It looks really good question, in particular, related to geological formation units, geomorphology with hydrogeology (drainage basin, etc.)
And it would be nice if ESRI Geostatistical/Spatial team can help answer...
Regards,
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In SAS (& others like S+ or R), the chisq option is used on the tables statement to obtain the test statistic and its associated p-value. And wondering if ArcGIS Geostatistical /spatial statistics will apply this chisq function onto categorical geoscience layers.
Really eager to get some deep insights on some statistics functions/algorithms on GIS layers (2 or more) to practically support many applications within ArcGIS, especially, over surface layers TIN/DEM for some analysis scenarios ...