GROLE: Instance-Level Group Relative Optimization for LoRA Experts in Incremental Learning

Yongyi Liao, Wencan Lai, Jun Fang, Jinjin Guo, Xiaohui Zhang, Zhiyuan Liu, Chao Liu, Pengzhang Liu, Qixia Jiang


Abstract
While Large Language Models (LLMs) demonstrate remarkable zero-shot generalization, adapting them to downstream tasks or shifting data distributions often requires continual fine-tuning—a process prone to catastrophic forgetting and limited knowledge transfer. This challenge is especially pronounced in online Incremental Learning (IL) settings, where task boundaries are blurred, and data arrives in a non-stationary stream. To address these issues, we propose GROLE (Group Relative Optimization for LoRA Experts), a novel approach that incrementally constructs a pool of frozen, task-specific Low-Rank Adaptation (LoRA) experts. At its core, GROLE employs a lightweight, instance-level expert selector optimized through a group relative reinforcement learning objective, which dynamically combines relevant experts to maximize adaptability without compromising stability. Extensive experiments across diverse incremental learning benchmarks show that GROLE consistently outperforms state-of-the-art methods, particularly in task-free and blurred-boundary settings, achieving an optimal balance between plasticity and robustness.
Anthology ID:
2026.findings-acl.1952
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
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San Diego, California, United States
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Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
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Findings
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Publisher:
Association for Computational Linguistics
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Pages:
39170–39182
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1952/
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Cite (ACL):
Yongyi Liao, Wencan Lai, Jun Fang, Jinjin Guo, Xiaohui Zhang, Zhiyuan Liu, Chao Liu, Pengzhang Liu, and Qixia Jiang. 2026. GROLE: Instance-Level Group Relative Optimization for LoRA Experts in Incremental Learning. In Findings of the Association for Computational Linguistics: ACL 2026, pages 39170–39182, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
GROLE: Instance-Level Group Relative Optimization for LoRA Experts in Incremental Learning (Liao et al., Findings 2026)
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