Latent-Space Intervention for Cross-Lingual Factual Consistency: Consistency Improvements without Accuracy Drops

Faeze Ghorbanpour, Constanza Fierro, Alexander Fraser, Anders Søgaard


Abstract
Large Language Models (LLMs) often answer the same factual question differently across languages. We study whether cross-lingual latent-space intervention can reduce this inconsistency. We train layer-specific autoencoders on parallel multilingual representations and apply inference-time corrections to factual QA prompts. We find that latent intervention improves geometric alignment between languages, and that this improvement translates into consistent gains in cross-lingual consistency with English across both open-ended and multiple-choice QA formats, without degrading factual accuracy. In open-ended QA, Spearman’s rank correlation between English and non-English languages improves substantially, with gains of 0.16 for English-Arabic and 0.20 for English-Russian pairs. In multiple-choice QA, answer agreement with English improves consistently across both KLAR and mParaRel. Ablations show that AE reconstruction drives these gains, whereas PCA-based and mean-shift subspace projections contribute only marginally to the observed improvements in consistency.
Anthology ID:
2026.findings-emnlp.1206
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
25464–25475
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1206/
DOI:
Bibkey:
Cite (ACL):
Faeze Ghorbanpour, Constanza Fierro, Alexander Fraser, and Anders Søgaard. 2026. Latent-Space Intervention for Cross-Lingual Factual Consistency: Consistency Improvements without Accuracy Drops. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 25464–25475, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Latent-Space Intervention for Cross-Lingual Factual Consistency: Consistency Improvements without Accuracy Drops (Ghorbanpour et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.1206.pdf