Steering Large Language Models for Machine Translation Personalization

Daniel Scalena, Gabriele Sarti, Arianna Bisazza, Elisabetta Fersini, Malvina Nissim


Abstract
Large language models have simplified the production of personalized translations reflecting predefined stylistic constraints. However, these systems still struggle when stylistic requirements are implicitly represented by a set of examples, such as texts produced by a specific human translator. In this work, we explore various strategies for personalizing automatically generated translations when few examples are available, with a focus on the challenging domain of literary translation. We begin by determining the feasibility of the task and how style information is encoded within model representations. Then, we evaluate various prompting strategies and inference-time interventions for steering model generations towards a personalized style, with a particular focus on contrastive steering with sparse autoencoder (SAE) latents to identify salient personalization properties. We demonstrate that contrastive SAE steering yields robust style conditioning and translation quality, resulting in higher inference-time computational efficiency than prompting approaches. We further examine the impact of steering on model activations, finding that layers encoding personalization properties are impacted similarly by prompting and SAE steering, suggesting a similar mechanism at play.
Anthology ID:
2026.eacl-long.217
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
EACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4681–4701
Language:
URL:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-long.217/
DOI:
Bibkey:
Cite (ACL):
Daniel Scalena, Gabriele Sarti, Arianna Bisazza, Elisabetta Fersini, and Malvina Nissim. 2026. Steering Large Language Models for Machine Translation Personalization. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 4681–4701, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Steering Large Language Models for Machine Translation Personalization (Scalena et al., EACL 2026)
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https://preview.aclanthology.org/ingest-eacl/2026.eacl-long.217.pdf