MetaGDPO: Alleviating Catastrophic Forgetting with Metacognitive Knowledge through Group Direct Preference Optimization
Small language models (<8B) suffer from catastrophic forgetting during knowledge distillation due to (i) misalignment between training data and the model’s intrinsic capabilities, and (ii) the absence of explicit constraints preserving previously acquired knowledge in conventional objectives. Method: We propose a dual-path solution: (1) a novel 5K-sample multitask reasoning dataset—first to incorporate metacognitive knowledge annotations—paired with a task-capability matching data selection mechanism; and (2) GDPO (Group Direct Preference Optimization), a preference-based optimization framework that leverages a reference model to implicitly guide parameter updates, jointly optimizing knowledge retention and transfer. Results: Experiments demonstrate significant mitigation of catastrophic forgetting; under resource-constrained settings, our approach approaches the performance of GRPO while substantially enhancing both reasoning capability and knowledge retention in small models.