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arXiv 2512.02004cs.LGcs.CL
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AlignSAE:概念对齐的稀疏自编码器

AlignSAE: Concept-Aligned Sparse Autoencoders

University of Arizona(亚利桑那大学);Peking University(北京大学);Shandong University(山东大学);LMU Munich(慕尼黑大学)

Minglai Yang, Xinyu Guo, Zhengliang Shi, Jinhe Bi, Steven Bethard, Mihai Surdeanu, Liangming Pan

AI总结:

AlignSAE通过预训练和后训练课程方法,实现稀疏自编码器特征与概念的对齐,提升模型对特定概念的可控性和可解释性。

摘要:

大型语言模型(LLMs)在隐藏参数空间中编码事实性知识,这些空间难以检查或控制。尽管稀疏自编码器(SAEs)可以将隐藏激活分解为更细粒度、可解释的特征,但它们通常难以可靠地将这些特征与人类定义的概念对齐,导致特征表示相互交织且分布广泛。为了解决这个问题,我们引入了AlignSAE,一种通过“预训练,然后后训练”的课程方法将SAE特征与预定义的本体对齐。在初始无监督训练阶段后,我们应用监督后训练,将特定概念绑定到专用潜在槽位,同时保留剩余容量用于一般重建。这种分离创建了一个可解释的接口,使特定概念可以被检查和控制,而不会受到无关特征的干扰。实验证明,AlignSAE能够通过针对单个、语义对齐的槽位实现精确的因果干预,例如可靠的“概念交换”,并进一步支持多跳推理和对类似“grokking”的一般化动态的机械探测。

英文摘要:

Large Language Models (LLMs) encode factual knowledge within hidden parametric spaces that are difficult to inspect or control. While Sparse Autoencoders (SAEs) can decompose hidden activations into more fine-grained, interpretable features, they often struggle to reliably align these features with human-defined concepts, resulting in entangled and distributed feature representations. To address this, we introduce AlignSAE, a method that aligns SAE features with a predefined ontology through a "pre-train, then post-train" curriculum. After an initial unsupervised training phase, we apply supervised post-training to bind specific concepts to dedicated latent slots while preserving the remaining capacity for general reconstruction. This separation creates an interpretable interface where specific concepts can be inspected and controlled without interference from unrelated features. Empirical results on GPT-2 across synthetic biographical QA (1-hop, 6 concepts) and compositional relational reasoning (2-hop, 20 concepts) demonstrate that AlignSAE enables precise causal interventions, such as reliable concept swaps (94.8% success in 1-hop), by targeting single, semantically aligned slots. AlignSAE achieves disentanglement improvements of $9$--$\infty\times$ over standard SAEs (measured via Mutual Information Gap), and further supports multi-hop reasoning and a mechanistic probe of grokking-like generalization dynamics. Although our evaluation focuses on GPT-2, AlignSAE itself is model-agnostic.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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