A spatial distribution with no pattern is called "random", e.g. the arrangement in (a), below.

There are many words used in ecology to describe alternatives to randomness. The terms:
aggregated, patchy, contagious, clustered and clumped all refer to patterns arising from
positive or attractive interactions between individuals in point-referenced data, such as those in (b), below.



Conversely, the terms, inhibited, uniform, regular, even and homogenous refer to patterns
arising from negative or repulsive interactions between individuals, like those in (c), above.

(Note that the term ‘overdispersion’ has been used very confusingly in the past - by statisticians to indicate excess variability or heterogeneity, and by ecologists to indicate regularity of distribution; these meanings are almost opposites of each other).

Sometimes, the elements of the spatial pattern itself may be directional, as in (d), above.
This is termed anisotropy.

Other terms, such as autocorrelated, structured and spatially dependent, are common in related disciplines such as geostatistics, that adopt a different approach than that used in SADIE.