Categories (nominal)

• differientiate things and uses
  • e.g. municipal zoing map
  • e.g. Sierra Nevada land ownership
    
    
• use text (abbrev.) or numeric codes, which must be identical!
  • data dictionary describes attribute code

• ranks assigned or able to order in some progressive fashion
  • based on assigned classes in attribute table
  • e.g. (streams, class I, II, III, roads, etc.)
    
    
• alike in some way or order
  • e.g. road classes - Freeways, hwys., major roads, minor roads, unpaved, trail
    
    
• often used with color ramp to indicate rank, degree or intensity
• often used to simplify measurements and reveal patterns
  • e.g. population statistics
    
    

• show total numbers (actual tally of map features)
  • e.g. (businesses by number of employees, household incomes, population, etc.)
    
    
• often shows frequency as dots, not areas
  
  

• relationship between two quantities, dividing one into the other
  • evens out (or normalizes) differences between differing areas
    
    
• more accurately shows distribution of phenomenon
  • e.g. (percentage of available parking, etc.)
    
    
• assign functional classification scheme
  • (natural breaks, quantile, equal interval and standard dev. -- discussed later)
    

Summary Matrix of feature types and attribute types

Index