2019

PairNorm: Tackling Oversmoothing in GNNs

Zhao, Lingxiao, Akoglu, Leman

Understand

The performance of graph neural nets (GNNs) is known to gradually decrease with increasing number of layers.

  • This decay is partly attributed to oversmoothing, where repeated graph convolutions eventually make node embeddings indistinguishable.
  • We take a closer look at two different interpretations, aiming to quantify oversmoothing.
  • Our main contribution is PairNorm, a novel normalization layer that is based on a careful analysis of the graph convolution operator, which prevents all node embeddings from becoming too similar.

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