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  • Publication
    Métadonnées seulement
    Bibliographic database access using free-text and controlled vocabulary: an evaluation
    This paper evaluates and compares the retrieval effectiveness of various search models, based on either automatic text-word indexing or on manually assigned controlled descriptors. Retrieval is from a relatively large collection of bibliographic material written in French. Moreover, for this French collection we evaluate improvements that result from combining automatic and manual indexing. First, when considering various contexts, this study reveals that the combined indexing strategy always obtains the best retrieval performance. Second, when users wish to conduct exhaustive searches with minimal effort, we demonstrate that manually assigned terms are essential. Third, the evaluations presented in this paper study reveal the comparative retrieval performances that result from manual and automatic indexing in a variety of circumstances. (c) 2004 Elsevier Ltd. All rights reserved.
  • Publication
    Métadonnées seulement
    Cross-language information retrieval: experiments based on CLEF 2000 corpora
    Search engines play an essential role in the usability of Internet-based information systems and without them the Web would be much less accessible, and at the very least would develop at a much slower rate. Given that non-English users now tend to make up the majority in this environment, our main objective is to analyze and evaluate the retrieval effectiveness of various indexing and search strategies based on test-collections written in four different languages: English, French, German, and Italian. Our second objective is to describe and evaluate various approaches that might be implemented in order to effectively access document collections written in another language. As a third objective, we will explore the underlying problems involved in searching document collections written in the four different languages, and we will suggest and evaluate different database merging strategies capable of providing the user with a single unique result list. (C) 2002 Published by Elsevier Science Ltd.
  • Publication
    Métadonnées seulement
    Result merging strategies for a current news metasearcher
    (2003)
    Rasolofo, Yves
    ;
    Hawking, David
    ;
    Metasearching of online current news services is a potentially useful Web application of distributed information retrieval techniques. We constructed a realistic current news test collection using the results obtained from 15 current news Web sites (including ABC News, BBC and AllAfrica) in response to 107 topical queries. Results were judged for relevance by independent assessors. Online news services varied considerably both in the usefulness of the results sets they returned and also in the amount of information they provided which could be exploited by a metasearcher. Using the current news test collection we compared a range of different merging methods. We found that a low-cost merging scheme based on a combination of available evidence (title, summary, rank and server usefulness) worked almost as well as merging based on downloading and rescoring the actual news articles. (C) 2002 Elsevier Science Ltd. All rights reserved.