UNSW at GeoCLEF 2006

This paper describes our participation in the GeoCLEF monolingual English task of the Cross Language Evaluation Forum 2006. Our retrieval system consists of four modules: the geographic knowledge base; the indexing module; the document retrieval module and the ranking module. The geographic knowledge base provides information about important geographic entities around the world and relationships among them. The indexing module creates and maintains textual and geographic indices for document collections separately. The Boolean model is used in the document retrieval module to retrieve documents that meet both textual and geographic criteria. The ranking module applied ranking functions that are learned using Genetic Programming to the retrieved results. Performance evaluation of the implementation of these system modules is the main objective of this study. The results of our experiments show that the geographic knowledge base, the indexing module and the retrieval module are useful for geographic information retrieval tasks, but the proposed ranking function learning method doesn't work well.