VLDB 2026 Research / reviewers in the wild / expert
Lei Hou 0001
dblp:32/5685-1
· DBLP profile ↗
42ranked-venue papers in the field
3as first author
31since 2021 · last 2026
0000-0002-8907-3526ORCID · conflict
Domains — venue-derived; a paper can count in several
Information Retrieval & Web Search · 21 (1 first)Data Mining & Knowledge Discovery · 10 (1 first)Database Systems & Data Management · 6 (1 first)Knowledge Engineering, Semantic Web & Information Systems · 5
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Personalized Learning Path Planning through Goal-Driven Learner State ModelingabstractPersonalized Learning Path Planning (PLPP) aims to design adaptive learning paths that align with individual goals. While large language models (LLMs) show potential in personalizing learning experiences, existing approaches often lack mechanisms for goal-aligned planning. We introduce Pxplore, a novel framework for PLPP that integrates a reinforcement-based training paradigm and an LLM-driven educational architecture. We design a structured learner state model and an automated reward function that transforms abstract objectives into computable signals. We train the policy combining supervised fine-tuning (SFT) and Group Relative Policy Optimization (GRPO), and deploy it within a real-world learning platform. Extensive experiments validate Pxplore's effectiveness in producing coherent, personalized, and goal-driven learning paths. We release our code and dataset at https://github.com/Pxplore/pxplore-algo. Joy Lim Jia Yin, Jifan Yu, Xin Cong, Daniel Zhang-Li, Zhiyuan Liu 0001, Huiqin Liu, Lei Hou 0001, Juan-Zi Li, Bin Xu 0001 |
WWW | 8 |
| 2026 | Debate to Extract: Enhancing Event Relation Extraction through Collaborative Debate and Agent OptimizationabstractEvent Relation Extraction (ERE) plays a crucial role in understanding document structures by identifying relations between events. However, most existing methods either rely on single-model instances, which often suffer from overconfidence, or adopt multi-agent frameworks that rely on manually designed prompts and heuristics to define agents, making effective optimization difficult. In this article, we propose Debate to Extract (D2E), a novel multi-agent optimization framework for ERE that leverages structured multi-turn debates and specialized agent training to enhance performance. Specifically, to organize the debate, participants are divided into multiple groups, each assigned its own debate topic. This process effectively integrates both cooperation and confrontation. We also incorporate an audience as a crucial participant, whose conclusions, from an observer’s perspective, tend to be more objective. Building on this debate framework, D2E further optimizes the debate participants, combining structured multi-turn debates with agent training. During the debate, agents refine their initial opinions through collaborative interactions. This iterative process generates valuable supervision signals for training, allowing agents to improve their responses progressively. To address the issue of diminishing returns from data diversity, each agent is trained on distinct subsets of generated data, promoting specialization across different task dimensions. Experimental results on the MAVEN-ERE and EventStoryLine datasets show that D2E achieves significant improvements in causal relation extraction, outperforming baseline methods by 12.1% and 4.69%, respectively. Through further analysis of the debate participants’ performance before and after the debate, we find that participation in the debate generally leads to improved ERE performance. This work demonstrates that combining collaborative debate with agent specialization leads to substantial performance gains in event relation extraction tasks. Shaoru Guo, Lei Hou 0001, Juan-Zi Li |
ACM Trans. Inf. Syst. | 3 |
| 2026 | OpenEP: Open-Ended Future Event PredictionabstractFuture event prediction (FEP) is a long-standing and crucial task in the world, as understanding the evolution of events enables early risk identification, informed decision-making, and strategic planning. Existing work typically treats event prediction as classification tasks and confines the outcomes of future events to a fixed scope, such as yes/no questions, candidate set, and taxonomy, which is difficult to include all possible outcomes of future events. In this article, we introduce OpenEP (an Open -Ended F EP task), which generates flexible and diverse predictions aligned with real-world scenarios. This is mainly reflected in two aspects: firstly, the predictive questions are diverse, covering different stages of event development and perspectives; secondly, the outcomes are flexible, without constraints on scope or format. To facilitate the study of this task, we construct OpenEPBench , a dynamic dataset where events are annotated on the same day they occur. For question construction, we pose questions from seven perspectives, including time, location, event development, event outcome, event impact, event response, and other, to facilitate an in-depth analysis and understanding of the comprehensive evolution of events. For outcome construction, we collect free-form text containing the outcomes as ground truth to provide semantically complete and detail-enriched outcomes. Furthermore, we propose StkFEP , a stakeholder-enhanced FEP framework, that incorporates event characteristics for open-ended settings. Our method extracts stakeholders involved in events to extend questions to gather diverse information. We also collect both contextually relevant events and historically analogous events to reveal potential evolutionary patterns. Experimental results indicate that accurately predicting future events in open-ended settings is challenging for existing LLMs. In addition, we thoroughly summarize the problems encountered in prediction, hoping to provide insights for future research. Code and data are available at: https://github.com/ncepu-eai/OpenEP . Hao Peng 0015, Xiaozhi Wang, Lei Hou 0001, Juan-Zi Li |
