Abstract. This paper reports the participation of the University of Lisbon at the 2007 GeoCLEF task. We adopted a novel approach for GIR, focused on handling geographic features and feature types on both queries and documents, generating signatures with multiple geographic concepts as a scope of interest. We experimented new query expansion and text mining strategies, relevance feedback approaches and ranking metrics.

The web was invented to quickly exchange data between scientists, but it became a crucial communication tool to connect the world. However, the web is extremely ephemeral. Most of the information published online becomes quickly unavailable and is lost forever. There are several initiatives worldwide that struggle to archive information from the web before it vanishes. However, search mechanisms to access this information are still limited and do not satisfy their users who demand performance similar to live-web search engines.This demo presents the Portuguese Web Archive, which enables search over 1.2 billion files archived from 1996 to 2012. It is the largest full-text searchable web archive publicly available [17]. The software developed to support this service is also publicly available as a free open source project at Google Code, so that it can be reused and enhanced by other web archivists. A short video about the Portuguese Web Archive is available at vimeo.com/59507267. The service can be tried live at archive.pt.

Web information is ephemeral. Several organizations around the world are struggling to archive information from the web before it vanishes. However, users demand efficient and effective search mechanisms to access the already vast collections of historical information held by web archives. The Portuguese Web Archive is the largest full-text searchable web archive publicly available. It supports search over 1.2 billion files archived from the web since 1996. This study contributes with an overview of the lessons learned while developing the Portuguese Web Archive, focusing on web data acquisition, ranking search results and user interface design. The developed software is freely available as an open source project. We believe that sharing our experience obtained while developing and operating a running service will enable other organizations to start or improve their web archives.