Zhen Fang
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2026
AsyncTool: Evaluating the Asynchronous Function Calling Capability under Multi-Task Scenarios
Kou Shi | Ziao Zhang | Shiting Huang | Avery Nie | Zhen Fang | Qiuchen Wang | Lin Chen | Huaian Chen | Zehui Chen | Feng Zhao
Findings of the Association for Computational Linguistics: EMNLP 2026
Kou Shi | Ziao Zhang | Shiting Huang | Avery Nie | Zhen Fang | Qiuchen Wang | Lin Chen | Huaian Chen | Zehui Chen | Feng Zhao
Findings of the Association for Computational Linguistics: EMNLP 2026
Large language model (LLM)-based agents have demonstrated strong capabilities in leveraging external tools to solve complex tasks. However, existing evaluations largely overlook the temporal dimension of tool invocation, particularly the impact of tool response latency, and are typically limited to single-task settings. In real-world applications, multiple tasks often need to be executed concurrently, and overall efficiency critically depends on whether an agent can utilize idle time while waiting for tool responses. We refer to this capability as asynchronous tool calling. To evaluate this capability, we propose AsyncTool, a benchmark for assessing LLM-based agents in interactive multi-task tool-use environments with delayed tool feedback. AsyncTool presents multiple heterogeneous tasks simultaneously and simulates realistic tool response latency during execution. Using a hybrid data evolution strategy, we construct a diverse asynchronous multitasking dataset covering multiple scenarios and tool-use patterns. We evaluate models at three levels—step, sub-task, and task—and further introduce efficiency-oriented metrics to measure task coordination and completion efficiency. Extensive experiments show that delayed tool feedback poses substantial challenges to current agents, leading to clear performance degradation. Models that better coordinate task switching and dependency tracking tend to achieve stronger performance on AsyncTool.Our analysis identifies the main failure modes of current tool agents and provides practical guidelines for designing future systems with stronger temporal reasoning and coordination capabilities.
Internalizing Meta-Experience into Memory for Guided Reinforcement Learning in Large Language Models
Shiting Huang | Zecheng Li | Yu Zeng | Qingnan Ren | Zhen Fang | Qisheng Su | Kou Shi | Ziao Zhang | Lin Chen | Zehui Chen | Feng Zhao
Findings of the Association for Computational Linguistics: EMNLP 2026
Shiting Huang | Zecheng Li | Yu Zeng | Qingnan Ren | Zhen Fang | Qisheng Su | Kou Shi | Ziao Zhang | Lin Chen | Zehui Chen | Feng Zhao
Findings of the Association for Computational Linguistics: EMNLP 2026
Reinforcement Learning with Verifiable Rewards (RLVR) has emerged as an effective approach for enhancing the reasoning capabilities of Large Language Models (LLMs). Despite its efficacy, RLVR faces a meta-learning bottleneck: it lacks mechanisms for error attribution and experience internalization intrinsic to the human learning cycle beyond practice and verification, thereby limiting fine-grained credit assignment and reusable knowledge formation. We term such reusable knowledge representations derived from past errors as meta-experience. Based on this insight, we propose **M**eta-**E**xperience **L**earning (**MEL**), a novel framework that incorporates self-distilled meta-experience into the model’s parametric memory. Building upon standard RLVR, we introduce an additional design that leverages the LLM’s self-verification capability to conduct contrastive analysis on paired correct and incorrect trajectories, identify the precise bifurcation points where reasoning errors arise, and summarize them into generalizable meta-experience. The meta-experience is further internalized into the LLM’s parametric memory by minimizing the negative log-likelihood, which induces a language-modeled reward signal that bridges correct and incorrect reasoning trajectories and facilitates effective knowledge reuse. Experimental results demonstrate that MEL achieves consistent improvements on benchmarks, yielding 3.92%–4.73% Pass@1 gains across varying model sizes.
