Be More with Less: Hypergraph Attention Networks for Inductive Text Classification

TL;DR

HyperGAT leverages hypergraph attention to improve text classification, achieving over 86% accuracy on benchmark datasets.

cs.CL 🔴 Advanced 2020-11-01 55 views
Kaize Ding Jianling Wang Jundong Li Dingcheng Li Huan Liu
Graph Neural Networks Hypergraph Text Classification Attention Mechanism Deep Learning

Key Findings

Methodology

This paper introduces HyperGAT, a hypergraph-based neural network that employs dual attention mechanisms at node and hyperedge levels to capture high-order word interactions. Each document is modeled as a hypergraph with words as nodes and sentences or topics as hyperedges, constructed via sliding windows and LDA. The model stacks multiple layers, each performing node-to-hyperedge and hyperedge-to-node attention, enabling deep semantic feature extraction. The final document representation is obtained through pooling, which feeds into a classifier. Extensive experiments on datasets like 20NG, R8, R52, Ohsumed, and MR demonstrate superior performance over state-of-the-art baselines.

Key Results

  • HyperGAT achieves average accuracies of 86.62% on 20NG, 97.97% on R8, 94.98% on R52, 69.90% on Ohsumed, and 78.32% on MR, surpassing previous models such as TextGCN and CNN by 2-4 percentage points.
  • Memory analysis shows HyperGAT reduces memory consumption by approximately 70% compared to transductive models like TextGCN, owing to document-level hypergraph construction.
  • Ablation studies confirm that both node and hyperedge attention significantly contribute to performance, with removal leading to 1-2% accuracy drops, highlighting the importance of high-order interaction modeling.

Significance

This work advances the field by addressing the limitations of existing GNNs in capturing complex semantic relations and computational scalability. HyperGAT’s hypergraph structure effectively models multi-word dependencies and thematic relations, enabling more expressive text representations. Its inductive capability allows for efficient handling of unseen documents, making it suitable for real-world applications like content filtering, sentiment analysis, and large-scale information retrieval. The approach paves the way for scalable, high-accuracy NLP systems that leverage high-order semantic structures.

Technical Contribution

The key technical innovation is the integration of hypergraph structures with dual attention mechanisms, enabling the model to learn rich, high-order word interactions efficiently. Unlike traditional GNNs limited to pairwise relations, HyperGAT captures multi-word dependencies via hyperedges, supported by attention modules that dynamically weigh node and hyperedge importance. The model’s architecture facilitates deep feature extraction while maintaining computational efficiency, representing a significant step forward in hypergraph neural network design for NLP.

Novelty

This is the first application of hypergraph neural networks to text classification, introducing a novel hyperedge construction method that connects multiple words simultaneously. The dual attention mechanism uniquely highlights relevant nodes and hyperedges at different levels, enabling the capture of complex semantic relations that previous pairwise models cannot. This combination of hypergraph modeling and attention mechanisms offers a new paradigm for high-order semantic learning in NLP.

Limitations

  • The hypergraph construction relies on external topic models like LDA, which may introduce bias or inaccuracies, especially on noisy or very long texts.
  • In extremely large documents with dense hyperedges, computational complexity may still increase significantly, requiring further optimization.
  • The model’s performance may degrade on texts with ambiguous or highly noisy hyperedges, necessitating more robust hyperedge selection strategies.

Future Work

Future directions include integrating dynamic hypergraphs that adapt during training, exploring multi-modal hypergraph structures combining text with other data types, and developing more scalable hyperedge sampling techniques. Additionally, enhancing the hypergraph construction process with learned hyperedge selection could further improve efficiency and accuracy, broadening the applicability of HyperGAT in real-time NLP tasks.

AI Executive Summary

Text classification remains a fundamental challenge in natural language processing, with traditional sequence models like CNNs and LSTMs excelling at local context but struggling with long-distance dependencies. Graph neural networks (GNNs) introduced a new perspective by modeling words and documents as nodes in a graph, capturing global relationships. However, these models are often limited to pairwise interactions, which restricts their ability to encode complex semantic structures. Moreover, constructing large, global graphs is computationally expensive and hampers scalability.

To overcome these issues, this research proposes HyperGAT, a hypergraph attention network that models each document as a hypergraph, where words are nodes and sentences or topics form hyperedges. This structure naturally captures high-order relationships, such as multi-word expressions and thematic connections. The core innovation lies in the dual attention mechanism—node-level and hyperedge-level attention—that dynamically emphasizes important words and hyperedges, enabling the model to learn rich, context-aware representations.

Experimental results on five benchmark datasets demonstrate HyperGAT’s superiority, with accuracy improvements of 2-4% over existing state-of-the-art methods. The model also significantly reduces memory consumption, making it suitable for large-scale applications. Ablation studies confirm that both attention modules are crucial for performance, validating the importance of high-order semantic modeling.

This work marks a significant step forward in NLP, offering a scalable, expressive framework for understanding complex language structures. Its inductive nature allows for efficient handling of unseen documents, opening avenues for real-time, large-scale text analysis. Future work will explore dynamic hypergraphs and multi-modal data integration, aiming to further enhance the model’s robustness and applicability in diverse scenarios.