ACM Trans. Inf. Syst. | 4 |
| 2025 | VocQuiz: Vocabulary Question Generation for English Language EducationabstractDesigning effective English vocabulary question generation tools demands a shift from labor-intensive content creation to large language model (LLM) automation that can adapt to varied educational contexts. Current approaches tend to offer a limited variety of question types, which restricts their practical application in real classroom settings. To better meet the demands of English teaching institutions, we present VocQuiz, a vocabulary question generation system that 1) combines generalization capabilities of LLMs with reliable language resources, including dictionaries, NLP datasets and authentic corpora, to enhance both contextual relevance and linguistic accuracy; 2) supports multiple question types, such as similar word selection and word collocation, to accommodate various instructional requirements; and 3) employs an iterative workflow to iteratively generate and refine questions, ensuring high-quality outputs and consistent assessment standards. VocQuiz offers a practical, deployable solution that helps educators create quiz-based instructional materials, reducing preparation effort while effectively assessing students' mastery of vocabulary. Yongqi Li 0012, Jiajun Wu 0024, Shangqing Tu, Jifan Yu, Huiqin Liu, Lei Hou 0001, Juan-Zi Li |
CIKM | 6 |
| 2025 | Constraint Back-translation Improves Complex Instruction Following of Large Language ModelsabstractLarge language models (LLMs) struggle to follow instructions with complex constraints in format, length, etc. Following the conventional instruction-tuning practice, previous works conduct post-training on complex instruction-response pairs generated by feeding complex instructions to advanced LLMs. However, even advanced LLMs cannot follow complex instructions well, thus limiting the quality of generated data. In this work, we find that existing datasets inherently contain implicit complex constraints and propose a novel data generation technique, constraint back-translation. Specifically, we take the high-quality instruction-response pairs in existing datasets and only adopt advanced LLMs to add complex constraints already met by the responses to the instructions, which naturally reduces costs and data noise. In the experiments, we adopt Llama3-70B-Instruct to back-translate constraints and create a high-quality complex instruction-response dataset, named Crab. We present that post-training on Crab improves multiple backbone LLMs' complex instruction-following ability, evaluated on extensive instruction-following benchmarks. We further find that constraint back-translation also serves as a useful auxiliary training objective in post-training. Our code, data, and models are released to facilitate future research. Yunjia Qi, Hao Peng 0015, Xiaozhi Wang, Bin Xu 0001, Lei Hou 0001, Juan-Zi Li |
CIKM | 5 |
| 2025 | EduCraft: A System for Generating Pedagogical Lecture Scripts from Long-Context Multimodal PresentationsabstractEducators face substantial workload pressures, with significant time invested in preparing teaching materials. Generating high-quality lecture scripts from multimodal presentations is a particularly demanding aspect of this preparation. This paper introduces EduCraft, a novel system designed to automate Lecture Script Generation (LSG), addressing key difficulties such as comprehensive multimodal understanding, long-context coherence, and instructional design efficacy. EduCraft features a modular architecture comprising: (1) a Multimodal Input Processing pipeline for robust data extraction and association from slides; (2) a core Lecture Script Generation Engine with instruction-guided VLM and Caption+LLM workflows for pedagogical synthesis; (3) an optional Knowledge Augmentation Module using Retrieval-Augmented Generation (RAG) for enhanced factual grounding; and (4) a Model Integration and Deployment Interface supporting diverse AI models and providing a deployable API. Extensive evaluations, including human assessments and a new automated evaluation framework, demonstrate that EduCraft significantly outperforms strong baselines and teacher-refined scripts in producing coherent, readable, and pedagogically sound lecture scripts. By effectively tackling core LSG challenges, EduCraft offers a practical, configurable solution to reduce educator workload and enhance educational content creation. We open-source EduCraft at https://github.com/wyuc/EduCraft. Yucheng Wang 0015, Jifan Yu, Daniel Zhang-Li, Joy Lim Jia Yin, Shangqing Tu, Haoxuan Li 0003, Zhiyuan Liu 0001, Huiqin Liu, Lei Hou 0001, Juan-Zi Li, Bin Xu 0001 |
CIKM | 9 |