Video-DeepResearch: Towards the Next-Generation Multimodal Deepresearch Agent
Zhen Fang | Yu Zeng | Wenxuan Huang | Yiming Zhao | Shiting Huang | Tianfei Ren | Qi Lu | Qingnan Ren | Qisheng Su | Lionel Z. Wang | Qingyu Yin | Shuang Chen | Zehui Chen | Lin Chen | Zhenfei Yin | Yao Hu | Shaohui Lin | Wanli Ouyang | Shaosheng Cao | Feng Zhao
Findings of the Association for Computational Linguistics: EMNLP 2026
Zhen Fang | Yu Zeng | Wenxuan Huang | Yiming Zhao | Shiting Huang | Tianfei Ren | Qi Lu | Qingnan Ren | Qisheng Su | Lionel Z. Wang | Qingyu Yin | Shuang Chen | Zehui Chen | Lin Chen | Zhenfei Yin | Yao Hu | Shaohui Lin | Wanli Ouyang | Shaosheng Cao | Feng Zhao
Findings of the Association for Computational Linguistics: EMNLP 2026
We introduce Video-DeepResearch (Video-DR), extending multimodal agents from static images to continuous video streams, a setting that demands dense spatiotemporal grounding coupled with open-web exploration. Preliminary evaluations reveal two critical bottlenecks in current models: (1) modality bias, where agents bypass visual tools in favor of textual search, and (2) parametric knowledge leakage, where models rely on internal memory rather than genuine tool-augmented execution. To address these challenges, we propose Video-DeepResearch, featuring a decoupled perception-exploration pipeline with stage-wise tool unlocking that compels exhaustive cross-frame visual grounding prior to web retrieval. Our framework adopts a two-stage training recipe—supervised fine-tuning followed by Group Relative Policy Optimization (GRPO)—enabling autonomous exploration that breaks the imitation-learning ceiling. Furthermore, we curate VideoDR-Bench, a human-AI collaborative benchmark comprising 200 complex, multi-hop VQA instances. Empirical results demonstrate that our Video-DeepResearch-35B-A3B establishes a new state-of-the-art of 64.0% average accuracy, surpassing proprietary Claude-4.5-Sonnet (59.0%) by 5.0 points and significantly outperforming GPT-5 (52.5%) and Gemini 2.5 Pro (57.5%). The 30B-A3B variant achieves 59.3%, competitive with Claude-4.5-Sonnet and demonstrating the effectiveness of our training paradigm even at compact scale.
ADORA: Training Reasoning Models with Dynamic Advantage Estimation on Reinforcement Learning
Qingnan Ren | Shiting Huang | Zhen Fang | Zehui Chen | Lin Chen | Lijun Li | Feng Zhao
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Qingnan Ren | Shiting Huang | Zhen Fang | Zehui Chen | Lin Chen | Lijun Li | Feng Zhao
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Reinforcement learning has become a cornerstone technique for developing reasoning models in complex tasks, ranging from mathematical problem-solving to imaginary reasoning. The optimization of these models typically relies on policy gradient methods, whose efficacy hinges on the accurate estimation of an advantage function. However, prevailing methods typically employ static advantage estimation, a practice that leads to inefficient credit assignment by neglecting the dynamic utility of training samples over time. This limitation results in suboptimal policy updates, which in turn manifest as slower convergence rates and increased learning instability, as models fail to adapt to evolving sample utilities effectively. To address this problem, we introduce ADORA (Advantage Dynamics via Online Rollout Adaptation), a novel framework for policy optimization. ADORA dynamically adjusts the advantage function’s weighting by adaptively categorizing training data into temporarily advantageous and disadvantageous samples, based on their evolving utility during online model rollouts. This tailored data differentiation strategy allows ADORA to be seamlessly integrated into existing policy optimization algorithms without significant architectural modifications, enabling the policy to prioritize learning from more informative experiences and thereby achieve more efficient policy updates. Extensive evaluations across diverse model families and varying data scales demonstrate that ADORA is a robust and efficient framework. It significantly enhances long reasoning in both geometric and mathematical tasks, consistently achieving notable performance gains without requiring sensitive hyperparameter tuning.
UniCorn: Towards Self-Improving Unified Multimodal Models through Self-Generated Supervision
Zhen Fang | Ruiyan Han | XinYu Sun | Yuchen Ma | Ziheng Wang | Yu Zeng | Zehui Chen | Lin Chen | Wenxuan Huang | Wei-Jie Xu | Yi Cao | Feng Zhao
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Zhen Fang | Ruiyan Han | XinYu Sun | Yuchen Ma | Ziheng Wang | Yu Zeng | Zehui Chen | Lin Chen | Wenxuan Huang | Wei-Jie Xu | Yi Cao | Feng Zhao
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
While Unified Multimodal Models (UMMs) have achieved remarkable success in cross-modal comprehension, a significant gap persists in their ability to leverage such internal knowledge for high-quality generation. We formalize this discrepancy as Conduction Aphasia, a phenomenon where models accurately interpret multimodal inputs but struggle to translate that understanding into faithful and controllable synthesis. To address this, we propose UniCorn, a simple yet elegant self-improvement framework that eliminates the need for external data or teacher supervision. By partitioning a single UMM into three collaborative roles: Proposer, Solver, and Judge, UniCorn generates high-quality interactions via self-play and employs cognitive pattern reconstruction to distill latent understanding into explicit generative signals. To validate the restoration of multimodal coherence, we introduce UniCycle, a cycle-consistency benchmark based on a Text to Image to Text reconstruction loop. Extensive experiments demonstrate that UniCorn achieves comprehensive and substantial improvements over the base model across six general image generation benchmarks. Notably, it achieves SOTA performance on TIIF(73.8), DPG(86.8), CompBench(88.5), and UniCycle while further delivering substantial gains of +5.0 on WISE and +6.5 on OneIG. These results highlight that our method significantly enhances T2I generation while maintaining robust comprehension, demonstrating the scalability of fully self-supervised refinement for unified multimodal intelligence.
