• Calendar

June 30, Wednesday
13:00 – 14:00

The popularity of web-based mapping services such as Google Earth/Maps and Microsoft Virtual Earth (Bing), has led to an increasing awareness of the importance of spatial data and its incorporation into both web-based search and the databases that support it, whereas in the past attention to spatial data had been primarily limited to geographic information systems (GIS). An immediate byproduct of this awareness is the expectation of a real time response as is the experience of users of spreadsheets. Spatial data is distinguished from conventional data by having extent, which means that rather than being limited to locations, it also includes collections of locations [and, most importantly in both cases, their attributes]. Having extent is challenging in several respects. First, it is not easy to order such data which impacts the ability to retrieve it quickly. Second, the specification of the data is both vague and ambiguous by virtue of the amount of precision that is needed to make it useful. The ambiguity is very clear when one considers that a location as well as a collection of locations can be specified either or both geometrically via, for example, its centroid or its boundary, and verbally via the name that is used to refer to it. The latter is both aided and complicated by the possible need to make use of knowledge, whether implicit or explicit, of the information that is inherent in its container hierarchy. In this lecture we explore how these issues are manifested and resolved, both conceptually, and via demonstrations of real systems, thereby demonstrating how wide a net has been cast on geographic information systems by todaysapplications.

*The lecture is sponsored by the ACM Distinguished Speaker Program*