Steering LLMs? Actually, Sparse Autoencoders can outperform simple baselines

TMLR Paper9282 Authors

Abstract: Sparse Autoencoders (SAEs) have been seen as a promising avenue for exploring the internals of Large Language Models (LLMs) and for steering model output generation. When AxBench - a model steering benchmark - was introduced in Wu et al. (2025), SAEs did not seem to live up to their original hype due to poor steering performance relative to a set of simple baselines. This work serves as a partial rebuttal for Sparse Autoencoders and suggests that the results of Wu et al. (2025) did not do them full justice. We find that Sparse Autoencoders can, in fact, perform close to on par with the reference LoRA performance on the AxBench benchmark, when features are selected and labelled with our supervised pipeline. We also find that our pipeline selects features that are surprisingly causal of their identified labels when using only its interpretability-based components. Lastly, we present evidence that high sparsity (low ℓ0) may not be crucial for successful steering based on interpretability, which is in contrast to the earlier findings in Wang et al. (2025)

Submission Type: Regular submission (no more than 12 pages of main content)

Assigned Action Editor: ~Serguei_Barannikov1

Submission Number: 9282