End Notes Current approaches to estimate data commonly use the GPW data, and these have the potential to be adapted to Worldmapper's requirements. Revised gridded cartograms offer great potential to enhance the variety of Worldmapper's visualization capabilities. A different view of the "real" location of the depicted topic can present a better understanding of human action and human patterns on the globe. However, distortions associated with the gridded method are a disadvantage and undermine the purpose of Newman and Gastner's algorithm to preserve the familiar shapes of countries. The potential of the gridded approach and the desire to preserve the familiar shapes must therefore be carefully balanced. Nevertheless, much potential lies in adding more user interactivity and detail to Worldmapper. Grid-based cartograms have the advantage of allowing a user to zoom in to view national and regional details, within a global context. As one of the authors, Danny Dorling, has commented, "Our maps could be made more interactive, certainly, and there are probably many other features that could be added." GIS technology is a key tool to make this happen. A GIS environment not only facilitates data conversion and calculation of cartograms but also allows different geographic scales to be brought together under one map. An easy transfer to popular digital globes can thus be realized, allowing viewers to identify the regional dimension of a subject. Separate regional editions of gridded population cartograms can be generated to visualize the regional variation of population distribution. For additional information, contact Benjamin D. Henning Sheffield S10 2TN United Kingdom Tel.: +44 114 222 7900 Fax: +44 114 279 7912 E-mail: b.henning@sheffield.ac.uk) Related Web sites: www.worldmapper.org and http://www.sasi.group.shef.ac.uk/ 300,000 Esri Customers are within your reach. Advertise today! Maximum Exposure. Minimum Investment. Acknowledgments The authors thank the Leverhulme Trust for funding the Worldmapper project. The trust played no role in the submission or preparation of this work. For Rates and Media Kit, visit www.esri.com/arcuser or e-mail us at ads@esri.com. References Dorling, Danny (2007), "Worldmapper: The Human Anatomy of a Small Planet," PLoS Medicine 4(1), 13–18. Dorling, Danny, Anna Barford, and Mark Newman (2006), "Worldmapper: The World as You've Never Seen It Before," IEEE Transactions on Visualization and Computer Graphics, 12(5), 757–764, doi:10.1109/ TVCG.2006.202. Gastner, M. T., and M. E. J. Newman (2004), "Diffusion-Based Method for Producing Density Equalizing Maps," Proc. Natl. Acad. Sci. USA 101, 7499–7504. Gaffin, S. R. et al. (2004), "Downscaling and Geo-spatial Gridding of Socio-economic Projections from the IPCC Special Report on Emissions Scenarios (SRES)," Global Environmental Change 14(2), 105–123. Hay, S. I., A. Graham, and D. J. Rogers (2006), Global Mapping of Infectious Diseases: Methods, Examples and Emerging Applications, Academic Press, London. Webb, Richard (2006), "Cartography: A Popular Perspective," Nature 439, 800. www.esri.com ArcUser Winter 2010 69