HG-Meta: Graph Meta-learning over Heterogeneous Graphs

Prevailing supervised graph neural networks suffer from potential performance degradation in the label sparsity case. Though increasing attention has been paid to graph few-shot learning methods for learning effective graph embeddings under the scarcity of labeled data, most existing works study homogeneous graphs while ignoring the ubiquitousness of heterogeneous graphs (HG), where multi-typed nodes are interconnected by multi-typed edges. To this end, we propose to tackle few-shot learning on HG and develop a novel model for Heterogeneous Graph Meta-learning (a.k.a. HG-Meta). Regarding the graph heterogeneity, HG-Meta firstly builds a graph encoder to aggregate heterogeneous neighbors information from multiple semantic contexts (generated by meta-paths). Secondly, to train the graph encoder with meta-learning in a few-shot scenario, HG-Meta tackles meta-task differences produced from meta-task sampling procedure on HG with a task feature scaling module and a degree based task attention module. To further alleviate low-data problem, HG-Meta leverages unlabelled information in HG with auxiliary self-supervised learning task alongside the meta-optimization process to facilitate node embedding. Extensive experiments on two HG datasets demonstrate that HG-Meta outperforms state-of-the-art methods for multiple few-shot node classification tasks.