Yuanzhao Zhai
2026
EvoNarrator: Modeling Scientific Evolution for Feasible Hypothesis Generation
Xiaoying Le | Pengfei Qian | Yuanzhao Zhai | Xu Zhang | Qian Liu | Feng Dawei | Bo Ding
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Xiaoying Le | Pengfei Qian | Yuanzhao Zhai | Xu Zhang | Qian Liu | Feng Dawei | Bo Ding
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Scientific discovery evolution does not emerge in isolation but stems from the structural deepening and recombination of existing functionalities. However, current automated hypothesis generation methods, constrained by the statistical co-occurrence nature of Large Language Models (LLMs), lack perception of temporal causality and the "evolutionary patterns" inherent in scientific development. Consequently, they often yield superficial combinations that are logically infeasible. To address this, we propose EvoNarrator, a framework for hypothesis generation based on evolutionary narratives. We first extract structured P-M-L-F (Problem, Method, Limitation, Future Work) quadruples from citation networks. Subsequently, we introduce the SocketMatch mechanism, which eliminates logical disconnects between methods and problems by assessing their deep semantic compatibility. Finally, utilizing three macro patterns—Chain, Divergence, and Convergence—we constrain the generation process within historically logical derivation paths. Furthermore, double-blind expert reviews yielded an average score of 4.80/5.00 across novelty, feasibility, theoretical, and Logical. Additionally, hindcasting experiments validated its predictive foresight. Crucially, ablation studies indicate that integrating evolutionary patterns facilitates a paradigm shift from conservative incrementalism to theoretically grounded structural innovation. The code is available at https://github.com/xiyii-star/EvoNarrator.
2025
COPR: Continual Human Preference Learning via Optimal Policy Regularization
Han Zhang | Lin Gui | Yu Lei | Yuanzhao Zhai | Yehong Zhang | Zhuo Zhang | Yulan He | Hui Wang | Yue Yu | Kam-Fai Wong | Bin Liang | Ruifeng Xu
Findings of the Association for Computational Linguistics: ACL 2025
Han Zhang | Lin Gui | Yu Lei | Yuanzhao Zhai | Yehong Zhang | Zhuo Zhang | Yulan He | Hui Wang | Yue Yu | Kam-Fai Wong | Bin Liang | Ruifeng Xu
Findings of the Association for Computational Linguistics: ACL 2025
Reinforcement Learning from Human Feedback (RLHF) is effective for aligning Large Language Models (LLMs) with human preferences. However, RLHF’s complex process limits its ability to continually learn human feedback, making it impractical for real-world applications where the deployed model continuously receives feedback from users. The non-RL-based method, such as Direct Preference Optimization (DPO), is not primitively favorable for Continual Learning (CL). We observe that when combined with Experiment Relay (ER) for CL, DPO tends to significantly widen the gap in the probability of human-preferred and dispreferred responses. Consequently, this diminishes the diversity in model generation, potentially leading to model collapse. To overcome the above challenges, we propose the Continual Optimal Policy Regularization (COPR), a novel non-RL offline method to convert the historical optimal policies into optimization constraints when continually learning new preferences. We first derive a moderate reward function from the pairwise ranking loss and then use the moderate reward to calculate a new sampling distribution to construct novel learning objectives and constraints. We also provide formal proof of the learnability of COPR. The experimental results show that COPR outperforms strong CL baselines on our proposed benchmark, in terms of reward-based, GPT-4 evaluations and human assessment.