Yuewei Zhang
2026
PVPO: Pre-Estimated Value-Based Policy Optimization for Agentic Reasoning
Wenfeng Feng | Penghong Zhao | Guochao Jiang | Chuzhan Hao | Guohua Liu | Yuewei Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Wenfeng Feng | Penghong Zhao | Guochao Jiang | Chuzhan Hao | Guohua Liu | Yuewei Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Grouping-based methods have emerged as a significant frontier in Reinforcement Learning (RL), yet agentic reasoning poses a fundamental challenge for grouping-based methods: frequent environmental interactions and multi-step tool invocation generate highly variable trajectories, rendering intra-group advantage estimation unstable. In response, practitioners resort to excessive rollouts to stabilize training, which in turn incurs prohibitive computational costs. This negative feedback loop between advantage estimation instability and sampling inefficiency severely limits learning performance. We present PVPO, a stable and efficient critic-free RL framework that breaks this cycle through a pre-estimated value baseline and pre-sampled data filtering. Specifically, before training begins, PVPO performs a single round of rollouts to compute two signals: (1) Static V, a Monte Carlo estimate of the expected return that serves as a fixed baseline to stabilize advantage estimation; and (2) sample-level accuracy, as a difficulty metric to filter out trivial samples and inject ground-truth trajectories into hard ones, thereby enhancing training efficiency. As shown in Figure 1, experiments demonstrate that PVPO outperforms other grouping-based methods in both multi-step retrieval tasks and advanced mathematical reasoning benchmarks. Notably, our 7B model trained with PVPO matches or exceeds the performance of large language models (LLMs). Moreover, PVPO achieves a 2.5x speedup in training time compared to prior methods while maintaining comparable final performance.
Beyond Stochastic Exploration: What Makes Training Data Valuable for Agentic Search
Chuzhan Hao | Wenfeng Feng | Guochao Jiang | Guofeng Quan | Guohua Liu | Yuewei Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Chuzhan Hao | Wenfeng Feng | Guochao Jiang | Guofeng Quan | Guohua Liu | Yuewei Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Reinforcement learning (RL) has become an effective approach for advancing the reasoning capabilities of large language models (LLMs) through the strategic integration of external search engines. However, current RL-based search agents often rely on a process of stochastic exploration guided by carefully crafted outcome rewards, leading to inefficient reasoning trajectories and unstable training. To address these issues, we propose a novel framework, Hierarchical Experience (HiExp), to enhance the performance and training stability of search agents. Specifically, we extract empirical knowledge through contrastive analysis and a multi-level clustering mechanism, transforming raw reasoning trajectories into hierarchical experience knowledge. By leveraging experience-aligned training, we effectively regularize stochastic exploration, evolving it into a strategic and experience-driven search process. Extensive evaluations on multiple complex agentic search and mathematical reasoning benchmarks demonstrate that our approach not only achieves substantial performance gains but also exhibits strong cross-task and cross-algorithm generalization.
FAQ: Mitigating Quantization Error via Regenerating Calibration Data with Family-Aware Quantization
Haiyang Xiao | Weiqing Li | Jinyue Guo | Guochao Jiang | Guohua Liu | Yuewei Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Haiyang Xiao | Weiqing Li | Jinyue Guo | Guochao Jiang | Guohua Liu | Yuewei Zhang
Findings of the Association for Computational Linguistics: ACL 2026
Although post-training quantization (PTQ) provides an efficient numerical compression scheme for deploying large language models (LLMs) on resource-constrained devices, the representativeness and universality of calibration data remain a core bottleneck in determining the accuracy of quantization parameters. Traditional PTQ methods typically rely on limited samples, making it difficult to capture the activation distribution during the inference phase, leading to biases in quantization parameters. To address this, we propose **FAQ** (Family-Aware Quantization), a calibration data regeneration framework that leverages prior knowledge from LLMs of the same family to generate high-fidelity calibration samples. Specifically, FAQ first inputs the original calibration samples into a larger LLM from the same family as the target model, regenerating a series of high-fidelity calibration data using a highly consistent knowledge system. Subsequently, this data, carrying Chain-of-Thought reasoning and conforming to the expected activation distribution, undergoes group competition under expert guidance to select the best samples, which are then re-normalized to enhance the effectiveness of standard PTQ. Experiments on multiple model series, including Qwen3-8B, show that FAQ reduces accuracy loss by up to 28.5% compared to the baseline with original calibration data, demonstrating its powerful potential and contribution.
