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Computer Engineering ›› 2023, Vol. 49 ›› Issue (1): 57-64,72. doi: 10.19678/j.issn.1000-3428.0063646

• Artificial Intelligence and Pattern Recognition • Previous Articles     Next Articles

Recommendation Method for MOOC Based on Graph Contrastive Learning

WANG Shuyan, GUO Ruihan, SUN Jiaze   

  1. School of Computer Science and Technology, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
  • Received:2021-12-28 Revised:2022-02-15 Published:2022-03-22

基于图对比学习的MOOC推荐方法

王曙燕, 郭睿涵, 孙家泽   

  1. 西安邮电大学 计算机学院, 西安 710121
  • 作者简介:王曙燕(1964-),女,二级教授、博士,主研方向为软件测试、数据挖掘、智能信息处理;郭睿涵,硕士研究生;孙家泽,教授、博士。
  • 基金资助:
    陕西省重点研发计划项目(2020GY-010);陕西省教改重点攻关项目(21BG038)。

Abstract: With the rapid development of MOOC education platforms, the number of courses and users have increased sharply, and learners often have no way to start when studying a wide variety of courses.The application of traditional recommendation methods in MOOC recommendation has a poor recommendation effect for courses with low exposure times and insufficient robustness to noise data. A MOOC recommendation method based on graph contrastive learning is proposed to provide high-quality recommendations to learners, and a new data enhancement method is designed for the bipartite graph structure.First, data enhancement is conducted on randomly added or deleted edges of the bipartite graph of user-item interaction, and two subviews are obtained.Next, the graph convolution neural network is used to extract the node features of the original bipartite graph and two subviews, obtain the node representation of users and projects, and construct the auxiliary tasks of recommendation supervision task and contrastive learning for joint optimization. Finally, the node representations of users and projects are dot products to obtain the recommendation results.A top-K recommendation is conducted on the MOOC dataset.The experimental results show that the proposed method is better than the lightgcn model.Recall@5 and NDCG@5 are significantly improved:Recall@5 by up to 7.8% and NDCG@5 by up to 7.3%.This study demonstrates that the proposed method can effectively improve the recommendation accuracy of the model for courses with low exposure times and robustness to noise data.

Key words: MOOC recommendation, Graph Convolution Network(GCN), self-supervised learning, personalized recommendation, graph contrastive learning

摘要: 随着MOOC在线教育平台的飞速发展,课程和用户数量激增,学习者在面对种类繁多的课程时往往较难选择,传统的推荐方法在MOOC课程推荐中应用存在对曝光次数较低的课程推荐效果差和对噪声数据鲁棒性不足的问题。为给学习者提供高质量的推荐,提出一种图对比学习的MOOC推荐方法,同时针对二分图结构给出一种新的数据增强方法。对输入的用户项目交互的二分图随机添加或者删除边进行数据增强,得到两个子视图,使用图卷积神经网络对原始二分图和两个子视图进行节点特征提取得到用户和项目的节点表征,并构建推荐监督任务和对比学习的辅助任务进行联合优化,在此基础上将用户和项目的节点表征进行点积获得推荐结果。在MOOC数据集上进行Top-K推荐的实验结果表明,相较于LightGCN模型,该方法在Recall@5和NDCG@5上均有显著提升,最高分别提升7.8%和7.3%,能够有效提高模型对于曝光次数较低的课程的推荐准确性和对于噪声数据的鲁棒性。

关键词: MOOC推荐, 图卷积网络, 自监督学习, 个性化推荐, 图对比学习

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