For instance, if we are studying cancer rates among census tracts in a given city local clusters in the rates mean that there are areas that have higher or lower rates than is to be expected by chance alone; that is, the values occurring are above or below those of a random distribution in space.
For instance, if we are studying cancer rates among census tracts in a given city, local clusters indicate that there are areas with higher or lower rates than would be anticipated by chance; essentially, the observed values deviate from those of a random distribution in space.