Assessing VGI Data Quality

Abstract

Uncertainty over the data quality of Volunteered Geographic Information (VGI) is the largest barrier to the use of this data source by National Mapping Agencies (NMAs) and other government bodies. A considerable body of literature exists that has examined the quality of VGI as well as proposed methods for quality assessment. The purpose of this chapter is to review current data quality indicators for geographic information as part of the ISO 19157 (2013) standard and how these have been used to evaluate the data quality of VGI in the past. These indicators include positional, thematic and temporal accuracy, completeness, logical consistency and usability. Additional indicators that have 138 Mapping and the Citizen Sensor been proposed for VGI are then presented and discussed. In the final section of the chapter, the idea of integrated indicators and workflows of quality assurance that combine many assessment methods into a filtering system is highlighted as one way forward to improve confidence in VGI.

VGI in National Mapping Agencies: Experiences and Recommendations

“…Even though this type of data needs the development of new and different procedures for collection (see Chapter 10 by Minghini et al, 2017) or quality assessment (see Chapter 7 by Fonte et al, 2017) to become of major interest, VGI is nevertheless a valuable source of data, as it may help NMAs to provide data that are more up-to-date as well as to collect new, additional data that better address user needs. New features usually not collected by NMAs, either due to cost restrictions or because they represent non-traditional topographic data, could be of value to citizens and to various public services and government agencies.…”

The Future of VGI

“…Although VGI has been a growing phenomenon for over a decade now (Capineri et al, 2016;See et al, 2016), one of the major factors that hinders the more widespread diffusion and uptake of VGI is the lack of a robust and standardised way to evaluate data quality, as outlined in Chapter 7 by Fonte et al (2017). VGI could both facilitate and accelerate the transition to Smart Cities and Digital Earth if it were credible enough to trust and hence use in applications that require accurate GI.…”

“…Haklay et al, 2010;Bégin et al, 2013;Antoniou and Skopeliti, 2015;Foody et al, 2015;Senaratne et al, 2016;Fonte et al, 2017), and research on this topic will continue in the future, not least because improving the methods for reporting quality could end up becoming a catalyst for the widespread diffusion of VGI in mainstream geomatics engineering. Well established methods for spatial data quality evaluation (e.g.…”

“…Well established methods for spatial data quality evaluation (e.g. ISO specifications), while still valid, need to be supplemented with additional evaluation tools that take the specific nature of VGI into account (Antoniou and Skopeliti, 2015;Fonte et al, 2017). If adequate quality assurance tools and algorithms fail to materialise, then the future uses of VGI might not expand much beyond what we see today.…”

Integrating Spatial Data Infrastructures (SDIs) with Volunteered Geographic Information (VGI) for creating a Global GIS platform

“…The issue of how to accommodate the diversified, dynamic and easy-to-access VGI data types to SDI is not a serious problem in technical terms; the problem is to define and apply minimum data requirements for VGI that are reasonable and achievable in order to satisfy data quality requirements (Wiemann and Bernard, 2014). Aspects of data quality such as positional accuracy, classification correctness and accuracy of the time measurement may follow the ISO 19157 standard (ISO, 2013; see Chapter 7 by Fonte et al (2017) for more information on quality); a legally binding aspect is that of the topological consistency of the network data. VGI data quality and credibility vary from contributor to contributor (Flanagin and Metzger, 2008;Goodchild and Li, 2012;Foody et al, 2013); thus it is only up to a data provider whether they will respect data quality recommendations and whether they will report on recommendations in the metadata.…”