🤖 AI Summary
This work proposes a novel approach to graph classification by replacing the conventional parameterized classifier—such as a linear Softmax layer—in graph neural networks (GNNs) with non-negative kernel regression (NNK). Instead of relying on learnable parameters, the method constructs predictions via convex combinations of embeddings from similar training samples, effectively performing interpolation in the embedding space. This substitution not only enhances model interpretability by grounding predictions in actual training instances but also offers stronger theoretical guarantees for generalization. By eliminating the need for additional trainable parameters in the classification head, the approach provides a transparent and efficient mechanism that maintains predictive performance while improving the explainability and robustness of GNN-based graph classification.
📝 Abstract
Graph Neural Networks (GNNs) have become a standard approach for learning from graph-structured data. However, their reliance on parametric classifiers (most often linear softmax layers) limits interpretability and sometimes hinders generalization. Recent work on interpolation-based methods, particularly Non-Negative Kernel regression (NNK), has demonstrated that predictions can be expressed as convex combinations of similar training examples in the embedding space, yielding both theoretical results and interpretable explanations.