Coverage Is Not Enough: A Controlled Study of Annotation Selection for Low-Resource Sign Language

Gyanendra Shrestha, Liting Zhang


Abstract
Expert annotation is a central bottleneck in sign-language corpus construction. A natural assumption is that annotation budgets should prioritize diverse or underrepresented signing patterns. We test this in a controlled retrospective study on PHOENIX14T (German Sign Language) and Isharah (Saudi Sign Language), across gloss recognition, translation, multiple budgets, and three seeds, comparing random sampling against geometric, active-learning, pose-derived articulatory, and privileged selectors. Articulatory coverage is generally weak across all four corpus–task settings and rarely outperforms random sampling. A density analysis shows it selects locally atypical clips even after controlling for duration; removing the sparsest 10–20% helps at larger budgets but never enough to beat random. A privileged gloss-diversity oracle also performs poorly despite selecting comparatively typical clips, showing that atypicality is not the whole explanation. Facility-location representativeness is the strongest feasible selector in three of four largest-budget settings, with lower WER than random in 16 of 18 seed-matched recognition comparisons, compared with only 2 of 18 for articulatory-only selection. The results suggest pose-derived articulatory coverage and gloss-type coverage, as operationalized here, are unreliable proxies for annotation utility in low-resource sign-language corpus construction. The source code is available at https://github.com/gyan-shrestha/WSLP-2026.
Anthology ID:
2026.wslp-1.12
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:
121–131
Language:
URL:
https://aclanthology.org/2026.wslp-1.12/
DOI:
Bibkey:
Cite (ACL):
Gyanendra Shrestha and Liting Zhang. 2026. Coverage Is Not Enough: A Controlled Study of Annotation Selection for Low-Resource Sign Language. In Proceedings of the Second Workshop on Sign Language Processing, pages 121–131, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Coverage Is Not Enough: A Controlled Study of Annotation Selection for Low-Resource Sign Language (Shrestha & Zhang, WSLP 2026)
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PDF:
https://aclanthology.org/2026.wslp-1.12.pdf