Mosaic design in the discipline of permaculture refers to the use of spatial distribution of beneficial assemblies of plants and animals (guilds) to martial two powerful interactive strategies : edge harmonics & species compatibility. Many small areas of difference are created where a few mistakes occur but on average benefits result.
[ after B Mollison, Permaculture, A Designer's Manual, 1988]
This description of landscape development practice strikes me as applicable to other forms of community development, a connecting feature between fractal math (making use of roughness or variability) and learning theory. I see this as useful in developing patterns for Community Learning System Development.