Multilingual Steering by Design: Multilingual Sparse Autoencoders and Principled Layer Selection
- URL: http://arxiv.org/abs/2605.23036v1
- Date: Thu, 21 May 2026 21:00:32 GMT
- Title: Multilingual Steering by Design: Multilingual Sparse Autoencoders and Principled Layer Selection
- Abstract summary: We show that training SAEs on multilingual data consistently strengthens cross-lingual representations.<n>We introduce an empha priori steering layer-selection rule based on the intersection of multilingual alignment and language separability.<n>Our results show that multilingual SAEs combined with intersection-selected layers stabilize the trade-off between language identification accuracy and generation quality.
- Score: 16.857692737043198
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: Sparse autoencoders (SAEs) enable feature-level mechanistic interpretability and activation steering in large language models (LLMs), but SAE-based language control remains unreliable in multilingual settings: most SAEs are trained on English-only data, and steering layers are chosen heuristically. We address these limitations by advancing a principled, mechanistic account of multilingual language steering with SAEs. First, we show that training SAEs on multilingual data consistently strengthens cross-lingual representations and yields more reliable, quality-preserving language control across layers and model families. Second, we introduce an \emph{a priori} steering layer-selection rule based on the intersection of multilingual alignment and language separability, which predicts effective intervention depths without exhaustive layerwise search. We evaluate our approach on LLaMA-3.1-8B and Gemma-2-9B across machine translation and cross-lingual summarization (CrossSumm), using SpBLEU, ROUGE-L, COMET, and LaSE. Our results show that multilingual SAEs combined with intersection-selected layers stabilize the trade-off between language identification accuracy and generation quality, providing a principled, predictive, representation-level account of multilingual SAE steering.
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