Evaluating object-based data quality attributes in the Land Cover Map 2000 of the United Kingdom

Standards that have been created for the reporting of data quality in spatial databases focus primarily on database level metadata, which does not address the issue of varying quality within a dataset. This issue may be advanced by the inclusion of metadata at an object level. The Land Cover Map 2000 (LCM2000) is a national database for the UK and contains a large amount of object-based quality metadata, which is reviewed. An analysis of uncertainty in the extent of three land cover types is carried out using a cumulative evidence method, utilizing a number of existing datasets, each purporting to represent the extent of the phenomenon in question. The output of this analysis is compared to the metadata in the LCM2000, in order to assess the usefulness of the metadata in understanding attribute accuracy. Results of this comparison are presented, showing that some of the object-based metadata gives a useful indication as to the certainty of classification