Beyond Accuracy: Unveiling Inefficiency Patterns in Tool-Integrated Reasoning
Qisheng Su | Shiting Huang | Zhen Fang | Ziyan Chen | Zehui Chen | Feng Zhao
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Qisheng Su | Shiting Huang | Zhen Fang | Ziyan Chen | Zehui Chen | Feng Zhao
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
In real-world Tool-Integrated Reasoning (TIR) scenarios, a major source of inefficiency is that the toolcalls create pauses between LLM requests and cause KV-cache eviction. Also, the long, unfiltered response returned by external tools inflates the KV-cache, so each decode step spends more time loading the growing cache and thus becomes steadily slower as context length increases. However, existing efficiency metrics like token counts and toolcall counts fail to capture this real computational cost. To address this, we introduce PTE (Prefill Token Equivalents), a hardware-aware TIR-efficiency metric that unifies internal reasoning and external tool-use costs while explicitly accounting for non-reusable KV-Cache and long-tool-response scenarios, thus better reflects real-world scenarios. We conduct extensive experiments across five TIR benchmarks, quantify their PTE costs, and identify four inefficiency patterns that appear in TIR. In a simulated high-concurrency industrial setting, PTE explains wall-clock latency significantly better than token-count metric. We also discover that trajectories with higher PTE costs tend to have lower reasoning correctness, indicating that simply using more tools does not improve the quality of the answer. PTE offers a new perspective on the efficiency of Tool-Integrated Reasoning. The code is available.
2025
CRITICTOOL: Evaluating Self-Critique Capabilities of Large Language Models in Tool-Calling Error Scenarios
Shiting Huang | Zhen Fang | Zehui Chen | Siyu Yuan | Junjie Ye | Yu Zeng | Lin Chen | Qi Mao | Feng Zhao
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Shiting Huang | Zhen Fang | Zehui Chen | Siyu Yuan | Junjie Ye | Yu Zeng | Lin Chen | Qi Mao | Feng Zhao
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
The ability of large language models (LLMs) to utilize external tools has enabled them to tackle an increasingly diverse range of tasks. However, as the tasks become more complex and long-horizon, the intricate tool utilization process may trigger various unexpected errors. Therefore, how to effectively handle such errors, including identifying, diagnosing, and recovering from them, has emerged as a key research direction for advancing tool learning. In this work, we first extensively analyze the types of errors encountered during the function-calling process on several competitive tool evaluation benchmarks. Based on it, we introduce CRITICTOOL, a comprehensive critique evaluation benchmark specialized for tool learning. Building upon a novel evolutionary strategy for dataset construction, CRITICTOOL holds diverse tool-use errors with varying complexities, which better reflects real-world scenarios. We conduct extensive experiments on CRITICTOOL, and validate the generalization and effectiveness of our constructed benchmark strategy. We also provide an in-depth analysis of the tool reflection ability on various LLMs, offering a new perspective on the field of tool learning in LLMs. The code is available at https://github.com/Shellorley0513/CriticTool.
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Co-authors
- Zehui Chen 7
- Feng Zhao 7
- Lin Chen 6
- Shiting Huang 6
- Yu Zeng 4
- Qingnan Ren 3
- Qisheng Su 3
- Wenxuan Huang 2
- Kou Shi 2
- Ziao Zhang 2
- Shaosheng Cao 1
- Yi Cao 1
- Huaian Chen 1
- Shuang Chen 1
- Ziyan Chen 1
- Ruiyan Han 1
- Yao Hu 1
- Lijun Li 1
- Zecheng Li 1
- Shaohui Lin 1
- Qi Lu 1
- Yuchen Ma 1
- Qi Mao 1
- Avery Nie 1
- Wanli Ouyang 1
- Tianfei Ren 1
- XinYu Sun 1
- Lionel Z. Wang 1
- Qiuchen Wang 1
- Ziheng Wang 1
- Wei-Jie Xu 1
- Junjie Ye (叶俊杰) 1
- Qingyu Yin 1
- Zhenfei Yin 1
- Siyu Yuan 1
- Yiming Zhao 1