Analyzing the Effect of Linguistic Similarity on Cross-Lingual Transfer: Tasks and Experimental Setups Matter

Verena Blaschke, Masha Fedzechkina, Maartje Ter Hoeve


Abstract
Cross-lingual transfer is a popular approach to increase the amount of training data for NLP tasks in a low-resource context. However, the best strategy to decide which cross-lingual data to include is unclear. Prior research often focuses on a small set of languages from a few language families and/or a single task. It is still an open question how these findings extend to a wider variety of languages and tasks. In this work, we analyze cross-lingual transfer for 263 languages from a wide variety of language families. Moreover, we include three popular NLP tasks: POS tagging, dependency parsing, and topic classification. Our findings indicate that the effect of linguistic similarity on transfer performance depends on a range of factors: the NLP task, the (mono- or multilingual) input representations, and the definition of linguistic similarity.
Anthology ID:
2025.findings-acl.454
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
8653–8684
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URL:
https://preview.aclanthology.org/display_plenaries/2025.findings-acl.454/
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Bibkey:
Cite (ACL):
Verena Blaschke, Masha Fedzechkina, and Maartje Ter Hoeve. 2025. Analyzing the Effect of Linguistic Similarity on Cross-Lingual Transfer: Tasks and Experimental Setups Matter. In Findings of the Association for Computational Linguistics: ACL 2025, pages 8653–8684, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Analyzing the Effect of Linguistic Similarity on Cross-Lingual Transfer: Tasks and Experimental Setups Matter (Blaschke et al., Findings 2025)
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https://preview.aclanthology.org/display_plenaries/2025.findings-acl.454.pdf