and decompose the resulting transfer across its encoder, decoder, and articulator streams. The matched ASL encoder-decoder pair reaches 3.61 BLEU-4 on ISL, while either component alone performs close to training from scratch. Content-word recall reveals a sharp frequency effect: frequently observed content improves with training and additional data, whereas rare and unseen content remains near zero, even after twenty epochs and a 49% increase in training data. Finally, comparing ASL and Chinese Sign Language (CSL) sources shows that the apparent source-language gap is substantially reduced when the output language is controlled, with remaining differences concentrated differently across articulators. Because the source checkpoints also differ in pretraining domain, we treat this final pattern as suggestive rather than causal. Together, the results show that transfer provides a coupled encoder-decoder starting point, but does not by itself solve the long tail of target-language content.
Anthology ID:
2026.wslp-1.22
Volume:
Proceedings of the Second Workshop on Sign Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Sanjeet Singh, Abhinav Joshi, Pokala Dattatreya, Keren Artiaga, Khushi Jaydeep Pujara, Tomáš Železný, Ivan Gruber, Jakub Honzík, Sabyasachi Kamila, Facundo Manuel Quiroga, Marek Hrúz, Mohammed Hasanuzzaman, Ashutosh Modi
Venues:
WSLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
224–236
Language:
URL:
https://aclanthology.org/2026.wslp-1.22/
DOI:
Bibkey:
Cite (ACL):
Ali Elaswad and Omar Mokhtar Gaber Saqr. 2026. Articulator-Level Cross-Lingual Transfer in Sign Language Translation. In Proceedings of the Second Workshop on Sign Language Processing, pages 224–236, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Articulator-Level Cross-Lingual Transfer in Sign Language Translation (Elaswad & Saqr, WSLP 2026)
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PDF:
https://aclanthology.org/2026.wslp-1.22.pdf