Geographic Information Systems

datum Basis for measurement of position on the Earth’s surface. discrete object view Conceptualization of geographic phenomena as analogous to a tabletop littered with countable, possibly movable objects. ecological fallacy The fallacy of making inferences about individuals from aggregated data. field view Conceptualization of geographic phenomena as a set of functions over geographic space. geocoding Conversion of addresses, place names, or other geographic references to coordinates, such as latitude and longitude. modifiable areal unit problem The dependence of analysis of aggregate data on the precise reporting zones used for aggregation. polyline Representation of a line as a sequence of points connected by straight segments. spatial analysis A method of analysis whose results depend on the locations of the objects being analyzed. street centerline data set Representation of a street network as a collection of lines approximately centered along each street.