Geographic reference analysis for geographic document querying

Abstract

The work presented in this paper concerns Information Retrieval from geographical documents, i.e. documents with a major geographic component. The final aim, in response to an informational query of the user, is to return a ranked list of relevant passages in selected documents, allowing text browsing within them. We consider in this paper the spatial component of the texts and the queries. The idea is to perform an off-line linguistic analysis of the document, extracting spatial expressions (i.e. expressions denoting geographical localisations). The point is that such expressions are (in general) much more complex than simple place names. We present a linguistic analyser which recognises them, performing a semantic analysis and computing symbolic representations of their "content". These representations, stored in the text thanks to XML annotation, will act as indexes of passages with which queries are compared. The matching of queries with text expressions is a complex process, needing several kinds of numeric and symbolic computations. A prospective outline of it is described.