Semantic expansion of geographic web queries based on natural language positioning expressions

Abstract

The need for better Web search tools is getting increasing attention nowadays. About 20% of the queries currently submitted to search engines include geographic references. Thus, it is particularly important to work with the semantics of such queries, both by understanding the terminology and by recognizing geographic references in natural language text. In this paper, we explore the use of natural language expressions, which we call positioning expressions, to perform geographic searches on the Web, without resorting to geocoded data or gazetteers. Such positioning expressions denote the location of a subject of interest with respect to a landmark. Our approach leads to a query expansion technique that can be explored by virtually any keyword-based search engine. Results obtained in our experiments show an expressive improvement over the traditional keyword-based search and a potential path for tackling many kinds of common geographic queries. © 2007 The Authors. Journal compilation © 2007 Blackwell Publishing Ltd.