Unsupervised Graph Domain Adaptation (UGDA) has emerged as a practical solution to transfer knowledge from a label-rich source graph to a completely unlabelled target graph. However, most methods require a labelled source graph to provide supervision signals, which might not be accessible in the real-world settings due to regulations and privacy concerns. In this paper, we explore the scenario of source-free unsupervised graph domain adaptation, which tries to address the domain adaptation problem without accessing the labelled source graph. Specifically, we present a novel paradigm called GraphCTA, which performs model adaptation and graph adaptation collaboratively through a series of procedures: (1) conduct model adaptation based on node's neighborhood predictions in target graph considering both local and global information; (2) perform graph adaptation by updating graph structure and node attributes via neighborhood contrastive learning; and (3) the updated graph serves as an input to facilitate the subsequent iteration of model adaptation, thereby establishing a collaborative loop between model adaptation and graph adaptation. Comprehensive experiments are conducted on various public datasets. The experimental results demonstrate that our proposed model outperforms recent source-free baselines by large margins.

我们提出了一种名为GraphCTA的新范式，通过一系列步骤：在考虑本地和全局信息的情况下，基于目标图中节点邻居的预测进行模型适应；通过邻域对比学习来更新图结构和节点属性进行图适应；以及使用更新后的图作为输入来促进后续模型适应的迭代，从而在没有访问标记源图的情况下解决领域适应问题。我们在各种公共数据集上进行了全面的实验，实验结果表明我们提出的模型较最近的无源基准模型有很大的改进。

合作自适应：无源图领域自适应的双向适应