Search (11 results, page 1 of 1)

  • × author_ss:"Robertson, S.E."
  • × type_ss:"a"
  • × year_i:[1990 TO 2000}
  1. Robertson, S.E.; Hancock-Beaulieu, M.M.: On the evaluation of IR systems (1992) 0.02 
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  2. Robertson, S.E.: Overview of the Okapi projects (1997) 0.02 
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    Abstract
    Gives a brief description of the Okapi projects and of the work of the centre for Interactive Systems Research in the Department of Information Science at City University, London,UK, where these projects have been developed. Describes firstly one version of an information retrieval system which contains some of the central features of the Okapi projects, and follows this with an indication of the variety of systems now implemented or implementable within the present setup
    Source
    Journal of documentation. 53(1997) no.1, S.3-7
  3. MacFarlane, A.; Robertson, S.E.; McCann, J.A.: Parallel computing in information retrieval : an updated review (1997) 0.01 
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    Abstract
    Reviews the progress of parallel computing in information retrieval. Stresses the importance of the motivation is using parallel computing for text retrieval. Analyzes parallel IR systems using a classification defined by Rasmussen and describes some parallel IR systems. Gives a description of the retrieval models used in parallel information processing and notes areas where research is needed
    Source
    Journal of documentation. 53(1997) no.3, S.274-315
  4. Robertson, S.E.; Walker, S.; Beaulieu, M.: Laboratory experiments with Okapi : participation in the TREC programme (1997) 0.01 
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    Abstract
    Briefly reviews the history of laboratory testing of information retrieval systems, focusing on the idea of a general purpose test collection of documents, queries and relevance judgements. Gives an overview of the methods used in TREC (Text Retrieval Conference) which is concerned with an ideal test collection, and discusses the Okapi team's participation in TREC. Also discusses some of the issues surrounding the difficult problem of interactive evaluation in TREC. The reconciliation of the requirements of the laboratory context with the concerns of interactive retrieval has a long way to go
    Source
    Journal of documentation. 53(1997) no.1, S.20-34
  5. Robertson, S.E.; Beaulieu, M.: Research and evaluation in information retrieval (1997) 0.01 
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    Abstract
    Offered as a discussion document drawing on the experiences of the Okapi team in developing information retrieval systems. Raises some of the issues currently exercising the information retrieval community in the context of experimentation and evaluation
    Source
    Journal of documentation. 53(1997) no.1, S.51-57
  6. Huang, X.; Robertson, S.E.: Application of probilistic methods to Chinese text retrieval (1997) 0.00 
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    Abstract
    Discusses the use of text retrieval methods based on the probabilistic model with Chinese language material. Since Chinese text has no natural word boundaries, either a dictionary based word segmentation method must be applied to the text, or indexing and searching must be done in terms of single Chinese characters. In either case, it becomes important to have a good way of dealing with phrases or contoguous strings of characters; the probabilistic model does not at present have such a facility. Proposes some ad hoc modifications of the probabilistic weighting function and matching method for this purpose
    Source
    Journal of documentation. 53(1997) no.1, S.74-79
  7. Robertson, S.E.; Walker, S.; Hancock-Beaulieu, M.M.: Large test collection experiments of an operational, interactive system : OKAPI at TREC (1995) 0.00 
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    Abstract
    The Okapi system has been used in a series of experiments on the TREC collections, investiganting probabilistic methods, relevance feedback, and query expansion, and interaction issues. Some new probabilistic models have been developed, resulting in simple weigthing functions that take account of document length and within document and within query term frequency. All have been shown to be beneficial when based on large quantities of relevance data as in the routing task. Interaction issues are much more difficult to evaluate in the TREC framework, and no benefits have yet been demonstrated from feedback based on small numbers of 'relevant' items identified by intermediary searchers
  8. Robertson, S.E.: Query-document symmetry and dual models (1994) 0.00 
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    Abstract
    The idea that there is some natural symmetry between queries and documents is explained. If symmetry can be assumed, then it lead to a conception of 'dual' models in information retrieval (given a model, we can construct a dual model in which the roles of documents and queries are reversed). But symmetry breaks down in various ways, which may invalidate this construction. If we can construct a dual, it is not obvious that it can be combined with the original
    Source
    Journal of documentation. 50(1994) no.3, S.233-238
  9. Robertson, S.E.; Walker, S.; Beaulieu, M.M.; Gatford, M.; Payne, A.: Okapi at TREC-4 (1996) 0.00 
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    Imprint
    Gaithersburgh, MD : National Institute of Standards and Technology
  10. Beaulieu, M.M.; Gatford, M.; Huang, X.; Robertson, S.E.; Walker, S.; Williams, P.: Okapi an TREC-5 (1997) 0.00 
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    Imprint
    Gaithersburgh, MD : National Institute of Standards and Technology
  11. Robertson, S.E.: On term selection for query expansion (1990) 0.00 
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    Abstract
    In the framework of a relevance feedback system, term values or term weights may be used to (a) select new terms for inclusion in a query, and/or (b) weight the terms for retrieval purposes once selected. It has sometimes been assumed that the same weighting formula should be used for both purposes. This paper sketches a quantitative argument which suggests that the two purposes require different weighting formulae
    Source
    Journal of documentation. 46(1990) no.4, S.359-364

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