Haoxiang Zhang
Author directory2026
Masking Stale Observations Helps Search Agents — Until It Doesn’t: A Regime Map and Its Mechanism
Haoxiang Zhang | Qixin Xu | Zhuofeng Li | Lei Zhang | Pengcheng Jiang | Yu Zhang | Julian McAuley
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Haoxiang Zhang | Qixin Xu | Zhuofeng Li | Lei Zhang | Pengcheng Jiang | Yu Zhang | Julian McAuley
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Long-horizon search agents accumulate large amounts of retrieved content across many tool calls, making context-budget efficiency increasingly important. A minimal intervention is to mask stale observations from the context as the trajectory progresses, but it remains unclear when this form of context management helps and why. We study observation masking through a systematic sweep over various agent backbones (4B to 284B parameters) and three retrievers on offline and live-web agentic search benchmarks. We find that the accuracy gain from masking follows an asymmetric inverted-U shape when plotted against the model’s accuracy without context management: a plateau under weak retrievers, a peak in the *mismatch regime* (strong retriever × mid-capacity model), and a sharp collapse when the model is saturated. This pattern reflects the interaction between retriever recall and the model’s implicit filtering capacity, rather than either factor in isolation. Mechanistically, masking implements a token-for-turn trade-off: it removes observations the model has largely stopped attending to and pages the agent rarely re-opens. The added turns help when they convert failures into successes, but they fail when masking removes evidence the model would otherwise have used. We therefore reframe context management as a regime-dependent intervention (rather than a default choice), providing a new, holistic viewpoint that unifies the understanding of agentic deep search.
OpenResearcher: A Fully Open Pipeline for Long-Horizon Deep Research Trajectory Synthesis
Zhuofeng Li | Dongfu Jiang | Xueguang Ma | Haoxiang Zhang | Ping Nie | Yuyu Zhang | Kai Zou | Jianwen Xie | Yu Zhang | Wenhu Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Zhuofeng Li | Dongfu Jiang | Xueguang Ma | Haoxiang Zhang | Ping Nie | Yuyu Zhang | Kai Zou | Jianwen Xie | Yu Zhang | Wenhu Chen
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Training deep research agents requires long-horizon trajectories that interleave search, evidence aggregation, and multi-step reasoning. However, existing data collection pipelines typically rely on proprietary web APIs, making large-scale trajectory synthesis costly, unstable, and difficult to reproduce. We present OpenResearcher, a reproducible pipeline that decouples one-time corpus bootstrapping from multi-turn trajectory synthesis and executes the search-and-browse loop entirely offline using three explicit browser primitives: search, open, and find, over a 15M-document corpus. Using GPT-OSS-120B as the teacher model, we synthesize over 97K trajectories, including a substantial long-horizon tail with 100+ tool calls. Supervised fine-tuning a 30B-A3B backbone on these trajectories achieves 54.8% accuracy on BrowseComp-Plus, an absolute improvement of 34.0 percentage points over the base model, while remaining competitive on BrowseComp, GAIA, and xbench-DeepSearch. Because the environment is offline and fully instrumented, it also enables controlled analysis, where our study reveals practical insights into deep research pipeline design, including data filtering strategies, agent configuration choices, and how retrieval success relates to final answer accuracy.
ReviewGrounder: Improving Review Substantiveness with Rubric-Guided, Tool-Integrated Agents
Zhuofeng Li | Yi Lu | Dongfu Jiang | Haoxiang Zhang | Yuyang Bai | Chuan Li | Yu Wang | Shuiwang Ji | Jianwen Xie | Yu Zhang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Zhuofeng Li | Yi Lu | Dongfu Jiang | Haoxiang Zhang | Yuyang Bai | Chuan Li | Yu Wang | Shuiwang Ji | Jianwen Xie | Yu Zhang
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
The rapid rise in AI conference submissions has driven increasing exploration of large language models (LLMs) for peer review support. However, LLM-based reviewers often generate superficial, formulaic comments lacking substantive, evidence-grounded feedback. We attribute this to the underutilization of two key components of human reviewing: explicit rubrics and contextual grounding in existing work. To address this, we introduce ReviewBench, a benchmark evaluating review text according to paper-specific rubrics derived from official guidelines, the paper’s content, and human-written reviews. We further propose ReviewGrounder, a rubric-guided, tool-integrated multi-agent framework that decomposes reviewing into drafting and grounding stages, enriching shallow drafts via targeted evidence consolidation. Experiments on ReviewBench show that ReviewGrounder, using a Phi-4-14B-based drafter and a GPT-OSS-120B-based grounding stage, consistently outperforms baselines with substantially stronger/larger backbones (e.g., GPT-4.1 and DeepSeek-R1-670B) in both alignment with human judgments and rubric-based review quality across 8 dimensions. The code is available at https://github.com/EigenTom/ReviewGrounder.
2019
Visualizing Trends of Key Roles in News Articles
Chen Xia | Haoxiang Zhang | Jacob Moghtader | Allen Wu | Kai-Wei Chang
Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP): System Demonstrations
Chen Xia | Haoxiang Zhang | Jacob Moghtader | Allen Wu | Kai-Wei Chang
Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP): System Demonstrations
There are tons of news generated every day reflecting the change of key roles such as people, organizations and political parties. Analyzing the trend of these key roles can help understand the information flow in a more effective way. In this paper, we present a demonstration system that visualizes the news trend of key roles based on natural language processing techniques. Specifically, we apply semantic role labelling to understand relationships between key roles in the news. We also train a dynamic word embedding model to align representations of words in different time periods to measure how the similarities between a key role and news topics change over time. Note: The github link to our demo jupyter notebook and screencast video is https://github.com/kasinxc/Visualizing-Trend-of-Key-Roles-in-News-Articles