Sample-Size Scaling of the African Languages NLI Evaluation

Anuj Tiwari, Oluwapelumi Ogunremu, Terry Oko-odion, Jesujuwon Egbewale, Hannah Sopuruchi Nwokocha


Abstract
African languages have very little labelled data, and it is unclear if augmenting the quantity of annotation data reliably enhances downstream performance. The study is a systematic sample-size scaling study of natural language inference (NLI) on 16 African languages based on the AfriXNLI benchmark. Under controlled conditions, two multilingual transformer models with roughly 0.6B parameters XLM-R Large fine-tuned on XNLI and AfroXLM-R Large are tested on sample sizes of between 50 and 500 labeled examples and average their results across random subsampling runs. As opposed to the usual belief of monotonic increase with increased data, we find a strongly language-sensitive and often non-monotonic scaling behavior. Some languages show early saturation or decrease in performance with sample size as well as high variance in low resource regimes. These results indicate that the volume of data is not enough to guarantee stable profits to African NLI, creating the necessity of language-sensitive datasets creation and stronger multi-lingual modelling strategies.
Anthology ID:
2026.africanlp-main.22
Volume:
Proceedings of the 7th Workshop on African Natural Language Processing (AfricaNLP 2026)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Everlyn Asiko Chimoto, Constantine Lignos, Shamsuddeen Muhammad, Idris Abdulmumin, Clemencia Siro, David Ifeoluwa Adelani
Venues:
AfricaNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
217–227
Language:
URL:
https://aclanthology.org/2026.africanlp-main.22/
DOI:
Bibkey:
Cite (ACL):
Anuj Tiwari, Oluwapelumi Ogunremu, Terry Oko-odion, Jesujuwon Egbewale, and Hannah Sopuruchi Nwokocha. 2026. Sample-Size Scaling of the African Languages NLI Evaluation. In Proceedings of the 7th Workshop on African Natural Language Processing (AfricaNLP 2026), pages 217–227, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Sample-Size Scaling of the African Languages NLI Evaluation (Tiwari et al., AfricaNLP 2026)
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PDF:
https://aclanthology.org/2026.africanlp-main.22.pdf