Learning What Matters: End-to-End Adaptive Calibration Data Selection for LLM Pruning

Mengting Ai, Sirui Chen, Xinrui He, Maggie Zarekarizi, Kommy Weldemariam, Jingrui He


Abstract
Pruning is a critical technique for compressing Large Language Models (LLMs), yet its effectiveness is highly sensitive to the small calibration set used for parameter importance estimation. Current selection relies on simple heuristics like random sampling or entropy, causing large variation in post-pruning perplexity. In this work, we reveal the source of this instability at two levels: calibration samples are not equally important, and a distinct quality hierarchy, comprising Golden, Mediocre, and Detrimental samples, exists within any data pool. More importantly, we demonstrate that this hierarchy is not fixed: the utility of a sample is highly context-dependent, varying with the specific model and pruning algorithm, which renders static filtering approaches fundamentally insufficient. To address these, we introduce OASIS, the first end-to-end framework that directly optimizes calibration data selection with respect to the pruned model’s downstream performance. OASIS leverages a differentiable soft-mask proxy to propagate task-level gradients back to data importance weights. Comprehensive experiments across the Llama and Qwen families show that OASIS improves calibration robustness across the evaluated pruning settings, establishing a reliable standard for data-aware LLM compression.
Anthology ID:
2026.findings-emnlp.510
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
10680–10699
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.510/
DOI:
Bibkey:
Cite (ACL):
Mengting Ai, Sirui Chen, Xinrui He, Maggie Zarekarizi, Kommy Weldemariam, and Jingrui He. 2026. Learning What Matters: End-to-End Adaptive Calibration Data Selection for LLM Pruning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 10680–10699, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Learning What Matters: End-to-End Adaptive Calibration Data Selection for LLM Pruning (Ai et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.510.pdf