Dan Zhang
Papers on this page may belong to the following people: Dan Zhang, Dan Zhang (Tsinghua University)
2026
Verification-Aware Planning for Multi-Agent Systems
Tianyang Xu | Dan Zhang | Kushan Mitra | Estevam Hruschka
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Tianyang Xu | Dan Zhang | Kushan Mitra | Estevam Hruschka
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Large language model (LLM) agents are increasingly deployed to tackle complex tasks, often necessitating collaboration among multiple specialized agents. However, multi-agent collaboration introduces new challenges in planning, coordination, and verification. Execution failures frequently arise not from flawed reasoning alone, but from subtle misalignments in task interpretation, output format, or inter-agent handoffs. To address these challenges, we present VeriMAP, a framework for multi-agent collaboration with verification-aware planning. The VeriMAP planner decomposes tasks, models subtask dependencies, and encodes planner-defined passing criteria as subtask verification functions (VFs) in Python and natural language. We evaluate VeriMAP on diverse datasets, demonstrating that it outperforms both single- and multi-agent baselines while enhancing system robustness and interpretability. Our analysis highlights how verification-aware planning enables reliable coordination and iterative refinement in multi-agent systems, without relying on external labels or annotations.
RECAP: REwriting Conversations for Intent Understanding in Agentic Planning
Kushan Mitra | Dan Zhang | Hannah Kim | Estevam Hruschka
Findings of the Association for Computational Linguistics: EACL 2026
Kushan Mitra | Dan Zhang | Hannah Kim | Estevam Hruschka
Findings of the Association for Computational Linguistics: EACL 2026
Understanding user intent is essential for effective planning in conversational assistants, particularly those powered by large language models (LLMs) coordinating multiple agents. However, real-world dialogues are often ambiguous, underspecified, or dynamic, making intent understanding a persistent challenge. Traditional classification-based approaches struggle to generalize in open-ended settings, leading to brittle interpretations and poor downstream planning.We propose RECAP (REwriting Conversations for Agent Planning), a new benchmark designed to evaluate and advance intent rewriting, reframing user-agent dialogues into concise representations of user goals. RECAP captures diverse challenges such as ambiguity, intent drift, vagueness, and mixed-goal conversations. Alongside the dataset, we introduce an LLM-based evaluator that compares planning utility given a user-agent dialogue.Using RECAP, we develop a prompt-based rewriting approach that outperforms baselines, in terms of plan preference. We further demonstrate that fine-tuning two DPO-based rewriters yields additional utility gains. Our results highlight intent rewriting as a critical and tractable component for improving agentic planning in open-domain dialogue systems.
2025
AIPOM: Agent-aware Interactive Planning for Multi-Agent Systems
Hannah Kim | Kushan Mitra | Chen Shen | Dan Zhang | Estevam Hruschka
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing: System Demonstrations
Hannah Kim | Kushan Mitra | Chen Shen | Dan Zhang | Estevam Hruschka
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing: System Demonstrations
Large language models (LLMs) are being increasingly used for planning in orchestrated multi-agent systems. However, existing LLM-based approaches often fall short of human expectations and, critically, lack effective mechanisms for users to inspect, understand, and control their behaviors. These limitations call for enhanced transparency, controllability, and human oversight. To address this, we introduce AIPOM, a system supporting human-in-the-loop planning through conversational and graph-based interfaces. AIPOM enables users to transparently inspect, refine, and collaboratively guide LLM-generated plans, significantly enhancing user control and trust in multi-agent workflows. Our code and demo video are available at https://github.com/megagonlabs/aipom.
FactLens: Benchmarking Fine-Grained Fact Verification
Kushan Mitra | Dan Zhang | Sajjadur Rahman | Estevam Hruschka
Findings of the Association for Computational Linguistics: ACL 2025
Kushan Mitra | Dan Zhang | Sajjadur Rahman | Estevam Hruschka
Findings of the Association for Computational Linguistics: ACL 2025
Large Language Models (LLMs) have shown impressive capability in language generation and understanding, but their tendency to hallucinate and produce factually incorrect information remains a key limitation. To verify LLM-generated contents and claims from other sources, traditional verification approaches often rely on holistic models that assign a single factuality label to complex claims, potentially obscuring nuanced errors. In this paper, we advocate for a shift towards fine-grained verification, where complex claims are broken down into smaller sub-claims for individual verification, allowing for more precise identification of inaccuracies, improved transparency, and reduced ambiguity in evidence retrieval. However, generating sub-claims poses challenges, such as maintaining context and ensuring semantic equivalence with respect to the original claim. We introduce **FactLens**, a benchmark for evaluating fine-grained fact verification, with metrics and automated evaluators of sub-claim quality. The benchmark data is manually curated to ensure high-quality ground truth. Our results show alignment between automated FactLens evaluators and human judgments, and we discuss the impact of sub-claim characteristics on the overall verification performance.
