Abstract

Users often enter a local expression to constrain a web search to ageographical place. Current search engines’ capability to deal with expressionssuch as “close to” is, however, limited. This paper presents an approach thatuses topological background knowledge to rewrite queries containing localexpressions in a format better suited to standard search engines. To formalizelocal expressions, the Region Connection Calculus (RCC) is extended byadditional relations, which are related to existing ones by means of compositionrules. The approach is applied to web searches for communities in a part ofSwitzerland which are “close to” a reference place. Results show that queryrewriting significantly improves recall of the searches. When dealing withapprox. 30,000 role assertions, the time required to rewrite queries is in therange of a few seconds. Ways of dealing with a possible decrease ofperformance when operating on a larger knowledge base are discussed.