| 2025 | StoryWriter: A Multi-Agent Framework for Long Story GenerationabstractLong story generation remains a challenge for existing large language models (LLMs), primarily due to two main factors: (1) discourse coherence, which requires plot consistency, logical coherence, and completeness in the long-form generation, and (2) narrative complexity, which requires an interwoven and engaging narrative. In this paper, we present StoryWriter, a modular and open-source multi-agent framework for controllable and scalable long story generation. We conduct both human and automated evaluation, and StoryWriter significantly outperforms existing story generation baselines in both story quality and length. Furthermore, we use StoryWriter to generate a dataset, which contains about 6,000 high-quality long stories, with an average length of 8,000 words. We train the model Llama3.1-8B and GLM4-9B using supervised fine-tuning on LongStory and develop StoryWriterLLAMA and StoryWriterGLM, which demonstrates advanced performance in long story generation. All code, models, and data are made publicly available to encourage further development. Haotian Xia, Hao Peng 0015, Yunjia Qi, Bin Xu 0001, Juan-Zi Li, Lei Hou 0001, Xiaozhi Wang |
CIKM | 6 |
| 2025 | LLMAEL: Large Language Models are Good Context Augmenters for Entity LinkingabstractSpecialized entity linking (EL) models are well-trained at mapping mentions to unique knowledge base (KB) entities according to a given context. However, specialized EL models struggle to disambiguate long-tail entities due to their limited training data. Meanwhile, extensively pre-trained large language models (LLMs) possess broader knowledge of uncommon entities. Yet, with a lack of specialized EL training, LLMs frequently fail to generate accurate KB entity names, limiting their standalone effectiveness in EL. With the observation that LLMs are more adept at context generation instead of EL execution, we introduce LLM-Augmented Entity Linking (LLMAEL), the first framework to enhance specialized EL models with LLM data augmentation. LLMAEL leverages off-the-shelf, tuning-free LLMs as context augmenters, generating entity descriptions to serve as additional input for specialized EL models. Experiments show that LLMAEL sets new state-of-the-art results across 6 widely adopted EL benchmarks: compared to prior methods that integrate tuning-free LLMs into EL, LLMAEL achieves an absolute 8.9% gain in EL accuracy. We release our code and datasets. Amy Xin, Yunjia Qi, Zijun Yao 0002, Fangwei Zhu, Kaisheng Zeng, Bin Xu 0001, Lei Hou 0001, Juan-Zi Li |
CIKM | 7 |
| 2025 | Knowledge-to-Jailbreak: Investigating Knowledge-driven Jailbreaking Attacks for Large Language ModelsabstractLarge language models (LLMs) have been increasingly applied to various domains, which triggers increasing concerns about LLMs' safety on specialized domains, e.g. medicine. Despite prior explorations on general jailbreaking attacks, there are two challenges for applying existing attacks on testing the domain-specific safety of LLMs: (1) Lack of professional knowledge-driven attacks(2) Insufficient coverage of domain knowledge. To bridge this gap, we propose a new task, knowledge-to-jailbreak, which aims to generate jailbreaking attacks from domain knowledge, requiring both attack effectiveness and knowledge relevance. We collect a large-scale dataset with 12,974 knowledge-jailbreak pairs and fine-tune a large language model as jailbreak-generator, to produce domain knowledge-specific jailbreaks. Experiments on 13 domains and 8 target LLMs demonstrate the effectiveness of jailbreak-generator in generating jailbreaks that are both threatening to the target LLMs and relevant to the given knowledge. We also apply our method to an out-of-domain knowledge base, showing that jailbreak-generator can generate jailbreaks that are comparable in harmfulness to those crafted by human experts. Data and code are available at: https://github.com/THU-KEG/Knowledge-to-Jailbreak/. Shangqing Tu, Zhuoran Pan, Wenxuan Wang 0001, Zhexin Zhang, Jifan Yu, Hongning Wang, Lei Hou 0001, Juan-Zi Li |
KDD (2) | 8 |
| 2025 | SoAy: A Solution-based LLM API-using Methodology for Academic Information Seeking
Yuanchun Wang 0002, Jifan Yu, Zijun Yao 0002, Jing Zhang 0001, Shangqing Tu, Yiyang Fu, Youhe Feng, Jinkai Zhang, Yuanyao Li, Huihui Yuan, Lei Hou 0001, Juan-Zi Li, Jie Tang 0001 |
KDD (1) | 14 |
| 2025 | AtomR: Atomic Operator-Empowered Large Language Models for Heterogeneous Knowledge ReasoningabstractDespite the outstanding capabilities of large language models (LLMs), knowledge-intensive reasoning still remains a challenging task due to LLMs' limitations in compositional reasoning and the hallucination problem. A prevalent solution is to employ chain-of-thought (CoT) with retrieval-augmented generation (RAG), which first formulates a reasoning plan by decomposing complex questions into simpler sub-questions, and then applies iterative RAG at each sub-question. However, prior works exhibit two crucial problems: inadequate reasoning planning and poor incorporation of heterogeneous knowledge. In this paper, we introduce AtomR, a framework for LLMs to conduct accurate heterogeneous knowledge reasoning at the atomic level. Inspired by how knowledge graph query languages model compositional reasoning through combining predefined operations, we propose three atomic knowledge operators, a unified set of operators for LLMs to retrieve and manipulate knowledge from