(1) (Data West Research Agency definition: see GIS glossary.) The closeness of results of observations, computations, or estimates of graphic map features to their true value or position. Relative accuracy is a measure of the accuracy of individual features on a map when compared to other features on the same map. Absolute accuracy is a measure of the location of features on a map compared to their true position on the face of the Earth. Mapping accuracy standards generally are stated as acceptable error and the proportion of measured features that must meet the criteria. In the case of some plotting and display devices, accuracy refers to tolerance in the display of graphic features relative to the original coordinate file.