Xun Wang
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2026
DualAlign: Generating Clinically Grounded Synthetic Data
Rumeng Li | XWang | Hong yu
Findings of the Association for Computational Linguistics: ACL 2026
Rumeng Li | XWang | Hong yu
Findings of the Association for Computational Linguistics: ACL 2026
Synthetic clinical data are essential for advancing AI in healthcare, given strict privacy constraints on electronic health records (EHRs), the scarcity of annotated data for rare or slowly progressing conditions, and demographic biases in observational cohorts. Large language models (LLMs) can generate fluent clinical text, but ensuring that such outputs are both clinically grounded and useful for downstream modeling remains challenging. We present DualAlign, a disease-agnostic framework for generating privacy-preserving, clinically faithful synthetic EHR narratives. DualAlign improves generation fidelity through two complementary alignment mechanisms: persona alignment, which conditions generation on patient demographics and risk factors, and symptom-trajectory alignment, which grounds narratives in empirically observed longitudinal symptom patterns. Using Alzheimer’s disease (AD) as a case study, DualAlign produces context-aware, symptom-rich sentences that more closely reflect real-world clinical documentation. Augmenting limited gold-standard data with DualAlign substantially improves AD symptom classification, outperforming both gold-only training and unconstrained synthetic baselines. Overall, DualAlign provides a generalizable approach for generating high-utility synthetic clinical text in chronic and progressive diseases, reducing annotation burden while enabling scalable and privacy-conscious clinical NLP research.
2025
K-Level Reasoning: Establishing Higher Order Beliefs in Large Language Models for Strategic Reasoning
Yadong Zhang | Shaoguang Mao | Tao Ge | Xun Wang | Yan Xia | Man Lan | Furu Wei
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Yadong Zhang | Shaoguang Mao | Tao Ge | Xun Wang | Yan Xia | Man Lan | Furu Wei
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Strategic reasoning is a complex yet essential capability for intelligent agents. It requires Large Language Model (LLM) agents to adapt their strategies dynamically in multi-agent environments. Unlike static reasoning tasks, success in these contexts depends on anticipating other agents’ beliefs and actions while continuously adjusting strategies to achieve individual goals. LLMs and LLM agents often struggle with strategic reasoning due to the absence of a reasoning framework that enables them to dynamically infer others’ perspectives and adapt to changing environments. Inspired by the Level-K framework from game theory and behavioral economics, which extends reasoning from simple reactions to structured strategic depth, we propose a novel framework: “K-Level Reasoning with Large Language Models (K-R).” This framework employs recursive mechanisms to enable LLMs to achieve varying levels of strategic depth, allowing agents to form higher order beliefs—beliefs about others’ beliefs. We validate this framework through rigorous testing on four testbeds: two classical game theory problems and two social intelligence tasks. The results demonstrate the advantages of K-R in strategic reasoning. Our work presents the first recursive implementation of strategic depth in large language models (LLMs). It establishes a foundation for future research into theory of mind and strategic reasoning in LLMs.
Developing a Reliable, Fast, General-Purpose Hallucination Detection and Mitigation Service
Song Wang | Xun Wang | Jie Mei | Yujia Xie | Si-Qing Chen | Wayne Xiong
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 3: Industry Track)
Song Wang | Xun Wang | Jie Mei | Yujia Xie | Si-Qing Chen | Wayne Xiong
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 3: Industry Track)
Hallucination, a phenomenon where large language models (LLMs) produce output that is factually incorrect or unrelated to the input, is a major challenge for LLM applications that require accuracy and dependability. In this paper, we introduce a reliable and high-speed production system aimed at detecting and rectifying the hallucination issue within LLMs. Our system encompasses named entity recognition (NER), natural language inference (NLI), span-based detection (SBD), and an intricate decision tree-based process to reliably detect a wide range of hallucinations in LLM responses. Furthermore, we have crafted a rewriting mechanism that maintains an optimal mix of precision, response time, and cost-effectiveness. We detail the core elements of our framework and underscore the paramount challenges tied to response time, availability, and performance metrics, which are crucial for real-world deployment of these technologies. Our extensive evaluation, utilizing offline data and live production traffic, confirms the efficacy of our proposed framework and service.
MPO: Boosting LLM Agents with Meta Plan Optimization
Weimin Xiong | Yifan Song | Qingxiu Dong | Bingchan Zhao | Feifan Song | XWang | Sujian Li
Findings of the Association for Computational Linguistics: EMNLP 2025
Weimin Xiong | Yifan Song | Qingxiu Dong | Bingchan Zhao | Feifan Song | XWang | Sujian Li
Findings of the Association for Computational Linguistics: EMNLP 2025
Recent advancements in large language models (LLMs) have enabled LLM-based agents to successfully tackle interactive planning tasks. However, despite their successes, existing approaches often suffer from planning hallucinations and require retraining for each new agent. To address these challenges, we propose the Meta Plan Optimization (MPO) framework, , which enhances agent planning capabilities by directly incorporating explicit guidance. Unlike previous methods that rely on complex knowledge, which either require significant human effort or lack quality assurance, MPO leverages high-level general guidance through meta plans to assist agent planning and enables continuous optimization of the meta plans based on feedback from the agent’s task execution. Our experiments conducted on two representative tasks demonstrate that MPO significantly outperforms existing baselines. Moreover, our analysis indicates that MPO provides a plug-and-play solution that enhances both task completion efficiency and generalization capabilities in previous unseen scenarios.
