Songjun Tu
Author directory2026
AutoSearch: Adaptive Search Depth for Efficient Agentic RAG via Reinforcement Learning
Jingbo Sun | Wenyue Chong | Songjun Tu | Qichao Zhang | Yaocheng Zhang | Jiajun Chai | Xiaohan Wang | Wei Lin | Guojun Yin | Dongbin Zhao
Findings of the Association for Computational Linguistics: ACL 2026
Jingbo Sun | Wenyue Chong | Songjun Tu | Qichao Zhang | Yaocheng Zhang | Jiajun Chai | Xiaohan Wang | Wei Lin | Guojun Yin | Dongbin Zhao
Findings of the Association for Computational Linguistics: ACL 2026
Agentic retrieval-augmented generation (RAG) systems enable large language models (LLMs) to solve complex tasks through multi-step interaction with external retrieval tools. However, such multi-step interaction often involves redundant search steps, incurring substantial computational cost and latency. Prior work limits search depth (i.e., the number of search steps) to reduce cost, but this often leads to underexploration of complex questions. To address this, we first investigate how search depth affects accuracy and find a minimal sufficient search depth that defines an accuracy-efficiency trade-off, jointly determined by question complexity and the agent’s capability. Furthermore, we propose AutoSearch, a reinforcement learning framework that evaluates each search step via self-generated intermediate answers. By a self-answering mechanism, AutoSearch identifies the minimal sufficient search depth and promotes efficient search by rewarding its attainment while penalizing over-searching. In addition, reward mechanisms are introduced to stabilize search behavior and improve answer quality on complex questions. Extensive experiments on multiple benchmarks show that AutoSearch achieves a superior accuracy-efficiency trade-off, alleviating over-searching while preserving search quality.
Dynamic Dual-Granularity Skill Bank for Agentic RL
Songjun Tu | Chengdong Xu | Qichao Zhang | Yaocheng Zhang | Xiangyuan Lan | Linjing Li | Dong Li | Dongbin Zhao
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Songjun Tu | Chengdong Xu | Qichao Zhang | Yaocheng Zhang | Xiangyuan Lan | Linjing Li | Dong Li | Dongbin Zhao
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Agentic RL can benefit substantially from reusable experience, but existing skill-based methods mostly focus on trajectory-level guidance and provide limited support for the principled evaluation and maintenance of an evolving skill memory. We propose D2Skill, a dynamic dual-granularity skill bank for agentic RL that organizes reusable experience into task skills for high-level guidance and step skills for fine-grained decision support and error correction. D2Skill jointly trains the policy and skill bank through paired baseline and skill-injected rollouts under the same policy, using their performance gap to derive hindsight utility signals for both skill updating and policy optimization. Constructed from training-time trajectories, the skill bank is continuously expanded through reflection and maintained with utility-aware retrieval and pruning. Across ALFWorld, WebShop, and Search-Augmented QA, D2Skill consistently outperforms skill-free and skill-based baselines, remains effective with self-feedback, and transfers to unseen ALFWorld environments without test-time adaptation. Project Page: https://github.com/TU2021/D2Skill-AgenticRL
PaperAudit-Bench: Benchmarking Error Detection in Research Papers for Critical Automated Peer Review
Songjun Tu | Yiwen Ma | Jiahao Lin | Qichao Zhang | Xiangyuan Lan | Junfeng. Li | Nan Xu | Linjing Li | Dongbin Zhao
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Songjun Tu | Yiwen Ma | Jiahao Lin | Qichao Zhang | Xiangyuan Lan | Junfeng. Li | Nan Xu | Linjing Li | Dongbin Zhao
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) can generate fluent peer reviews but often miss sparse, subtle, and document-level scientific errors. We introduce PaperAudit-Bench, a benchmark for evaluating paper-level error detection and error-aware automated review. It comprises two components: (1) PaperAudit-Dataset, 220 high-quality AI/ML papers containing more than 2,200 controlled synthetic errors across eight categories; and (2) PaperAudit-Review, an evidence-aware framework that links structured error detection to review generation. Experiments across models, error categories, paper sections, and analysis depths show that sparse long-context auditing remains challenging for current LLMs. Conditioning review generation on explicit, manuscript-grounded error evidence produces more conservative and discriminative assessments that align more closely with human judgments than representative automated-review baselines. The dataset also supports post-training compact detectors through SFT and RL; Qwen3-14B achieves 55.8% F1 at Detection@1 under a fixed held-out protocol. A PubPeer transfer study and deployment in ScienceOne, a scientific foundation-model platform led by the Chinese Academy of Sciences, further illustrate practical applicability.
Code and Dataset Page: https://github.com/TU2021/PaperAudit
ScienceOne Manuscript Review: https://www.scienceone.cn/lit/#/assistant
Code and Dataset Page: https://github.com/TU2021/PaperAudit
ScienceOne Manuscript Review: https://www.scienceone.cn/lit/#/assistant