1. In the context of point processes, methods underlying tests of randomness. If locations are positioned randomly in the plane, at a density λ per unit area, then the squared distance from a location to its nearest neighbour will have an exponential distribution with mean 1/(πλ), and the distance to its kth nearest neighbour will have a gamma distribution with mean k/(πλ).

2. In the context of experimental design, methods used to improve estimates of plot yields by using neighbouring values as an indicator of the fertility of a plot of interest.

3. In the context of cluster analysis and discriminant analysis, methods used to determine from which population, of a given set of populations, an observation has arisen.