The PageRank Algorithm

The PageRank algorithm, famously created by Google, is an interesting extension of the Katz centrality. It’s considered a generalization of the Katz centrality to overcome one of its downsides.

The problem with Katz centrality

Let’s think about an example. We have a high-importance node in a network with a relatively high Katz centrality. This node has out-edges going to 10 other nodes. In that same graph, we have another important node with the same Katz centrality as the previous one, but this node only has two out-edges.

If we remember the equation of the Katz centrality, it’s defined as: