self-dissimilarity

Self-dissimilarity is a measure of complexity defined in a series of papers by David Wolpert and William G. Macready.{{cite book|title=International Conference on Complex Systems|year=2004|editor=Y. Bar-Yam|publisher=Perseus books, in press|chapter=Self-dissimilarity as a high dimensional complexity measure|first1=David H. |last1=Wolpert|first2=William|last2=Macready|url=http://ti.arc.nasa.gov/m/pub-archive/935h/0935%20(Wolpert).pdf}}{{cite book|author1=Wolpert, D.H. |author2=Macready, W.G. |name-list-style=amp |chapter=Self-Dissimilarity: An Empirically Observable Measure of Complexity|title=Unifying Themes in Complex Systems|editor=Y. Bar-Yam|publisher=Perseus books|year=2000|url=http://ti.arc.nasa.gov/m/profile/dhw/papers/84.pdf}}

The degrees of self-dissimilarity between the patterns of a system observed at various scales (e.g. the average matter density of a physical body for volumes at different orders of magnitude) constitute a complexity "signature" of that system.