Interactive visual analysis of geographic data on mobile devices based on dynamic queries

The capabilities of current mobile devices, especially PDAs, are making it possible to design and develop mobile applications that employ visual techniques for using geographic data in the field. These applications can be extremely useful in areas as diverse as tourism, business, natural resources management and homeland security. In this paper, we present a system aimed at supporting users in the exploratory analysis of geographic data on PDAs through a highly interactive interface based on visual dynamic queries. We propose alternative visualizations to display query results and present an experimental evaluation aimed at comparing their effectiveness on a PDA in a tourist scenario. Our findings provide an experimental confirmation of the unsuitability of the typical visualization, employed by classic dynamic query systems, which displays only those results that fully satisfy a query, in those cases where only sub-optimal results are obtainable. For such cases, the results of our study highlight the usefulness of visualizations that display all results and their degree of satisfaction of the query.