Guest Editors’ Introduction 20 July/August 2006 Published by the IEEE Computer Society 0272-1716/06/$20.00 © 2006 IEEE W elcome to this theme issue on explor- ing geovisualization. Here, we focus on some of the methods, processes, and collaborations involved with visualizing geographic information and geospatial data. The authors present approaches that encompass information and scientific visualization techniques as well as methods developed in cartogra- phy and geographic information science. For more than two decades, the cartographic, geographic information system (GIS), and visualization communities have worked in closely related yet arguably independent disciplines. In this theme issue, we focus on the cross- disciplinary connections that facilitate the visual dis- play and interactive exploration of geospatial data and the information derived from it. Our efforts are the result of a decade’s worth of col- laboration among the ■ ACM Siggraph Carto Project (http://www.siggraph. org/~rhyne/carto/), ■ International Cartographic Association’s Commission on Visualization and Virtual Environments (http:// www.kartografie.nl/icavis/), and ■ Web3D Consortium’s X3D GeoSpatial Working Group (http://www.web3d.org/x3d/workgroups/ geospatial/). Since the ACM Siggraph Carto Project began in 1996, birds-of-a-feather (BOF) sessions at the annual Siggraph conference have brought these groups together. In that time frame, the Web3D Consortium released GeoVRML Open Source Code (http://www.geovrml.org/1.1/ doc/) that is now modified and included in the X3D standard while the ICA Commission on Visualization and Virtual Reality released a research agenda for geovisualization (http://www.kartografie.nl/icavis/ agenda/index.html). The ACM Siggraph Carto BOF ses- sions have also featured emerging technologies that resulted in applications like Google Earth (http://earth. google.com/) and similar Web-based services. Building on the past work, in spring 2005, we issued a call for contributions to this issue on geovisualization. We received 40 inquiries about submission and at the submission deadline had 22 completed papers. For each submission, we assigned two reviewers: one from the computer graphics/visualization community and anoth- er from the cartography/geographic information sys- tems community. We also provided our own editorial comments and suggestions. The reviews and our edi- torial commentaries were completed in mid-November 2005. We accepted five papers and recommended revi- sions and other publication venues for many of the other papers. This review process was demanding and we are appreciative to the 40 or so academic colleagues who participated. We are thrilled to present five articles that are indicative of the broad range of applications and future directions in geovisualization. In the first article, “MapShaper.org: A Map General- ization Web Service,” Harrower and Bloch discuss the development of an online map generalization applica- tion constructed in Macromedia Flash and available remotely through a Web browser. In cartography, the practice of generalization involves conceptualizing important features and employing graphic symbols to synthesize salient information on a map. Harrower and Bloch present an interactive tool for automatically addressing generalization problems for on-demand mapping services. The second article presents GIS science perspectives on developing 3D Web-based visualization tools. “Web- Based Visualization of 3D Geospatial Data Using Java3D” by Hobona, James, and Fairbairn describes a prototype system for integrating varied database servers with 3D spatial data visualization techniques. Their Geospatial Database Online Visualization Environment (GeoDOVE) supports mappings between the Open Geospatial Consortium Simple Features geometry and Java3D geometry structures. In “The Distance-Similarity Metaphor in Region-Dis- play Spatializations,” Fabrikant, Montello, and Mark report on two experiments they conducted on people’s ability to interpret region-based spatializations or map-like displays of nongeographic information. This investigation addresses color-hue effects and treemap elements. The authors’ evaluative research offers exper- imental evidence to support the appropriate use of tra- ditional cartographic design principles in information visualization problems. Forsberg et al.’s article, “Adviser: Immersive Field Work for Planetary Scientists,” introduces five case stud- Theresa-Marie Rhyne North Carolina State University Alan MacEachren Pennsylvania State University Jason Dykes City University London Exploring Geovisualization