Improving Cross-Lingual Token Representations by Adding a Pinch of SALT

Abstract:Cross-lingual sentence encoders enable scalable transfer across hundreds of languages, powering applications such as translation mining and zero-shot learning in low-resource settings. Although trained for sentence-level alignment, they are increasingly also applied to token-level tasks such as hallucination detection and sequence tagging, exposing a mismatch between training and usage. We propose SALT, a lightweight post-training method that improves token representations by injecting span-level supervision into existing sentence encoders. Across five multilingual token-level benchmarks, SALT achieves the best overall results on four of them, outperforming alternative fine-tuning strategies and competitive encoders. It also improves sentence-level performance on cross-lingual retrieval and classification tasks. These results demonstrate that span-level supervision is an effective signal for improving both token and sentence representations.

Computation and Language (cs.CL); Artificial Intelligence (cs.AI)

arXiv:2609.09953 [cs.CL]

(or arXiv:2609.09953v1 [cs.CL] for this version)

https://doi.org/10.48550/arXiv.2609.09953 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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