Expert Calibration Lens for Pruning Mixture of Experts

Luis Frentzen Salim, Chia-Chun Wu, Tran Van Nhiem, Lun-Wei Ku, Yung-Hui Li


Abstract
Expert pruning is a practical deployment technique for Mixture-of-Experts (MoE) models. It reduces resource usage and mitigates expert redundancy, but its success depends strongly on the calibration set used for pruning. In domain-general settings, it is unclear which properties of the calibration data drive good pruning outcomes, and the effects of calibration perturbations are often unintuitive. We observe, for example, that calibration sets in different languages can lead to very similar pruning results despite appearing dissimilar on the surface.To address this, we propose Expert Calibration Lens, a lightweight analysis tool that compares expert activation patterns across datasets to predict the impact of calibration perturbations without repeatedly running expensive pruning procedures. We use activations that are quick to compute and evaluate the resulting analysis for downstream task performance.
Anthology ID:
2026.acl-demo.72
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 3: System Demonstrations)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Greg Durrett, Ping Jian
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
736–742
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-demo.72/
DOI:
Bibkey:
Cite (ACL):
Luis Frentzen Salim, Chia-Chun Wu, Tran Van Nhiem, Lun-Wei Ku, and Yung-Hui Li. 2026. Expert Calibration Lens for Pruning Mixture of Experts. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 3: System Demonstrations), pages 736–742, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Expert Calibration Lens for Pruning Mixture of Experts (Salim et al., ACL 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-acl/2026.acl-demo.72.pdf