Chain-of-Thought Matters: Improving Long-Context Language Models with Reasoning Path Supervision
Dawei Zhu | Xiyu Wei | Guangxiang Zhao | Wenhao Wu | Haosheng Zou | Junfeng Ran | XWang | Lin Sun | Xiangzheng Zhang | Sujian Li
Findings of the Association for Computational Linguistics: EMNLP 2025
Dawei Zhu | Xiyu Wei | Guangxiang Zhao | Wenhao Wu | Haosheng Zou | Junfeng Ran | XWang | Lin Sun | Xiangzheng Zhang | Sujian Li
Findings of the Association for Computational Linguistics: EMNLP 2025
Recent advances in Large Language Models (LLMs) have highlighted the challenge of handling long-context tasks, where models need to reason over extensive input contexts to aggregate target information. While Chain-of-Thought (CoT) prompting has shown promise for multi-step reasoning, its effectiveness for long-context scenarios remains underexplored. Through systematic investigation across diverse tasks, we demonstrate that CoT’s benefits generalize across most long-context scenarios and amplify with increasing context length. Motivated by this, we propose a process-supervised framework that teaches models to generate high-quality reasoning paths for enhanced long-context performance. Our framework incorporates a self-sampling mechanism to bootstrap reasoning paths and a novel quality assessment protocol specifically designed for long-context scenarios. This protocol evaluates both answer correctness and process reliability, with the latter decomposed into source faithfulness and intrinsic consistency components for efficient and accurate assessment. Experimental results on various long-context benchmarks demonstrate the effectiveness of our approach, achieving significant improvements over outcome supervision baselines on both in-domain tasks (+13.6/+3.8 points for LLaMA/Qwen on MuSiQue) and cross-domain generalization (+9.3/+8.1 points on average across diverse QA tasks). Our code, data and trained models will be released upon acceptance.
Assessing Dialect Fairness and Robustness of Large Language Models in Reasoning Tasks
Fangru Lin | Shaoguang Mao | Emanuele La Malfa | Valentin Hofmann | Adrian de Wynter | Xun Wang | Si-Qing Chen | Michael J. Wooldridge | Janet B. Pierrehumbert | Furu Wei
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Fangru Lin | Shaoguang Mao | Emanuele La Malfa | Valentin Hofmann | Adrian de Wynter | Xun Wang | Si-Qing Chen | Michael J. Wooldridge | Janet B. Pierrehumbert | Furu Wei
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Language is not monolithic. While benchmarks, including those designed for multiple languages, are often used as proxies to evaluate the performance of Large Language Models (LLMs), they tend to overlook the nuances of within-language variation and thus fail to model the experience of speakers of non-standard dialects. Focusing on African American Vernacular English (AAVE), we present the first study aimed at objectively assessing the fairness and robustness of LLMs in handling dialects across canonical reasoning tasks, including algorithm, math, logic, and integrated reasoning. We introduce ReDial (Reasoning with Dialect Queries), a benchmark containing 1.2K+ parallel query pairs in Standardized English and AAVE. We hire AAVE speakers, including experts with computer science backgrounds, to rewrite seven popular benchmarks,such as HumanEval and GSM8K. With ReDial, we evaluate widely used LLMs, including GPT, Claude, Llama, Mistral, and the Phi model families. Our findings reveal that almost all of these widely used models show significant brittleness and unfairness to queries in AAVE. Our work establishes a systematic and objective framework for analyzing LLM bias in dialectal queries. Moreover, it highlights how mainstream LLMs provide unfair service to dialect speakers in reasoning tasks, laying a critical foundation for future research.
2024
SCALE: Synergized Collaboration of Asymmetric Language Translation Engines
Xin Cheng | Xun Wang | Tao Ge | Si-Qing Chen | Furu Wei | Dongyan Zhao | Rui Yan
Findings of the Association for Computational Linguistics: ACL 2024
Xin Cheng | Xun Wang | Tao Ge | Si-Qing Chen | Furu Wei | Dongyan Zhao | Rui Yan
Findings of the Association for Computational Linguistics: ACL 2024
In this paper, we introduce SCALE, a collaborative framework that connects a compact Specialized Translation Model (STM) and a general-purpose Large Language Model (LLM) as one unified translation engine. By introducing translation from STM into the triplet in-context demonstrations, SCALE unlocks refinement and pivoting ability of LLM, thus 1) mitigating language bias of LLMs and parallel data bias of STMs, 2) enhancing LLM speciality without sacrificing generality, and 3) facilitating continual learning in a LLM-tuning-free way.Our comprehensive experiments show that SCALE significantly outperforms both LLMs (GPT-4, GPT-3.5) and supervised models (NLLB, M2M) in either high-resource or challenging low-resource settings. Moreover SCALE shows great scalability by only updating the lightweight STM and witness consistent system improvement, an averaged 4 BLEURT score across 4 languages without tuning LLM. Interestingly, SCALE could also effectively exploit the existing language bias of LLMs by using an English-centric STM as a pivot to conduct translation between any language pairs, outperforming GPT-4 by an average of 6 COMET points across eight translation directions. Furthermore we provide an in-depth analysis of SCALE’s robustness, translation characteristics, latency costs and inherent language bias, providing solid foundation for future studies exploring the potential synergy between LLMs and more specialized models.
