Simplifying Hypergraph Neural Networks

Hypergraphs are crucial for modeling higher-order interactions in real-world data. Hypergraph neural networks (HNNs) effectively utilise these structures by message passing to generate informative node features for various downstream tasks like node classification. However, the message passing block in existing HNNs typically requires a computationally intensive training process, which limits their practical use. To tackle this challenge, we propose an alternative approach by decoupling the usage of the hypergraph structural information from the model training stage. The proposed model, simplified hypergraph neural network (SHNN), contains a training-free message-passing block that can be precomputed before the training of SHNN, thereby reducing the computational burden. We theoretically support the efficiency and effectiveness of SHNN by showing that: 1) It is more training-efficient compared to existing HNNs; 2) It utilises as much information as existing HNNs for node feature generation; and 3) It is robust against the oversmoothing issue while using long-range interactions. Experiments based on six real-world hypergraph benchmarks in node classification and hyperlink prediction present that, compared to state-of-the-art HNNs, SHNN shows both competitive performance and superior training efficiency. Specifically, on Cora-CA, SHNN achieves the highest node classification accuracy with just 2% training time of the best baseline.