Centrality is an elusive concept since it depends upon the viewer’s perspective.

One person may consider the “city center” to be the place where the city’s economic activity, busy markets, etc., are located. For a map designer, however, the center represents the exact geographic midpoint of the city (i.e., it could even be your house).

The measure of centrality of a distribution should represent the midpoint of that distribution, but how can that be defined? There are three different perspectives regarding the location of the distribution’s center and there are accordingly three measures of centrality: The mode , the median and the average.