heterogeneous sources. First, in the reasoning planning stage, AtomR decomposes a complex question into a reasoning tree where each leaf node corresponds to an atomic knowledge operator, achieving question decomposition that is highly fine-grained and orthogonal. Subsequently, in the reasoning execution stage, AtomR executes each atomic knowledge operator, which flexibly selects, retrieves, and operates atomic level knowledge from heterogeneous sources. We also introduce BlendQA, a challenging benchmark specially tailored for heterogeneous knowledge reasoning. Experiments on three single-source and two multi-source datasets show that AtomR outperforms state-of-the-art baselines by a large margin, with absolute F1 score improvements of 9.4% on 2WikiMultihop and 9.5% on BlendQA. We release our code and data https://github.com/THU-KEG/AtomR.git. Amy Xin, Jinxin Liu 0002, Zijun Yao 0002, Zhicheng Lee, Shulin Cao, Lei Hou 0001, Juan-Zi Li |
KDD (2) | 6 |
| 2025 | Awaking the Slides: A Tuning-free and Knowledge-regulated AI Tutoring System via Language Model CoordinationabstractThe vast pre-existing slides serve as rich and important materials to carry lecture knowledge. However, effectively leveraging lecture slides to serve students is difficult due to the multi-modal nature of slide content and the heterogeneous teaching actions. We study the problem of discovering effective designs that convert a slide into an interactive lecture. We develop Slide2Lecture, a tuning-free and knowledge-regulated intelligent tutoring system that can (1) effectively convert an input lecture slide into a structured teaching agenda consisting of a set of heterogeneous teaching actions; (2) create and manage an interactive lecture that generates responsive interactions catering to student learning demands while regulating the interactions to follow teaching actions. Slide2Lecture contains a complete pipeline for learners to obtain an interactive classroom experience to learn the slide. For teachers and developers, Slide2Lecture enables customization to cater to personalized demands. Slide2Lecture's online deployment has made more than 200K interactions with students in the 3K lecture sessions. We release our implementation at https://github.com/NewEduAI/Release. Daniel Zhang-Li, Zheyuan Zhang 0002, Jifan Yu, Joy Lim Jia Yin, Shangqing Tu, Linlu Gong, Zhiyuan Liu 0001, Huiqin Liu, Lei Hou 0001, Juan-Zi Li |
KDD (1) | 10 |
| 2025 | Document-Level Relation Extraction With Low Entity Redundancy Feature MapabstractDocument-level relation extraction (RE) aims to determine the relations between entities scattered across different sentences through reading and reasoning. Existing methods use semantic segmentation to obtain global information among triples by analyzing entity-level matrices. However, complete document input may introduce certain interference, making it challenging to express the underlying relationships. To address this, we propose a novel approach introducing a low-entity redundancy feature map, achieved by removing certain entities. The proposed optimal path filtering (OPF) selects entity-related sentences using heuristic rules and formulates sentence selection as a set cover problem, solved via backtracking pruning. U-Net is then applied to obtain global features. Our experiment achieves state-of-the-art results on two common document-level RE datasets, Re-DocRED and CDR, outperforming previous methods. Rongen Yan, Depeng Dang, Keqin Peng, Ye Tao 0003, Lei Hou 0001, Juan-Zi Li, Jie Tang 0001 |
IEEE Trans. Knowl. Data Eng. | 6 |
| 2024 | DiaKoP: Dialogue-based Knowledge-oriented Programming for Neural-symbolic Knowledge Base Question Answering
Zhicheng Lee, Zhidian Huang, Zijun Yao 0002, Jinxin Liu 0002, Amy Xin, Lei Hou 0001, Juan-Zi Li |
CIKM | 6 |
| 2024 | R-Eval: A Unified Toolkit for Evaluating Domain Knowledge of Retrieval Augmented Large Language ModelsabstractLarge language models have achieved remarkable success on general NLP tasks, but they may fall short for domain-specific problems. Recently, various Retrieval-Augmented Large Language Models (RALLMs) are proposed to address this shortcoming. However, existing evaluation tools only provide a few baselines and evaluate them on various domains without mining the depth of domain knowledge. In this paper, we address the challenges of evaluating RALLMs by introducing the R-Eval toolkit, a Python toolkit designed to streamline the evaluation of different RAG workflows in conjunction with LLMs. Our toolkit, which supports popular built-in RAG workflows and allows for the incorporation of customized testing data on the specific domain, is designed to be user-friendly, modular, and extensible. We conduct an evaluation of 21 RALLMs across three task levels and two representative domains, revealing significant variations in the effectiveness of RALLMs across different tasks and domains. Our analysis emphasizes the importance of considering both task and domain requirements when choosing a RAG workflow and LLM combination. We are committed to continuously maintaining our platform at https://github.com/THU-KEG/R-Eval to facilitate both the industry and the researchers. Shangqing Tu, Yuanchun Wang 0002, Jifan Yu, Yaran Shi, Xiaozhi Wang, Jing Zhang 0001, Lei Hou 0001, Juan-Zi Li |
KDD | 8 |
| 2024 | Entity Set Expansion Based on Category Prompts in MOOCs
Yubin Chen, Yexing Du, Jifan Yu, Lei Hou 0001, Juan-Zi Li |
