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Exploring the Lineage of Volunteered Geographic Information with Heat Maps

The term heat maps has only recently started to be used in the context of digital cartography, with the advent of map mash-ups. In this paper, we introduce an approach that uses heat maps to explore the history of OpenStreetMap (OSM). This collection of Volunteered Geographic Information (VGI) [4] has summed up to a massive dataset over the past years ( 170GB of uncompressed XML for the world dataset with its full history). In order to learn about editing, co-editing, and tagging patterns that evolve with the growing dataset (and community), visual exploration tools are required that point the user to features that stand out from its vicinity. In our visual exploration prototype outlined in this paper, we use the number of edits on each OSM feature as the attribute that determines its “heat” in the visualization. We provide further tools to explore the thematic and temporal characteristics of single features identified using the heat map. Our approach allows users and researchers interested in the interaction patterns behind the OpenStreetMap data to easily explore the dataset, without requiring detailed technical knowledge of OSM. The remainder of this paper is organized as follows: In the following section, we point to related work on heat maps and clarify the concept. Section 3 describes the visualization prototype and the technical background, followed by concluding remarks in Section 4.