Stephen Wang
Author directoryAlso published as: Zhiguang Wang
2026
SagE-QG: Skill-Aligned and Evidence-Grounded Educational Question Generation via Counterfactual Evidence Reinforcement Learning
Yuqiu Deng | Chaoli Zhang | Chenyu Liu | Xingjun Wei | Xinliang Zhou | Zhiguang Wang | Yanfeng Wang | Haoyang Li | Qingsong Wen
Findings of the Association for Computational Linguistics: EMNLP 2026
Yuqiu Deng | Chaoli Zhang | Chenyu Liu | Xingjun Wei | Xinliang Zhou | Zhiguang Wang | Yanfeng Wang | Haoyang Li | Qingsong Wen
Findings of the Association for Computational Linguistics: EMNLP 2026
Automatic Question Generation (QG) can make reading-comprehension practice and assessment scalable. For educational use, generated questions should diagnose a target comprehension skill and rely on the passage evidence an expert would use to write the question. Existing answer-aware and skill-conditioned QG methods improve controllability, but often leave these skill-to-question and evidence-to-question dependencies implicit. We present SagE-QG, a Skill-aligned and Evidence-Grounding Framework for Question Generation. SagE-QG exposes evidence-grounded trajectories, optimizes multi-aspect rewards for answerability, skill alignment, and human similarity, and applies Counterfactual Evidence Intervention in reinforcement learning. The intervention removes selected evidence and rewards the Interventional Grounding Gap between full-passage and masked-evidence generations. Experiments on three reading-comprehension QG datasets show that SagE-QG delivers stronger educational quality, especially in skill alignment and answerability, while achieving competitive reference-based results.
Time-RA: Towards Time Series Reasoning for Anomaly Diagnosis with LLM Feedback
Yiyuan Yang | Zichuan Liu | Lei Song | Kai Ying | Stephen Wang | Joshua Thomas Bamford | Svitlana Vyetrenko | Jiang Bian | Qingsong Wen
Findings of the Association for Computational Linguistics: ACL 2026
Yiyuan Yang | Zichuan Liu | Lei Song | Kai Ying | Stephen Wang | Joshua Thomas Bamford | Svitlana Vyetrenko | Jiang Bian | Qingsong Wen
Findings of the Association for Computational Linguistics: ACL 2026
Time series anomaly detection (TSAD) has traditionally focused on binary classification and often lacks the fine-grained categorization and explanatory reasoning required for transparent decision-making. To address these limitations, we propose Time-series Reasoning for Anomaly (Time-RA), a novel task that reformulates TSAD from a discriminative into a generative, reasoning-intensive paradigm. To facilitate this, we introduce RATs40K, the first real-world large-scale multimodal benchmark with ~40,000 samples across 10 domains, integrating raw time series, textual context, and visual plots with structured reasoning annotations. Extensive benchmarking shows that while supervised fine-tuning and visual representations boost diagnostic accuracy and reasoning consistency, performance varies across complex scenarios. Notably, fine-tuned models demonstrate strong “plug-and-play” transferability, outperforming traditional baselines on unseen real-world datasets. Our work establishes a foundation for interpretable, multimodal time series analysis. All code and the RATs40K dataset are fully open-sourced to facilitate future research.
Hybrid Self-evolving Structured Memory for Computer-Use Agents
Sibo Zhu | Wenyi WU | Kun Zhou | Stephen Wang | Biwei Huang
Findings of the Association for Computational Linguistics: ACL 2026
Sibo Zhu | Wenyi WU | Kun Zhou | Stephen Wang | Biwei Huang
Findings of the Association for Computational Linguistics: ACL 2026
The remarkable progress of vision–language models (VLMs) has enabled computer-use agents to interact with computers in a human-like manner. Yet real-world computer-use tasks remain difficult due to long-horizon workflows, diverse interfaces, and frequent intermediate errors. Prior work equips agents with external memory built from large collections of trajectories, but relies on flat retrieval over discrete summaries or continuous embeddings, falling short of the structured organization and self-evolving characteristics of human memory. Inspired by the brain, we propose Hybrid Self-evolving Structured Memory (HyMEM), a graph-based memory that couples discrete high-level symbolic nodes with continuous trajectory embeddings. HyMEM maintains a graph structure to support multi-hop retrieval, self-evolution via node update operations, and on-the-fly working-memory refreshing during inference. Extensive experiments show that HyMEM consistently improves open-source computer-use agents, enabling 7B/8B backbones to match or surpass strong closed-source models; notably, it boosts Qwen2.5-VL-7B by +22.5% and outperforms Gemini2.5-Pro-Vision and GPT-4o.