How LLMs React to Industrial Spatio-Temporal Data? Assessing Hallucination with a Novel Traffic Incident Benchmark Dataset
Qiang Li | Mingkun Tan | Xun Zhao | Dan Zhang | Daoan Zhang | Shengzhao Lei | Anderson S. Chu | Lujun Li | Porawit Kamnoedboon
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)
Qiang Li | Mingkun Tan | Xun Zhao | Dan Zhang | Daoan Zhang | Shengzhao Lei | Anderson S. Chu | Lujun Li | Porawit Kamnoedboon
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)
Large language models (LLMs) hold revolutionary potential to digitize and enhance the Health & Public Services (H&PS) industry. Despite their advanced linguistic abilities, concerns about accuracy, stability, and traceability still persist, especially in high-stakes areas such as transportation systems. Moreover, the predominance of English in LLM development raises questions about how they perform in non-English contexts. This study originated from a real world industrial GenAI application, introduces a novel cross-lingual benchmark dataset comprising nearly 99,869 real traffic incident records from Vienna (2013-2023) to assess the robustness of state-of-the-art LLMs (≥ 9) in the spatio vs temporal domain for traffic incident classification. We then explored three hypotheses — sentence indexing, date-to-text conversion, and German-to-English translation — and incorporated Retrieval Augmented Generation (RAG) to further examine the LLM hallucinations in both spatial and temporal domain. Our experiments reveal significant performance disparities in the spatio-temporal domain and demonstrate what types of hallucinations that RAG can mitigate and how it achieves this. We also provide open access to our H&PS traffic incident dataset, with the project demo and code available at Website https://sites.google.com/view/llmhallucination/home
2024
Prompting GPT-4 for Chinese Essay Fluency Evaluation
Dan Zhang | Thuong Hoang | Ye Zhu
Proceedings of the 23rd Chinese National Conference on Computational Linguistics (Volume 3: Evaluations)
Dan Zhang | Thuong Hoang | Ye Zhu
Proceedings of the 23rd Chinese National Conference on Computational Linguistics (Volume 3: Evaluations)
“This report presents the methodology and results of utilizing GPT-4 for CCL24-Eval Task 7 of Chinese Essay Fluency Evaluation (CEFE). The task is divided into three tracks: Identification of Error Sentence Types, Rewriting Error Sentences, and Essay Fluency Rating. We employed a few-shot prompt engineering to guide GPT-4 in performing this task. Our approach integrated fine-grained error analysis with advanced NLP techniques to provide detailed, actionable feedback for students and teachers. Despite some successes, particularly in generating semantically similar and syntactically relevant corrections, our analysis revealed significant challenges, especially in multiple-label classification and the accurate identification of error types. The report discusses these findings and suggests areas for further improvement.”
MEGAnno+: A Human-LLM Collaborative Annotation System
Hannah Kim | Kushan Mitra | Rafael Li Chen | Sajjadur Rahman | Dan Zhang
Proceedings of the 18th Conference of the European Chapter of the Association for Computational Linguistics: System Demonstrations
Hannah Kim | Kushan Mitra | Rafael Li Chen | Sajjadur Rahman | Dan Zhang
Proceedings of the 18th Conference of the European Chapter of the Association for Computational Linguistics: System Demonstrations
Large language models (LLMs) can label data faster and cheaper than humans for various NLP tasks. Despite their prowess, LLMs may fall short in understanding of complex, sociocultural, or domain-specific context, potentially leading to incorrect annotations. Therefore, we advocate a collaborative approach where humans and LLMs work together to produce reliable and high-quality labels. We present MEGAnno+, a human-LLM collaborative annotation system that offers effective LLM agent and annotation management, convenient and robust LLM annotation, and exploratory verification of LLM labels by humans.
