National Center for Geographic Information and Analysis

This unit concludes the module on coordinate systems and geocoding. Several important practical issues are raised here that will be important particularly for those who will be working with economic and demographic databases. The difference between continuous and discrete georeferencing is described before focusing on five of the most common methods of discrete georeferencing: address matching, postal code systems, the US Public Land Survey System, the GEOLOC grid and census systems. Examples illustrate each, and the unit concludes with a discussion of issues associated with discrete georeferencing.