Few-shot node classification poses a significant challenge for Graph Neural Networks (GNNs) due to insufficient supervision and potential distribution shifts between labeled and unlabeled nodes. Self-training has emerged as a widely popular framework to leverage the abundance of unlabeled data, which expands the training set by assigning pseudo-labels to selected unlabeled nodes. Efforts have been made to develop various selection strategies based on confidence, information gain, etc. However, none of these methods takes into account the distribution shift between the training and testing node sets. The pseudo-labeling step may amplify this shift and even introduce new ones, hindering the effectiveness of self-training. Therefore, in this work, we explore the potential of explicitly bridging the distribution shift between the expanded training set and test set during self-training. To this end, we propose a novel Distribution-Consistent Graph Self-Training (DC-GST) framework to identify pseudo-labeled nodes that are both informative and capable of redeeming the distribution discrepancy and formulate it as a differentiable optimization task. A distribution-shift-aware edge predictor is further adopted to augment the graph and increase the model's generalizability in assigning pseudo labels. We evaluate our proposed method on four publicly available benchmark datasets and extensive experiments demonstrate that our framework consistently outperforms state-of-the-art baselines.

提出了一种新颖的分布一致图自训练（DC-GST）框架，通过显式地解决自训练过程中扩展训练集与测试集之间的分布差异，识别既具有信息量又能弥补分布差异的伪标记节点，并通过可微分的优化任务进行建模。采用了考虑分布差异的边预测器来增强图，提高模型在分配伪标签上的泛化能力。在四个公开基准数据集上进行了评估，并广泛实验证明，该框架始终优于最先进的基线模型。

基于分布一致性的稀疏标签图神经网络自训练