2023
DeakinNLP at ProbSum 2023: Clinical Progress Note Summarization with Rules and Language ModelsClinical Progress Note Summarization with Rules and Languague Models
Ming Liu | Dan Zhang | Weicong Tan | He Zhang
Proceedings of the 22nd Workshop on Biomedical Natural Language Processing and BioNLP Shared Tasks
Ming Liu | Dan Zhang | Weicong Tan | He Zhang
Proceedings of the 22nd Workshop on Biomedical Natural Language Processing and BioNLP Shared Tasks
This paper summarizes two approaches developed for BioNLP2023 workshop task 1A: clinical problem list summarization. We develop two types of methods with either rules or pre-trained language models. In the rule-based summarization model, we leverage UMLS (Unified Medical Language System) and a negation detector to extract text spans to represent the summary. We also fine tune three pre-trained language models (BART, T5 and GPT2) to generate the summaries. Experiment results show the rule based system returns extractive summaries but lower ROUGE-L score (0.043), while the fine tuned T5 returns a higher ROUGE-L score (0.208).
2022
MEGAnno: Exploratory Labeling for NLP in Computational Notebooks
Dan Zhang | Hannah Kim | Rafael Li Chen | Eser Kandogan | Estevam Hruschka
Proceedings of the Fourth Workshop on Data Science with Human-in-the-Loop (Language Advances)
Dan Zhang | Hannah Kim | Rafael Li Chen | Eser Kandogan | Estevam Hruschka
Proceedings of the Fourth Workshop on Data Science with Human-in-the-Loop (Language Advances)
We present MEGAnno, a novel exploratory annotation framework designed for NLP researchers and practitioners. Unlike existing labeling tools that focus on data labeling only, our framework aims to support a broader, iterative ML workflow including data exploration and model development. With MEGAnno’s API, users can programmatically explore the data through sophisticated search and automated suggestion functions and incrementally update task schema as their project evolve. Combined with our widget, the users can interactively sort, filter, and assign labels to multiple items simultaneously in the same notebook where the rest of the NLP project resides. We demonstrate MEGAnno’s flexible, exploratory, efficient, and seamless labeling experience through a sentiment analysis use case.
Multi-level Distillation of Semantic Knowledge for Pre-training Multilingual Language Model
Mingqi Li | Fei Ding | Dan Zhang | Long Cheng | Hongxin Hu | Feng Luo
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Mingqi Li | Fei Ding | Dan Zhang | Long Cheng | Hongxin Hu | Feng Luo
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Pre-trained multilingual language models play an important role in cross-lingual natural language understanding tasks. However, existing methods did not focus on learning the semantic structure of representation, and thus could not optimize their performance. In this paper, we propose Multi-level Multilingual Knowledge Distillation (MMKD), a novel method for improving multilingual language models. Specifically, we employ a teacher-student framework to adopt rich semantic representation knowledge in English BERT. We propose token-, word-, sentence-, and structure-level alignment objectives to encourage multiple levels of consistency between source-target pairs and correlation similarity between teacher and student models. We conduct experiments on cross-lingual evaluation benchmarks including XNLI, PAWS-X, and XQuAD. Experimental results show that MMKD outperforms other baseline models of similar size on XNLI and XQuAD and obtains comparable performance on PAWS-X. Especially, MMKD obtains significant performance gains on low-resource languages.
Low-resource Interactive Active Labeling for Fine-tuning Language Models
Seiji Maekawa | Dan Zhang | Hannah Kim | Sajjadur Rahman | Estevam Hruschka
Findings of the Association for Computational Linguistics: EMNLP 2022
Seiji Maekawa | Dan Zhang | Hannah Kim | Sajjadur Rahman | Estevam Hruschka
Findings of the Association for Computational Linguistics: EMNLP 2022
Recently, active learning (AL) methods have been used to effectively fine-tune pre-trained language models for various NLP tasks such as sentiment analysis and document classification. However, given the task of fine-tuning language models, understanding the impact of different aspects on AL methods such as labeling cost, sample acquisition latency, and the diversity of the datasets necessitates a deeper investigation. This paper examines the performance of existing AL methods within a low-resource, interactive labeling setting. We observe that existing methods often underperform in such a setting while exhibiting higher latency and a lack of generalizability. To overcome these challenges, we propose a novel active learning method TYROUGE that employs a hybrid sampling strategy to minimize labeling cost and acquisition latency while providing a framework for adapting to dataset diversity via user guidance. Through our experiments, we observe that compared to SOTA methods, TYROUGE reduces the labeling cost by up to 43% and the acquisition latency by as much as 11X, while achieving comparable accuracy. Finally, we discuss the strengths and weaknesses of TYROUGE by exploring the impact of dataset characteristics.