autocorrelation

A measure of the degree to which attribute values in a data set are related to one another over space. If locations near one another tend to have similar values, the data set is positively autocorrelated. If locations near one another tend to be different (a 'checkerboard' effect), the data set is negatively autocorrelated. Where there is no particular spatial pattern to the data there is no autocorrelation. See also spatial dependence.