2021
Leveraging Slot Descriptions for Zero-Shot Cross-Domain Dialogue StateTracking
Zhaojiang Lin | Bing Liu | Seungwhan Moon | Paul Crook | Zhenpeng Zhou | Zhiguang Wang | Zhou Yu | Andrea Madotto | Eunjoon Cho | Rajen Subba
Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies
Zhaojiang Lin | Bing Liu | Seungwhan Moon | Paul Crook | Zhenpeng Zhou | Zhiguang Wang | Zhou Yu | Andrea Madotto | Eunjoon Cho | Rajen Subba
Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies
Zero-shot cross-domain dialogue state tracking (DST) enables us to handle unseen domains without the expense of collecting in-domain data. In this paper, we propose a slot descriptions enhanced generative approach for zero-shot cross-domain DST. Specifically, our model first encodes a dialogue context and a slot with a pre-trained self-attentive encoder, and generates slot value in auto-regressive manner. In addition, we incorporate Slot Type Informed Descriptions that capture the shared information of different slots to facilitates the cross-domain knowledge transfer. Experimental results on MultiWOZ shows that our model significantly improve existing state-of-the-art results in zero-shot cross-domain setting.
Adding Chit-Chat to Enhance Task-Oriented Dialogues
Kai Sun | Seungwhan Moon | Paul Crook | Stephen Roller | Becka Silvert | Bing Liu | Zhiguang Wang | Honglei Liu | Eunjoon Cho | Claire Cardie
Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies
Kai Sun | Seungwhan Moon | Paul Crook | Stephen Roller | Becka Silvert | Bing Liu | Zhiguang Wang | Honglei Liu | Eunjoon Cho | Claire Cardie
Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies
Existing dialogue corpora and models are typically designed under two disjoint motives: while task-oriented systems focus on achieving functional goals (e.g., booking hotels), open-domain chatbots aim at making socially engaging conversations. In this work, we propose to integrate both types of systems by Adding Chit-Chat to ENhance Task-ORiented dialogues (ACCENTOR), with the goal of making virtual assistant conversations more engaging and interactive. Specifically, we propose a Human <-> AI collaborative data collection approach for generating diverse chit-chat responses to augment task-oriented dialogues with minimal annotation effort. We then present our new chit-chat-based annotations to 23.8K dialogues from two popular task-oriented datasets (Schema-Guided Dialogue and MultiWOZ 2.1) and demonstrate their advantage over the originals via human evaluation. Lastly, we propose three new models for adding chit-chat to task-oriented dialogues, explicitly trained to predict user goals and to generate contextually relevant chit-chat responses. Automatic and human evaluations show that, compared with the state-of-the-art task-oriented baseline, our models can code-switch between task and chit-chat to be more engaging, interesting, knowledgeable, and humanlike, while maintaining competitive task performance.
Zero-Shot Dialogue State Tracking via Cross-Task Transfer
Zhaojiang Lin | Bing Liu | Andrea Madotto | Seungwhan Moon | Zhenpeng Zhou | Paul Crook | Zhiguang Wang | Zhou Yu | Eunjoon Cho | Rajen Subba | Pascale Fung
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Zhaojiang Lin | Bing Liu | Andrea Madotto | Seungwhan Moon | Zhenpeng Zhou | Paul Crook | Zhiguang Wang | Zhou Yu | Eunjoon Cho | Rajen Subba | Pascale Fung
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Zero-shot transfer learning for dialogue state tracking (DST) enables us to handle a variety of task-oriented dialogue domains without the expense of collecting in-domain data. In this work, we propose to transfer the cross-task knowledge from general question answering (QA) corpora for the zero-shot DST task. Specifically, we propose TransferQA, a transferable generative QA model that seamlessly combines extractive QA and multi-choice QA via a text-to-text transformer framework, and tracks both categorical slots and non-categorical slots in DST. In addition, we introduce two effective ways to construct unanswerable questions, namely, negative question sampling and context truncation, which enable our model to handle none value slots in the zero-shot DST setting. The extensive experiments show that our approaches substantially improve the existing zero-shot and few-shot results on MultiWoz. Moreover, compared to the fully trained baseline on the Schema-Guided Dialogue dataset, our approach shows better generalization ability in unseen domains.
