Target-Language Generation in Multilingual Models: Activation Steering and Optimal Control

James A. Michaelov, Carmen Amo Alonso, Tyler A. Chang, Roger P. Levy


Abstract
Ensuring that multilingual language models generate coherent text in a specific target language is a major issue in multilingual language modeling. We develop an optimal control method for target-language text generation as well as a framework for evaluating the quality of generated text in terms of language adherence, linguistic coherence, and semantic coherence. We find that the proposed method performs at least as well as the prominent difference-in-means activation steering method for the majority of models tested, with substantially less hyperparameter tuning required.
Anthology ID:
2026.emnlp-main.551
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
12644–12664
Language:
URL:
https://aclanthology.org/2026.emnlp-main.551/
DOI:
Bibkey:
Cite (ACL):
James A. Michaelov, Carmen Amo Alonso, Tyler A. Chang, and Roger P. Levy. 2026. Target-Language Generation in Multilingual Models: Activation Steering and Optimal Control. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 12644–12664, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Target-Language Generation in Multilingual Models: Activation Steering and Optimal Control (Michaelov et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.551.pdf