arXiv AI

Mechanistic Data Attribution: Tracing the Training Origins of Interpretable LLM Units

arXiv:2601. 21996v2 Announce Type: replace-cross Abstract: While Mechanistic Interpretability has identified interpretable circuits in LLMs, their causal origins in training data remain elusive.

arXiv AI
Aug 20

Mechanistic Interpretability of Structure-Aware Numerical Reasoning in LLaMA 3.1 8B

The paper investigates how LLaMA 3.1‑8B models numerical sequence patterns, focusing on time‑series prediction. By designing a task that requires detecting structural cues—specifically first differences in a sequence—the authors show that the model performs well and internally computes and stores these differences. Probing and activation‑patching experiments reveal that LLaMA retrieves and applies the first‑difference via an induction‑like circuit, marking one of the first demonstrations of concept induction in large language models.

By Rahul Chowdhury, Timothy A Rupprecht, Senhao Cao, Jiahao Liu, Octavia Camps, David Bau, Pu Zhao, Yanzhi Wang
arXiv AI
Aug 13

Mechanist: AI as a Scientific Instrument for Discovering the Mechanisms of Intelligence

arXiv:2608. 12036v1 Announce Type: new Abstract: AI models have achieved remarkable success across diverse domains, yet the mechanisms underlying their capabilities and the risks they may pose remain poorly understood.

By Mengru Wang, Junfeng Fang, Shuofei Qiao, Zhenqian Xu, Haoming Xu, Haoxiong Wang, Shumin Deng, Linyi Yang, Zhixiang Cui, Xin Xu, Yunzhi Yao, Buqiang Xu, Fei Shen, Haozhe Luo, Yunxiang Wei, Ningyu Zhang, Julian McAuley, Tat Seng Chua, Huajun Chen
arXiv Machine Learning
Sep 23

Matryoshka attribution: Learning to attribute language model outputs to representations and weights

Matryoshka Attribution (MAttr) is a mask‑learning method that identifies nested subsets of a language model’s internal components by minimizing downstream loss. It uses a differentiable sigmoid top‑k operator and randomizes sparsity during training to produce an attribution ordering of components. MAttr tops the Mechanistic Interpretability Benchmark leaderboard and can be applied via reinforcement learning to pinpoint weight changes that control behaviors such as refusal in Llama 3.1 8B Instruct, where restoring just 1% of weights removes refusals while preserving capabilities.

By Aryaman Arora, Kirill Acharya, Nathan Hu, Yanzhe Zhang, Noah Goodman, Dan Jurafsky, Christopher Potts
arXiv AI
Aug 26

Mechanistic Circuit Identification for Controllable Data Generation

The paper introduces a circuit‑grounded framework that links training‑dynamics‑based data valuation with mechanistic interpretability. It defines data quality along learnability, challenge, and alignment, identifies internal model circuits that control these utilities, and uses them as controllable interfaces for data generation. The authors present SAMS, a stage‑aware scheduling method that steers circuit‑guided data to match the model’s evolving optimization needs, achieving more diverse and effective data than prompt‑based baselines on multiple‑choice QA tasks.

By Nakyung Lee, Sangwoo Hong, Jungwoo Lee
arXiv Machine Learning
Aug 31

How Do Linear Probes Emerge? A Circuit-Tracing Framework with Concept-Targeted Attribution

The paper introduces Concept-Targeted Attribution (CTA), a method that trains attribution graphs to explain the emergence of internal concept representations in language models, rather than just the final token prediction. CTA produces probe-specific circuits that reveal which internal computations drive a linear probe’s accuracy, and cross-layer transcoders demonstrate that these graphs contain predictive structure across multiple concept categories. Causal ablations show that probe-targeted and logit-targeted graphs capture distinct mechanisms, with probe-relevant features affecting internal concept scores and logit-relevant features altering generated tokens.

By Vedant Palit, Florent Draye, Terry Jingchen Zhang, Bernhard Sch\"olkopf, Zhijing Jin