Guohua Liu
2026
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.
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.
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.