SEE: A spatial exploration environment based on a direct-manipulation paradigm

The need for providing effective tools for analyzing and querying spatial d ata is becoming increasingly important with the explosion of data in applic ations such as geographic information systems, image databases, CAD, and re mote sensing. The SEE (Spatial Exploration Environment) is the first effort at applying direct-manipulation visual information seeking (VIS) technique s to spatial data analysis by visually querying as well as browsing spatial data and reviewing the visual results for trend analysis. The SEE system i ncorporates a visual query language (SVIQUEL) that allows users to specify the relative spatial position (both topology and direction) between objects using direct manipulation. The quantitative SVIQUEL sliders (S-sliders) ar e complemented by the qualitative Active-Picture-for-Querying (APIQ) interf ace that allows the user to specify qualitative relative position queries. APIQ provides qualitative visual representations of the quantitative query specified by the S-sliders. This increases the utility of the system for sp atial browsing and spatial trend discovery with no particular query in mind . The SVIQUEL queries are processed using a k-Bucket index structure specif ically tuned for incremental processing of the multidimensional range queri es that represent the class of queries that can be expressed by SVIQUEL. We have also designed a tightly integrated map visualization that helps to pr eserve the spatial context and a bar visualization that provides a qualitat ive abstraction of aggregates and enables the user to visualize the results of the spatial query as well as the nonspatial attributes of the underlyin g spatial objects. The SEE system has been fully implemented as an applet u sing JDK1.1.4. Finally, we compare the spatial exploration environment (SEE ) technology with alternative spatial query environments with respect to it s querying power and the ease of querying.