Geographic Information Retrieval: Classification, Disambiguation and Modelling

This thesis aims to augment the Geographic Information Retrieval process with information extracted from world knowledge. This aim is approached from three directions: classifying world knowledge, disambiguating placenames and modelling users. Geographic information is becoming ubiquitous across the Internet, with a significant proportion of web documents and web searches containing geographic entities, and the proliferation of Internet enabled mobile devices. Traditional information retrieval treats these geographic entities in the same way as any other textual data. In this thesis I augment the retrieval process with geographic information, and show how methods built upon world knowledge outperform methods based on heuristic rules. The source of world knowledge used in this thesis is Wikipedia. Wikipedia has become a phenomenon of the Internet age and needs little introduction. As a linked corpus of semi-structured data, it is unsurpassed. Two approaches to mining information from Wikipedia are rigorously explored: initially I classify Wikipedia articles into broad categories; this is followed by much finer classification where Wikipedia articles are disambiguated as specific locations. The thesis concludes with the proposal of the Steinberg hypothesis: By analysing a range of wikipedias in different languages I demonstrate that a localised view of the world is ubiquitous and inherently part of human nature. All people perceive closer places as larger and more important than distant ones. The core contributions of this thesis are in the areas of extracting information from Wikipedia, supervised placename disambiguation, and providing a quantitative model for how people view the world. The findings clearly have a direct impact for applications such as geographically aware search engines, but in a broader context documents can be automatically annotated with machine readable meta-data and dialogue enhanced with a model of how people view the world. This will reduce ambiguity and confusion in dialogue between people or computers.