There are two components to positional accuracy. These are relative and absolute accuracy. Relative accuracy concerns the positioning of map features relative to one another. Often relative accuracy is of greater concern than absolute accuracy. For example, most GIS users can live with the fact that their survey township coordinates do not coincide exactly with the survey fabric, however, the absence of one or two parcels from a tax map can have immediate and costly consequences.
Attribute accuracy is equally as important as positional accuracy.
It also reflects estimates of the truth. Interpreting and depicting boundaries and characteristics for forest stands or soil polygons can be exceedingly difficult and subjective. Most resource specialists will attest to this fact. Accordingly, the degree of homogeneity found within such mapped boundaries is not nearly as high in reality as it would appear to be on most maps. Quality Quality can simply be defined as the fitness for use for a specific data set .