2025
AirRAG: Autonomous Strategic Planning and Reasoning Steer Retrieval Augmented Generation
Wenfeng Feng | Chuzhan Hao | Yuewei Zhang | Guochao Jiang | Jingyi Song
Findings of the Association for Computational Linguistics: EMNLP 2025
Wenfeng Feng | Chuzhan Hao | Yuewei Zhang | Guochao Jiang | Jingyi Song
Findings of the Association for Computational Linguistics: EMNLP 2025
Leveraging the autonomous decision-making capabilities of large language models (LLMs) has demonstrated superior performance in reasoning tasks. However, despite the success of iterative or agentic retrieval-augmented generation (RAG) techniques, these methods are often constrained to a single solution space when confronted with complex problems. In this paper, we propose a novel thinking pattern in RAG that integrates autonomous strategic planning with efficient reasoning actions, significantly activating intrinsic reasoning capabilities and expanding the solution space of specific tasks via Monte Carlo Tree Search (MCTS), which we refer to as AirRAG. Specifically, our approach designs five fundamental reasoning actions, which are expanded to a broad tree-based reasoning space using MCTS. The approach also incorporates self-consistency verification to explore potential reasoning paths and inference scaling law. Additionally, computationally optimal strategies are employed to allocate more inference resources to key actions, thereby enhancing overall performance. Experimental results demonstrate the effectiveness of AirRAG, showing significant performance gains on complex question-answering datasets. Furthermore, AirRAG is flexible and lightweight, making it easy to integrate with other advanced technologies and models.
RASD: Retrieval-Augmented Speculative Decoding
Guofeng Quan | Wenfeng Feng | Chuzhan Hao | Guochao Jiang | Yuewei Zhang | Hao Henry Wang
Findings of the Association for Computational Linguistics: ACL 2025
Guofeng Quan | Wenfeng Feng | Chuzhan Hao | Guochao Jiang | Yuewei Zhang | Hao Henry Wang
Findings of the Association for Computational Linguistics: ACL 2025
Speculative decoding accelerates inference in large language models (LLMs) by generating draft tokens for target model verification. Current approaches for obtaining draft tokens rely on lightweight draft models or additional model structures to generate draft tokens and retrieve context from databases. Due to the draft model’s small size and limited training data, model-based speculative decoding frequently becomes less effective in out-of-domain scenarios. Additionally, the time cost of the drafting phase results in a low upper limit on acceptance length during the verification step, limiting overall efficiency. This paper proposes RASD (Retrieval-Augmented Speculative Decoding), which adopts retrieval methods to enhance model-based speculative decoding. We introduce tree pruning and tree fusion to achieve this. Specifically, we develop a pruning method based on the draft model’s probability distribution to construct the optimal retrieval tree. Second, we employ the longest prefix matching algorithm to merge the tree generated by the draft model with the retrieval tree, resulting in a unified tree for verification. Experimental results demonstrate that RASD achieves state-of-the-art inference acceleration across tasks such as DocQA, Summary, Code, and In-Domain QA. Moreover, RASD exhibits strong scalability, seamlessly integrating with various speculative decoding approaches, including both generation-based and retrieval-based methods.
2024
Mixture-of-LoRAs: An Efficient Multitask Tuning Method for Large Language Models
Wenfeng Feng | Chuzhan Hao | Yuewei Zhang | Yu Han | Hao Wang
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Wenfeng Feng | Chuzhan Hao | Yuewei Zhang | Yu Han | Hao Wang
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Instruction Tuning has the potential to stimulate or enhance specific capabilities of large language models (LLMs). However, achieving the right balance of data is crucial to prevent catastrophic forgetting and interference between tasks. To address these limitations and enhance training flexibility, we propose the Mixture-of-LoRAs (MoA) architecture which is a novel and parameter-efficient tuning method designed for multi-task learning with LLMs. In this paper, we start by individually training multiple domain-specific LoRA modules using corresponding supervised corpus data. These LoRA modules can be aligned with the expert design principles observed in Mixture-of-Experts (MoE). Subsequently, we combine the multiple LoRAs using an explicit routing strategy and introduce domain labels to facilitate multi-task learning, which help prevent interference between tasks and ultimately enhances the performance of each individual task. Furthermore, each LoRA model can be iteratively adapted to a new domain, allowing for quick domain-specific adaptation. Experiments on diverse tasks demonstrate superior and robust performance, which can further promote the wide application of domain-specific LLMs.
2020
HIT-SCIR at SemEval-2020 Task 5: Training Pre-trained Language Model with Pseudo-labeling Data for Counterfactuals Detection
Xiao Ding | Dingkui Hao | Yuewei Zhang | Kuo Liao | Zhongyang Li | Bing Qin | Ting Liu
Proceedings of the Fourteenth Workshop on Semantic Evaluation
Xiao Ding | Dingkui Hao | Yuewei Zhang | Kuo Liao | Zhongyang Li | Bing Qin | Ting Liu
Proceedings of the Fourteenth Workshop on Semantic Evaluation
We describe our system for Task 5 of SemEval 2020: Modelling Causal Reasoning in Language: Detecting Counterfactuals. Despite deep learning has achieved significant success in many fields, it still hardly drives today’s AI to strong AI, as it lacks of causation, which is a fundamental concept in human thinking and reasoning. In this task, we dedicate to detecting causation, especially counterfactuals from texts. We explore multiple pre-trained models to learn basic features and then fine-tune models with counterfactual data and pseudo-labeling data. Our team HIT-SCIR wins the first place (1st) in Sub-task 1 — Detecting Counterfactual Statements and is ranked 4th in Sub-task 2 — Detecting Antecedent and Consequence. In this paper we provide a detailed description of the approach, as well as the results obtained in this task.