[data quality]
A measured, observed, calculated, or interpreted value that differs from the true value or the value that would be obtained by a perfect observer using perfect equipment and perfect methods under perfect conditions.
[accuracy]
In a GIS database, a spatial or attribute value that differs from the true value. An error may also be understood as the totality of wrong or unreliable information in a database. A spatial error can be positional (incorrect coordinates) or topological (features do not properly connect, intersect, or adjoin). An attribute error can be the result of incorrect quantities or descriptions or due to missing or invalid values. There are many processes that can potentially introduce errors to a GIS database, for example, as the result of human errors, flawed instruments, map digitizing errors, data integration errors of scale, data collection or conversion errors, and so on.
[Esri software]
In geodatabase topology, violation of a topology rule detected during the validation process.