Assessing the quality of repositories of volunteered geographical information

Abstract

In this paper the authors assess two repositories of volunteered geographical information (VGI) (the 2nd South African Bird Atlas Project and OpenStreetMap) against the seven commonly-used dimensions of the quality of geographical information (positional accuracy, thematic accuracy, semantic accuracy, temporal accuracy, completeness, logical consistency and lineage) and in terms of five challenges they identified previously for the quality of VGI (dependence on the purpose and the context in which the data are used, lack of involvement by users in developing standards, anonymous VGI contributions, bias in VGI, and that not all aspects of data quality can be assessed quantitatively). Their research shows that these repositories have procedures in place to check the quality of the data and confirms that it is difficult to assess data quality. This work also contributes towards a new and improved understanding of VGI, its quality and also its usability.