Silva, Mário Jorge Gaspar daMartins, Bruno2009-02-062014-11-142009-02-062014-11-142009-03http://hdl.handle.net/10451/14301http://repositorio.ul.pt/handle/10455/2863Text mining and search have become important research areas over the past few years, mostly due to the large popularity of the Web. A natural extension for these technologies is the development of methods for exploring the geographic context of Web information. Human information needs often present specific geographic constraints. Many Web documents also refer to speci c locations. However, relatively little e ort has been spent on developing the facilities required for geographic access to unstructured textual information. Geographically aware text mining and search remain relatively unexplored. This thesis addresses this new area, arguing that Web text mining can be applied to extract geographic context information, and that this information can be explored for information retrieval. Fundamental questions investigated include handling geographic references in text, assigning geographic scopes to the documents, and building retrieval applications that handle/use geographic scopes. The thesis presents appropriate solutions for each of these challenges, together with a comprehensive evaluation of their efectiveness. By investigating these questions, the thesis presents several findings on how the geographic context can be efectively handled by text processing tools.engGeographic Information RetrievalWeb/Text Miningmaster thesis