Crowdsourcing Piedmontese to Test LLMs on Non-Standard Orthography

Gianluca Vico, Jindřch Libovický


Abstract
We present a crowdsourced dataset for Piedmontese, an endangered Romance language of northwestern Italy. The dataset comprises 145 Italian–Piedmontese parallel sentences derived from Flores+, with translations produced by speakers writing in their natural orthographic style rather than adhering to standardized conventions, along with manual word alignment. We use this resource to benchmark several large language models on tokenization parity, topic classification, and machine translation. Our analysis reveals that Piedmontese incurs a tokenization penalty relative to higher-resource Romance languages, yet LLMs achieve classification performance approaching that of Italian, French, and English. Machine translation results are asymmetric: models translate adequately from Piedmontese into high-resource languages, but generation into Piedmontese remains challenging. The dataset and code are publicly released.
Anthology ID:
2026.vardial-1.6
Volume:
Proceedings of the 13th Workshop on NLP for Similar Languages, Varieties and Dialects
Month:
March
Year:
2026
Address:
Rabat, Morocco
Venues:
VarDial | WS
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Publisher:
Association for Computational Linguistics
Note:
Pages:
70–86
Language:
URL:
https://aclanthology.org/2026.vardial-1.6/
DOI:
Bibkey:
Cite (ACL):
Gianluca Vico and Jindřch Libovický. 2026. Crowdsourcing Piedmontese to Test LLMs on Non-Standard Orthography. In Proceedings of the 13th Workshop on NLP for Similar Languages, Varieties and Dialects, pages 70–86, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Crowdsourcing Piedmontese to Test LLMs on Non-Standard Orthography (Vico & Libovický, VarDial 2026)
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PDF:
https://aclanthology.org/2026.vardial-1.6.pdf