Continual Learning in Task-Oriented Dialogue Systems
Andrea Madotto | Zhaojiang Lin | Zhenpeng Zhou | Seungwhan Moon | Paul Crook | Bing Liu | Zhou Yu | Eunjoon Cho | Pascale Fung | Zhiguang Wang
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Andrea Madotto | Zhaojiang Lin | Zhenpeng Zhou | Seungwhan Moon | Paul Crook | Bing Liu | Zhou Yu | Eunjoon Cho | Pascale Fung | Zhiguang Wang
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Continual learning in task-oriented dialogue systems allows the system to add new domains and functionalities overtime after deployment, without incurring the high cost of retraining the whole system each time. In this paper, we propose a first-ever continual learning benchmark for task-oriented dialogue systems with 37 domains to be learned continuously in both modularized and end-to-end learning settings. In addition, we implement and compare multiple existing continual learning baselines, and we propose a simple yet effective architectural method based on residual adapters. We also suggest that the upper bound performance of continual learning should be equivalent to multitask learning when data from all domain is available at once. Our experiments demonstrate that the proposed architectural method and a simple replay-based strategy perform better, by a large margin, compared to other continuous learning techniques, and only slightly worse than the multitask learning upper bound while being 20X faster in learning new domains. We also report several trade-offs in terms of parameter usage, memory size and training time, which are important in the design of a task-oriented dialogue system. The proposed benchmark is released to promote more research in this direction.
2020
Information Seeking in the Spirit of Learning: A Dataset for Conversational Curiosity
Pedro Rodriguez | Paul Crook | Seungwhan Moon | Zhiguang Wang
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Pedro Rodriguez | Paul Crook | Seungwhan Moon | Zhiguang Wang
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Open-ended human learning and information-seeking are increasingly mediated by digital assistants. However, such systems often ignore the user’s pre-existing knowledge. Assuming a correlation between engagement and user responses such as “liking” messages or asking followup questions, we design a Wizard-of-Oz dialog task that tests the hypothesis that engagement increases when users are presented with facts related to what they know. Through crowd-sourcing of this experiment, we collect and release 14K dialogs (181K utterances) where users and assistants converse about geographic topics like geopolitical entities and locations. This dataset is annotated with pre-existing user knowledge, message-level dialog acts, grounding to Wikipedia, and user reactions to messages. Responses using a user’s prior knowledge increase engagement. We incorporate this knowledge into a multi-task model that reproduces human assistant policies and improves over a bert content model by 13 mean reciprocal rank points.
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Co-authors
- Paul A. Crook 5
- Seungwhan Moon 5
- Eunjoon Cho 4
- Bing Liu 4
- Zhaojiang Lin 3
- Andrea Madotto 3
- Zhou Yu 3
- Zhenpeng Zhou 3
- Pascale Fung 2
- Rajen Subba 2
- Qingsong Wen 2
- Joshua Thomas Bamford 1
- Jiang Bian 1
- Claire Cardie 1
- Yuqiu Deng 1
- Biwei Huang 1
- Haoyang Li 1
- Chenyu Liu 1
- Honglei Liu 1
- Zichuan Liu 1
- Pedro Rodriguez 1
- Stephen Roller 1
- Becka Silvert 1
- Lei Song 1
- Kai Sun 1
- Svitlana Vyetrenko 1
- Yanfeng Wang 1
- Xingjun Wei 1
- Wenyi Wu 1
- Yiyuan Yang 1
- Kai Ying 1
- Chaoli Zhang 1
- Kun Zhou 1
- Xinliang Zhou 1
- Sibo Zhu 1