Three sources of Fuzzyness
 
 
- (1) in the classification
- 
- which areas not in Cluster 27 are very similar in their characteristics
 
- (2) in the geographics
- 
- which areas not in Cluster 27 are located nearby those that are
 
- (3) in the interaction between these two primary effects 
- 
- in the context of a specific application