ABSTRACT
Policy decision-making involves the use of geographic data and geographic information systems (GIS) techniques. This chapter highlights research issues to be addressed on data accuracy in GIS. It provides a general framework under which to discuss the research issues in data accuracy. The application of probability theory in the quantification uncertainty is based on the assumption that the representation of a geographic feature in the database is a result of one of multiple realizations of the geographic feature. The uncertainty in the output of a GIS-based analysis contains two parts: one due to the propagation of uncertainty from the input data and the other due to the error in the model on which the analysis is based. The propagation of uncertainty in the input data through GIS-based analyses to the output has received much attention. The chapter provides an overview of the issues related to uncertainty in geographic data and GIS-based analyses from the perspective of geographic data life cycle.
