Associating attribute

Attributes may be automatically associated with features that have unique identifiers (Figure below). In the case of vector data, attributes are assigned directly to the features, while in a raster the attributes are assigned to all cells that represent a feature.

It follows that, depending on the data type, assessment of attribute accuracy may range from a simple check on the labelling of features - for example, is a road classified as a metalled road actually surfaced or not? - to complex statistical procedures for assessing the accuracy of numerical data, such as the percentage of pollutants present in a soil.