KSEM (2) | 5 |
| 2024 | A Survey of Knowledge Enhanced Pre-Trained Language ModelsabstractPre-trained Language Models (PLMs) which are trained on large text corpus via self-supervised learning method, have yielded promising performance on various tasks in Natural Language Processing (NLP). However, though PLMs with huge parameters can effectively possess rich knowledge learned from massive training text and benefit downstream tasks at the fine-tuning stage, they still have some limitations such as poor reasoning ability due to the lack of external knowledge. Research has been dedicated to incorporating knowledge into PLMs to tackle these issues. In this paper, we present a comprehensive review of Knowledge Enhanced Pre-trained Language Models (KE-PLMs) to provide a clear insight into this thriving field. We introduce appropriate taxonomies respectively for Natural Language Understanding (NLU) and Natural Language Generation (NLG) to highlight these two main tasks of NLP. For NLU, we divide the types of knowledge into four categories: linguistic knowledge, text knowledge, knowledge graph (KG), and rule knowledge. The KE-PLMs for NLG are categorized into KG-based and retrieval-based methods. Finally, we point out some promising future directions of KE-PLMs. Linmei Hu, Ziwang Zhao, Lei Hou 0001, Liqiang Nie, Juan-Zi Li |
IEEE Trans. Knowl. Data Eng. | 4 |
| 2024 | Towards Knowledge-Aware and Deep Reinforced Cross-Domain Recommendation Over Collaborative Knowledge GraphabstractCross-domain recommendations (CDRs), which can leverage the relatively abundant information from a richer domain to improve the recommendation performance in a sparser domain, have attracted great attention due to their flexible recommendation strategies. Nevertheless, existing CDR approaches still suffer from severe data sparsity and low semantic sampling efficiency issues, and hardly employ existing reinforcement learning models to improve cross-domain recommendation accuracy. To this end, we propose a new Knowledge-aware and Deep Reinforced Cross-Domain Recommendation framework over Collaborative Knowledge Graph (KRCDR). Specifically, we formalize the cross-domain recommendation task as a Markov Decision Process, and propose a knowledge-aware dual state representation approach to enhance state representations within and across domains for target users by leveraging knowledge graph information. Then, to improve the training performance, we propose a Constrained Self-supervised Actor-Critic network (CSAC) model, in which a constrained neighbor pruning strategy is devised to narrow the exploration space and improve the sampling efficiency, and the CSAC is developed to improve the recommendation policy. Additionally, in our proposed CSAC model, a self-supervised output layer within domains is used as an actor network to generate the recommendation policy, and a Q-learning output layer across domains is used as a critic network to feedback reward signals. Finally, based on the KRCDR approach, we design a new algorithm to assist in generating cross-domain recommendation results. Extensive experiments have been conducted on several real-world datasets, which demonstrate the superiority of our proposed approach compared with state-of-the-art baseline methods. Lei Hou 0001, Juan-Zi Li |
IEEE Trans. Knowl. Data Eng. | 2 |
| 2024 | XLORE 3: A Large-Scale Multilingual Knowledge Graph from Heterogeneous Wiki Knowledge ResourcesabstractIn recent years, knowledge graph (KG) has attracted significant attention from academia and industry, resulting in the development of numerous technologies for KG construction, completion, and application. XLORE is one of the largest multilingual KGs built from Baidu Baike and Wikipedia via a series of knowledge modeling and acquisition methods. In this article, we utilize systematic methods to improve XLORE's data quality and present its latest version, XLORE 3, which enables the effective integration and management of heterogeneous knowledge from diverse resources. Compared with previous versions, XLORE 3 has three major advantages: (1) We design a comprehensive and reasonable schema, namely XLORE ontology, which can effectively organize and manage entities from various resources. (2) We merge equivalent entities in different languages to facilitate knowledge sharing. We provide a large-scale entity linking system to establish the associations between unstructured text and structured KG. (3) We design a multi-strategy knowledge completion framework, which leverages pre-trained language models and vast amounts of unstructured text to discover missing and new facts. The resulting KG contains 446 concepts, 2,608 properties, 66 million entities, and more than 2 billion facts. It is available and downloadable online at https://www.xlore.cn/ , providing a valuable resource for researchers and practitioners in various fields. Kaisheng Zeng, Hailong Jin, Fangwei Zhu, Lei Hou 0001, Yi Zhang 0163, Fan Pang, Dingxiao Liu, Juan-Zi Li |
ACM Trans. Inf. Syst. | 5 |