NoteChat: A Dataset of Synthetic Patient-Physician Conversations Conditioned on Clinical Notes
Junda Wang | Zonghai Yao | Zhichao Yang | Huixue Zhou | Rumeng Li | Xun Wang | Yucheng Xu | Hong Yu
Findings of the Association for Computational Linguistics: ACL 2024
Junda Wang | Zonghai Yao | Zhichao Yang | Huixue Zhou | Rumeng Li | Xun Wang | Yucheng Xu | Hong Yu
Findings of the Association for Computational Linguistics: ACL 2024
We introduce NoteChat, a novel cooperative multi-agent framework leveraging Large Language Models (LLMs) to generate patient-physician dialogues. NoteChat embodies the principle that an ensemble of role-specific LLMs, through structured role-play and strategic prompting, can perform their assigned roles more effectively. The synergy among these role-playing LLMs results in a cohesive and efficient dialogue generation. Evaluation on MTS-dialogue, a benchmark dataset for patient-physician dialogues-note pairs, shows that models trained with the augmented synthetic patient-physician dialogues by NoteChat outperforms other state-of-the-art models for generating clinical notes. Our comprehensive automatic and human evaluation demonstrates that NoteChat substantially surpasses state-of-the-art models like ChatGPT and GPT-4 up to 22.78% by domain experts in generating superior synthetic patient-physician dialogues based on clinical notes. NoteChat has the potential to engage patients directly and help clinical documentation, a leading cause of physician burnout.
Watch Every Step! LLM Agent Learning via Iterative Step-level Process Refinement
Weimin Xiong | Yifan Song | Xiutian Zhao | Wenhao Wu | Xun Wang | Ke Wang | Cheng Li | Wei Peng | Sujian Li
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Weimin Xiong | Yifan Song | Xiutian Zhao | Wenhao Wu | Xun Wang | Ke Wang | Cheng Li | Wei Peng | Sujian Li
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Large language model agents have exhibited exceptional performance across a range of complex interactive tasks. Recent approaches have utilized tuning with expert trajectories to enhance agent performance, yet they primarily concentrate on outcome rewards, which may lead to errors or suboptimal actions due to the absence of process supervision signals. In this paper, we introduce the Iterative step-level Process Refinement (IPR) framework, which provides detailed step-by-step guidance to enhance agent training. Specifically, we adopt the Monte Carlo method to estimate step-level rewards. During each iteration, the agent explores along the expert trajectory and generates new actions. These actions are then evaluated against the corresponding step of expert trajectory using step-level rewards. Such comparison helps identify discrepancies, yielding contrastive action pairs that serve as training data for the agent. Our experiments on three complex agent tasks demonstrate that our framework outperforms a variety of strong baselines. Moreover, our analytical finds highlight the effectiveness of IPR in augmenting action efficiency and its applicability to diverse models.
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Co-authors
- Si-Qing Chen 3
- Sujian Li (李素建) 3
- Furu Wei 3
- Tao Ge 2
- Rumeng Li 2
- Shaoguang Mao 2
- Yifan Song 2
- Wenhao Wu 2
- Weimin Xiong 2
- Hong Yu 2
- Xin Cheng 1
- Qingxiu Dong 1
- Valentin Hofmann 1
- Emanuele La Malfa 1
- Man Lan 1
- Cheng Li 1
- Fangru Lin 1
- Jie Mei 1
- Wei Peng 1
- Janet Pierrehumbert 1
- Junfeng Ran 1
- Feifan Song 1
- Lin Sun 1
- Junda Wang 1
- Ke Wang 1
- Song Wang 1
- Xiyu Wei 1
- Michael J. Wooldridge 1
- Yan Xia 1
- Yujia Xie 1
- Wayne Xiong 1
- Yucheng Xu 1
- Rui Yan 1
- Zhichao Yang 1
- Zonghai Yao 1
- Xiangzheng Zhang 1
- Yadong Zhang 1
- Bingchan Zhao 1
- Dongyan Zhao 1
- Guangxiang Zhao 1
- Xiutian Zhao 1
- Huixue Zhou 1
- Dawei Zhu 1
- Haosheng Zou 1
- Adrian de Wynter 1