What Do We Talk About When We Talk About Tokenization?

Gianluca Vico, Jindřich Libovický


Abstract
Tokenization appears across a large and heterogeneous body of NLP literature, most often as a design choice rather than the primary focus. We identify more than 800 such papers published over the last decade and use an LLM-based methodology to survey them at a scale that would not be feasible through manual review. We analyze four dimensions: the languages studied, the evaluation tasks, the intrinsic metrics used, and the granularity of the tokenization units considered. We find that machine translation is the most frequently studied topic when tokenization is discussed. Despite the multilingual focus of much of this work, a strong English and Eurocentric bias persists. Subword tokenization dominates in practice despite sustained research interest in characters, bytes, and morphemes. We release the extracted dataset to support further analysis.
Anthology ID:
2026.mrl-1.26
Volume:
Proceedings of the 6th Workshop on Multilingual Representation Learning (MRL 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
David Ifeoluwa Adelani, Jesujoba Alabi, Catherine Arnett, Tyler Chang, C.M. Downey, Omer Goldman, Senyu Li, Lester James Validad Miranda, Jirui Qi, David Stap, Genta Indra Winata, Xinyu Crystina Zhang
Venues:
MRL | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
320–333
Language:
URL:
https://aclanthology.org/2026.mrl-1.26/
DOI:
Bibkey:
Cite (ACL):
Gianluca Vico and Jindřich Libovický. 2026. What Do We Talk About When We Talk About Tokenization?. In Proceedings of the 6th Workshop on Multilingual Representation Learning (MRL 2026), pages 320–333, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
What Do We Talk About When We Talk About Tokenization? (Vico & Libovický, MRL 2026)
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PDF:
https://aclanthology.org/2026.mrl-1.26.pdf