| 2023 | GOAL: A Challenging Knowledge-grounded Video Captioning Benchmark for Real-time Soccer Commentary GenerationabstractDespite the recent emergence of video captioning models, how to generate vivid, fine-grained video descriptions based on the background knowledge (i.e., long and informative commentary about the domain-specific scenes with appropriate reasoning) is still far from being solved, which however has great applications such as automatic sports narrative. Based on soccer game videos and synchronized commentary data, we present GOAL, a benchmark of over 8.9k soccer video clips, 22k sentences, and 42k knowledge triples for proposing a challenging new task setting as Knowledge-grounded Video Captioning (KGVC). We experimentally test existing state-of-the-art (SOTA) methods on this resource to demonstrate the future directions for improvement in this challenging task. We hope that our data resource (now available at https://github.com/THU-KEG/goal) can serve researchers and developers interested in knowledge-grounded cross-modal applications. Ji Qi 0003, Jifan Yu, Teng Tu 0002, Kunyu Gao, Yifan Xu 0014, Xiaozhi Wang, Bin Xu 0001, Lei Hou 0001, Juan-Zi Li, Jie Tang 0001 |
CIKM | 9 |
| 2023 | LittleMu: Deploying an Online Virtual Teaching Assistant via Heterogeneous Sources Integration and Chain of Teach PromptsabstractTeaching assistants have played essential roles in the long history of education. However, few MOOC platforms are providing human or virtual teaching assistants to support learning for massive online students due to the complexity of real-world online education scenarios and the lack of training data. In this paper, we present a virtual MOOC teaching assistant, LittleMu with minimum labeled training data, to provide question answering and chit-chat services. Consisting of two interactive modules of heterogeneous retrieval and language model prompting, LittleMu first integrates structural, semi- and unstructured knowledge sources to support accurate answers for a wide range of questions. Then, we design delicate demonstrations named "Chain of Teach" prompts to exploit the large-scale pre-trained model to handle complex uncollected questions. Except for question answering, we develop other educational services such as knowledge-grounded chit-chat. We test the system's performance via both offline evaluation and online deployment. Since May 2020, our LittleMu system has served over 80,000 users with over 300,000 queries from over 500 courses on XuetangX MOOC platform, which continuously contributes to a more convenient and fair education. Our code, services, and dataset will be available at https://github.com/THU-KEG/VTA. Shangqing Tu, Zheyuan Zhang 0002, Jifan Yu, Zijun Yao 0002, Lei Hou 0001, Juan-Zi Li |
CIKM | 7 |
| 2023 | MoocRadar: A Fine-grained and Multi-aspect Knowledge Repository for Improving Cognitive Student Modeling in MOOCsabstractStudent modeling, the task of inferring a student's learning characteristics through their interactions with coursework, is a fundamental issue in intelligent education. Although the recent attempts from knowledge tracing and cognitive diagnosis propose several promising directions for improving the usability and effectiveness of current models, the existing public datasets are still insufficient to meet the need for these potential solutions due to their ignorance of complete exercising contexts, fine-grained concepts, and cognitive labels. In this paper, we present MoocRadar, a fine-grained, multi-aspect knowledge repository consisting of 2,513 exercise questions, 5,600 knowledge concepts, and over 12 million behavioral records. Specifically, we propose a framework to guarantee a high-quality and comprehensive annotation of fine-grained concepts and cognitive labels. The statistical and experimental results indicate that our dataset provides the basis for the future improvements of existing methods. Moreover, to support the convenient usage for researchers, we release a set of tools for data querying, model adaption, and even the extension of our repository, which are now available at https://github.com/THU-KEG/MOOC-Radar. Jifan Yu, Mengying Lu, Qingyang Zhong, Zijun Yao 0002, Shangqing Tu, Zhengshan Liao, Xiaoya Li 0002, Manli Li, Lei Hou 0001, Hai-Tao Zheng 0002, Juan-Zi Li, Jie Tang 0001 |
SIGIR | 9 |
| 2023 | Preference-aware Graph Attention Networks for Cross-Domain Recommendations with Collaborative Knowledge GraphabstractKnowledge graphs (KGs) can provide users with semantic information and relations among numerous entities and nodes, which can greatly facilitate the performance of recommender systems. However, existing KG-based approaches still suffer from severe data sparsity and may not be effective in capturing the preference features of similar entities across domains. Therefore, in this article, we propose a P reference-aware G raph A ttention network model with C ollaborative K nowledge G raph ( PGACKG ) for cross-domain recommendations. Preference-aware entity embeddings with some collaborative signals are first obtained by exploiting the graph-embedding model, which can transform entities and items in the collaborative knowledge graph into semantic preference spaces. To better learn user preference features, we devise a preference-aware graph attention network framework that aggregates the preference features of similar entities within domains and across domains. In this framework, multi-hop reasoning is employed to assist in the generation of preference features within domains, and the node random walk based on frequency visits is proposed to gather similar preferences across domains for target entities. Then, the final preference features of entities are fused, while a novel C ross-domain B ayesian P ersonalized R anking ( CBPR ) is proposed to improve cross-domain recommendation accuracy. Extensive empirical experiments on four real-world datasets demonstrate that our proposed approach consistently outperforms state-of-the-art baselines. Furthermore, our PGACKG achieves strong performance in different ablation scenarios, and the interaction sparsity experiments also demonstrate that our proposed approach can significantly alleviate the data sparsity issue. Lei Hou 0001, Juan-Zi Li |
