arXiv Machine Learning

Robustness of Mixtures of Experts to Feature Noise

arXiv:2601. 14792v2 Announce Type: replace Abstract: Despite their practical success, it remains unclear why Mixture of Experts (MoE) models can outperform dense networks beyond sheer parameter scaling.

arXiv Machine Learning
Sep 4

Towards a Statistical Understanding of Mixture-of-Experts

The paper presents a statistical framework for Mixture-of-Experts (MoE) models, treating them as localized aggregation systems. It derives oracle risk bounds that separate approximation, expert‑learning, and router‑estimation errors for both dense and sparse routing with evolving experts. The authors also analyze how sparse Top‑K routing balances computational cost with performance, interpret gating geometrically, and explain how shared experts can capture common predictive structure while allowing routed experts to focus on local residuals.

By Siyuan He, Bokai Yang, Jie Hu, Ziwen Gao, Yuhong Yang
arXiv AI
Jun 2

DAG-MoE: From Simple Mixture to Structural Aggregation in Mixture-of-Experts

arXiv:2606. 01062v1 Announce Type: new Abstract: Mixture-of-Experts (MoE) models have become a leading approach for decoupling parameter count from computational cost in large language models, yet effectively scaling MoE performance remains a challenge.

By Jiarui Feng, Hanqing Zeng, Karish Grover, Ruizhong Qiu, Yinglong Xia, Qiang Zhang, Qifan Wang, Ren Chen, Dongqi Fu, Jiayi Liu, Zhoukai Zhao, Xiangjun Fan, Benyu Zhang, Yixin Chen
arXiv Machine Learning
Aug 27

Output Dilution: Redundant but Fragile Representations in MoE Models

The paper investigates how Mixture-of-Experts (MoE) models encode moral content compared to dense models. While linear probes can recover moral valence from almost all expert-layer combinations with high accuracy, these representations are far more fragile to activation noise, showing a 4.2‑fold drop in robustness. The authors attribute this fragility to output dilution: the MoE block averages across active experts, reducing the feedforward signal by nearly two orders of magnitude, which makes moral information vulnerable to perturbation even though routing remains stable.

By Orion Reblitz-Richardson