Volunteered Geographic Information Research in the First Decade: Visualizing and Analyzing the Author Connectedness of Selected Journal Articles in GIScience

Abstract

Volunteered geographic information (VGI) has been widely explored by researchers for decision support in various application domains because the data are cost-effective to collect and their richness in volume and spatiotemporal coverage is unrivaled against traditional data sources. This study visualizes and analyzes a network of the authors of selected journal articles in GIScience about the first decade of VGI research. It uses the number of citations, one local network centrality measures (i.e., degree), and three global network centrality measures (i.e., closeness centrality, betweenness centrality, and eigenvector centrality) for quantifying the author importance. A new rule-based weighting method has also been developed for taking into account author sequences when computing the global centrality measures. Results show that the connectedness of the European researchers is strong, and Europe and North America have the highest numbers of prominent VGI researchers. Closeness among researchers does not seem to contribute heavily to the increase in citations. Rather, the number of direct connections in the network, the authors’ control over the network, and the quality of research connections is more important. European and North American authors as a whole play a leading role in the VGI research, but on average (per author influence) are only outstanding in terms of the citation numbers and have relatively more control over the network. Lastly, this study has revealed the relatively more diverse VGI research topics investigated over a longer time span in North America and Europe compared with other regions of the globe, highlighting the major problems that have been studied across the VGI research network.