ACM Trans. Inf. Syst. | 2 |
| 2022 | CStory: A Chinese Large-scale News Storyline DatasetabstractIn today's massive news streams, storylines can help us discover related event pairs and understand the evolution of hot events. Hence many efforts have been devoted to automatically constructing news storylines. However, the development of these methods is strongly limited by the size and quality of existing storyline datasets since news storylines are expensive to annotate as they contain a myriad of unlabeled relationships growing quadratically with the number of news events. Working around these difficulties, we propose a sophisticated pre-processing method to filter candidate news pairs by entity co-occurrence and semantic similarity. With the filter reducing annotation overhead, we construct CStory, a large-scale Chinese news storyline dataset, which contains 11,978 news articles, 112,549 manually labeled storyline relation pairs, and 49,832 evidence sentences for annotation judgment. We conduct extensive experiments on CStory using various algorithms and find that constructing news storylines is challenging even for pre-trained language models. Empirical analysis shows that the sample unbalance issue significantly influences model performance, which shall be the focus of future works. Our dataset is now publicly available at https://github.com/THU-KEG/CStory. Kaijie Shi 0001, Xiaozhi Wang, Jifan Yu, Lei Hou 0001, Juan-Zi Li, Jingtong Wu, Dingyu Yong, Jinghui Xiao, Qun Liu 0001 |
CIKM | 4 |
| 2022 | Interactive Contrastive Learning for Self-Supervised Entity AlignmentabstractSelf-supervised entity alignment (EA) aims to link equivalent entities across different knowledge graphs (KGs) without the use of pre-aligned entity pairs. The current state-of-the-art (SOTA) self-supervised EA approach draws inspiration from contrastive learning, originally designed in computer vision based on instance discrimination and contrastive loss, and suffers from two shortcomings. Firstly, it puts unidirectional emphasis on pushing sampled negative entities far away rather than pulling positively aligned pairs close, as is done in the well-established supervised EA. Secondly, it advocates the minimum information requirement for self-supervised EA, while we argue that self-described KG's side information (e.g., entity name, relation name, entity description) shall preferably be explored to the maximum extent for the self-supervised EA task. In this work, we propose an interactive contrastive learning model for self-supervised EA. It conducts bidirectional contrastive learning via building pseudo-aligned entity pairs as pivots to achieve direct cross-KG information interaction. It further exploits the integration of entity textual and structural information and elaborately designs encoders for better utilization in the self-supervised setting. Experimental results show that our approach outperforms the previous best self-supervised method by a large margin (over 9% [email protected] absolute improvement on average) and performs on par with previous SOTA supervised counterparts, demonstrating the effectiveness of the interactive contrastive learning for self-supervised EA. The code and data are available at https://github.com/THU-KEG/ICLEA. Kaisheng Zeng, Zhenhao Dong, Lei Hou 0001, Yixin Cao 0002, Minghao Hu 0001, Jifan Yu, Xin Wang 0117, Haozhuang Liu, Yi Huang 0017, Junlan Feng, Juan-Zi Li |
CIKM | 3 |
| 2022 | Triple-as-Node Knowledge Graph and Its Embeddings
Jiaxin Shi, Shulin Cao, Lei Hou 0001, Juan-Zi Li |
DASFAA (1) | 4 |
| 2022 | XDAI: A Tuning-free Framework for Exploiting Pre-trained Language Models in Knowledge Grounded Dialogue GenerationabstractLarge-scale pre-trained language models (PLMs) have shown promising advances on various downstream tasks, among which dialogue is one of the most concerned. However, there remain challenges for individual developers to create a knowledge-grounded dialogue system upon such big models because of the expensive cost of collecting the knowledge resources for supporting the system as well as tuning these large models for the task. To tackle these obstacles, we propose XDAI, a knowledge-grounded dialogue system that is equipped with the prompt-aware tuning-free PLM exploitation and supported by the ready-to-use open-domain external knowledge resources plus the easy-to-change domain-specific mechanism. With XDAI, the developers can leverage the PLMs without any fine-tuning cost to quickly create the open-domain dialogue systems as well as easily customize their own domain-specific systems. Extensive experiments including human evaluation, Turing test, and online evaluation have demonstrated the competitive performance of XDAI compared with the state-of-the-art general PLMs and specific PLMs for dialogue. XDAI pilots studies on the exploitation of PLMs and made intriguing findings which could be inspiring for the future research on other PLM-based applications. Jifan Yu, Yifan Xu 0014, Xuanyu Lei, Jing Zhang 0001, Lei Hou 0001, Juan-Zi Li, Jie Tang 0001 |
