Ad Hoc Determination of Geographic Regions for Concept@Location Queries

Abstract

Textual geographic queries to search engines usually consist of the desired concept and also of one or more terms describing a location, which is often the name of a city, which in turn can usually be grounded with the help of a gazetteer. On other occasions, though, the location refers to a (vague) geographic region and may also be a vernacular expression for that region, so that this location specification cannot be found in a gazetteer.

In this chapter we describe an approach to determine the boundaries for such locations and how to integrate this approach into the query process. The key features of our approach are that a geographic search engine is able to handle any textual description of a geographic region at query time and that this computation can be done completely automatically. In our approach we derive a representation for a region from the toponyms found in the top web documents resulting from a query using the terms describing the location.

In addition to that, we introduce two other uses of this approach: first, this method can be used for answering where-is queries (where only a query location, but no query concept is given), and second, we can determine geographic representations for arbitrary terms that are not genuine geographic regions. In that case, the geographic representation provides a visual impression of the geographic correlation of those terms.