Deep Analysis

Background

随着深度学习在自然语言处理中的快速发展,文本分类技术不断演进,从传统的特征工程到深度神经网络模型如CNN和LSTM。这些模型在局部信息捕获方面表现优异,但在建模长距离依赖和复杂语义关系时存在局限。图神经网络(如TextGCN、Graph-CNN)引入后,利用图结构有效捕获词间关系,提升了性能,但多为传导模型,计算成本高,难以扩展。近年来,超图作为高阶关系建模工具,在社交网络和知识图谱中展现潜力,但在文本分类中的应用尚处于起步阶段。本文结合超图结构和注意力机制,突破二阶关系限制,提升高阶语义表达能力,推动自然语言理解的深层次发展。

Core Problem

现有图神经网络在文本分类中的应用,受限于只能建模二阶关系,难以捕获复杂的多词语和主题关系。同时,构建全局文档-词图的高昂计算成本限制了模型的可扩展性和实时性。尤其在大规模、多类别、多主题场景中,传统方法难以满足工业需求。如何在保证表达能力的同时,提升模型效率,成为亟待解决的难题。本文旨在通过超图结构,突破二阶关系限制,增强模型对高阶语义的捕获能力,并设计高效的注意力机制,兼顾性能与成本。

Innovation

核心创新包括:1)引入超图结构,将词作为节点,句子和主题作为超边,突破二阶关系限制,捕获多词语的高阶语义关系;2)设计节点-超边双重注意力机制,动态调整信息权重,增强模型表达能力;3)采用文档级超图,避免全局图构建的高成本,实现端到端训练;4)模型具有良好的迁移性,支持新文档的快速推断。该方法结合超图的高阶关系建模和注意力机制,有效提升文本理解能力。

Methodology

  • �� 构建超图:将词作为节点,句子和主题作为超边,通过滑动窗口和LDA模型生成超边。
  • �� 初始化节点特征:使用预训练词向量(如GloVe)作为节点属性。
  • �� 超图层设计:每层包含节点-超边双重注意力机制,节点通过超边注意力聚合超边信息,超边通过节点注意力聚合节点信息。
  • �� 双重注意力机制:节点注意力计算节点对超边的贡献,超边注意力突出关键超边。
  • �� 多层堆叠:堆叠多层超图层,提取深层次语义特征。
  • �� 文档表示:节点特征池化后,输入分类器(softmax)实现文本分类。

Experiments

采用五个公开数据集(20NG、R8、R52、Ohsumed、MR),比较包括TextGCN、CNN、LSTM等多种基线。模型超参数通过验证集调优,训练100轮,采用早停策略。评估指标为准确率,重复多次取平均。通过消融实验验证节点和超边注意力的重要性。模型在内存和时间方面优于传导模型,验证了其良好的扩展性。不同训练比例的实验显示模型在少量标注数据下仍保持优异性能,确保实用性。

Results

HyperGAT在五个数据集上均优于所有基线,准确率最高达94.98%,比TextGCN(inductive)提升超过4个百分点。模型内存消耗减少70%,实现更大规模应用。消融实验显示,去除节点或超边注意力均降低性能,验证机制有效。在少量训练数据下,HyperGAT表现依然优异,展现强泛化能力。

Applications

该模型适用于大规模文本分类场景,如新闻筛选、内容过滤、情感分析等。只需构建超图,即可实现高阶语义捕获,适合工业中的实时推荐和内容管理。未来结合多模态信息,将提升多源数据理解能力。

Limitations & Outlook

模型依赖预训练主题模型,可能引入偏差。超图在极长文本或噪声多的场景中效率受限。超边数量随文本复杂度增加,需优化超边采样策略。未来将探索动态超图和多模态融合,提升模型鲁棒性和效率。

Plain Language Accessible to non-experts

想象你在一个学校里,每个学生代表一个词,班级代表一句话或一个主题。传统方法就像只让两个学生单独聊天,难以理解整个班级的合作关系。而超图就像让多个学生同时在一个大会议室里讨论,大家都可以一起交流,理解更全面。老师(注意力机制)会特别关注那些最重要的学生或最关键的讨论内容,帮助你更快理解整个班级的想法。这样,学校的合作变得更高效,学习也更深入,就像模型能更好理解文本中的深层含义一样。

ELI14 Explained like you're 14

想象你在学校,有很多学生(词),他们组成不同的小组(句子或主题)。以前的方法就像只让两个学生单独聊天,理解有限。超图就像让多个学生在一个大会议室一起讨论,大家都能同时交流,信息更丰富。老师(注意力机制)会特别关注那些最重要的学生或讨论内容,帮你更快理解整个班级的想法。这让学习变得更快更聪明,就像模型能更准确理解文本内容一样。这样一来,学校和模型都变得更厉害、更高效!

Abstract

Text classification is a critical research topic with broad applications in natural language processing. Recently, graph neural networks (GNNs) have received increasing attention in the research community and demonstrated their promising results on this canonical task. Despite the success, their performance could be largely jeopardized in practice since they are: (1) unable to capture high-order interaction between words; (2) inefficient to handle large datasets and new documents. To address those issues, in this paper, we propose a principled model -- hypergraph attention networks (HyperGAT), which can obtain more expressive power with less computational consumption for text representation learning. Extensive experiments on various benchmark datasets demonstrate the efficacy of the proposed approach on the text classification task.

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