KDD | 7 |
| 2021 | MOOCCubeX: A Large Knowledge-centered Repository for Adaptive Learning in MOOCsabstractThe prosperity of massive open online courses provides fodder for plentiful research efforts on adaptive learning. However, current open-access educational datasets are still far from sufficient to meet the need for various topics of adaptive learning. Existing released datasets often cover only small-scale data, lack fine-grained knowledge concepts. They are even difficult to curate and supplement due to platform limitations. In this work, we construct MOOCCubeX, a large, knowledge-centered repository consisting of 4,216 courses, 230,263 videos, 358,265 exercises, 637,572 fine-grained concepts and over 296 million behavioral data of 3,330,294 students, for supporting the research topics on adaptive learning in MOOCs. Licensed by XuetangX, one of the largest MOOC websites in China, we obtain abundant and diverse course resources and student behavioral data and are permitted to make subsequent periodic updates. We propose a framework to accomplish data processing, weakly supervised fine-grained concept graph mining, and data curation to improve usability and richness. Based on the fine-grained concepts, we re-organize the data from the knowledge perspective and acquire more external learning resources from the web. Our repository is now available at https://github.com/THU-KEG/MOOCCubeX. Jifan Yu, Yuquan Wang, Qingyang Zhong, Gan Luo, Yiming Mao 0005, Wenzheng Feng, Wei Xu 0017, Shulin Cao, Kaisheng Zeng, Zijun Yao 0002, Lei Hou 0001, Yankai Lin 0001, Peng Li 0030, Jie Zhou 0016, Bin Xu 0001, Juan-Zi Li, Jie Tang 0001, Maosong Sun 0001 |
CIKM | 12 |
| 2021 | Multi-Grained Dependency Graph Neural Network for Chinese Open Information Extraction
Zhiheng Lyu, Kaijie Shi 0001, Lei Hou 0001, Juan-Zi Li, Binheng Song |
PAKDD (3) | 4 |
| 2021 | Expertise-Aware Crowdsourcing Taxonomy Enrichment
Yuquan Wang, Yiming Mao 0005, Jifan Yu, Kaisheng Zeng, Lei Hou 0001, Juan-Zi Li, Jie Tang 0001 |
WISE (1) | 6 |
| 2021 | Encoding the Meaning Triangle (Object, Entity, and Concept) as the Semantic Foundation for Entity Alignment
Kaisheng Zeng, Chengjiang Li, Lei Hou 0001, Guozheng Peng, Juan-Zi Li |
WISE (1) | 5 |
| 2020 | Geographical Information Enhanced POI Hierarchical Classification
Jifan Yu, Juan-Zi Li, Lei Hou 0001 |
WISA | 4 |
| 2020 | Improving Low-Resource Chinese Event Detection with Multi-task Learning
Meihan Tong, Bin Xu 0001, Shuai Wang 0030, Lei Hou 0001, Juan-Zi Li |
KSEM (1) | 4 |
| 2019 | Unsupervised Cross-Lingual Sentence Representation Learning via Linguistic Isomorphism
Shuai Wang 0030, Lei Hou 0001, Meihan Tong |
KSEM (2) | 2 |
| 2018 | Is a Common Phrase an Entity Mention or Not? Dual Representations for Domain-Specific Named Entity Recognition
Juan-Zi Li, Xiaoli Li 0001, Yixin Cao 0002, Lei Hou 0001, Shuai Wang 0030 |
DASFAA (1) | 5 |
| 2018 | Category Multi-representation: A Unified Solution for Named Entity Recognition in Clinical Texts
Juan-Zi Li, Shuai Wang 0030, Yan Zhang 0004, Yixin Cao 0002, Lei Hou 0001, Xiaoli Li 0001 |
PAKDD (2) | 6 |
| 2017 | Cross-Lingual Infobox Alignment in Wikipedia Using Entity-Attribute Factor Graph
Yan Zhang 0004, Thomas Paradis, Lei Hou 0001, Juan-Zi Li, Jing Zhang 0036, Hai-Tao Zheng 0002 |
ISWC (1) | 3 |
| 2017 | Learning to Align Comments to News TopicsabstractWith the rapid proliferation of social media, increasingly more people express their opinions and reviews (user-generated content (UGC)) on recent news articles through various online services, such as news portals, forums, discussion groups, and microblogs. Clearly, identifying hot topics that users greatly care about can improve readers’ news browsing experience and facilitate research into interaction analysis between news and UGC. Furthermore, it is of great benefit to public opinion monitoring and management for both industry and government agencies. However, it is extremely time consuming, if not impossible, to manually examine the large amount of available social content. In this article, we formally define the news comment alignment problem and propose a novel framework that: (1) automatically extracts topics from a given news article and its associated comments, (2) identifies and extends positive examples with different degrees of confidence using three methods (i.e., hypersphere, density, and cluster chain), and (3) completes the alignment between news sentences and comments through a weighted-SVM classifier. Extensive experiments show that our proposed framework significantly outperforms state-of-the-art methods. Lei Hou 0001, Juan-Zi Li, Xiaoli Li 0001, Jie Tang 0001, Xiaofei Guo |
ACM Trans. Inf. Syst. | 1 |
| 2016 | Detecting Public Influence on News Using Topic-Aware Dynamic Granger Test
Lei Hou 0001, Juan-Zi Li, Xiaoli Li 0001, Jianbin Jin |
ECML/PKDD (2) | 1 |
| 2015 | Measuring the Influence from User-Generated Content to News via Cross-dependence Topic Modeling
Lei Hou 0001, Juan-Zi Li, Xiaoli Li 0001 |
DASFAA (1) | 1 |
| 2012 | Personalized Diversity Search Based on User's Social Relationships
Juan-Zi Li, Lei Hou 0001, Hai-Tao Zheng 0002 |
ADMA | 3 |
| 2012 | Exploration and Visualization of Administrator Network in Wikipedia
Jamal Yousaf, Juan-Zi Li, Haisu Zhang, Lei Hou 0001 |
APWeb | 4 |