Centrality Indices

Abstract

Centrality indices quantify the importance of a node in a given network, which is often identified with the importance of the corresponding entity in the complex system modeled by the network. As the perceived importance is dependent on the kind of network to be analyzed, different centrality indices have been proposed over the years. This chapter gives a short overview of the most important centrality indices, a characterization of centrality indices based on graph-theory, visualization of centrality indices, and some general schemes of how centrality indices are used to analyze networks with selected examples. The main insight of the chapter is that it is necessary to carefully match a centrality index with the research question of interest to enable a meaningful interpretation of the index' results.