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  • × author_ss:"Robertson, S.E."
  1. Robertson, S.E.: OKAPI at TREC (1994) 0.02 
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    Abstract
    Paper presented at the Text Retrieval Conference (TREC), Washington, DC, Nov 1992. Describes the OKAPI experimental text information retrieval system in terms of its design principles: the use of simple, robust and easy to use techniques which use best match searching and avoid Boolean logic
  2. Robertson, S.E.: Overview of the Okapi projects (1997) 0.01 
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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
    Footnote
    Contribution to a thematic issue on Okapi and information retrieval research
  3. Robertson, S.E.: OKAPI at TREC-1 (1994) 0.01 
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    Abstract
    Describes the work carried out on the TREC-2 project following the results of the TREC-1 project. Experiments were conducted on the OKAPI experimental text information retrieval system which investigated a number of alternative probabilistic term weighting functions in place of the 'standard' Robertson Sparck Jones weighting functions used in TREC-1
  4. Robertson, S.E.: OKAPI at TREC-3 (1995) 0.01 
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    Abstract
    Reports text information retrieval experiments performed as part of the 3 rd round of Text Retrieval Conferences (TREC) using the Okapi online catalogue system at City University, UK. The emphasis in TREC-3 was: further refinement of term weighting functions; an investigation of run time passage determination and searching; expansion of ad hoc queries by terms extracted from the top documents retrieved by a trial search; new methods for choosing query expansion terms after relevance feedback, now split into methods of ranking terms prior to selection and subsequent selection procedures; and the development of a user interface procedure within the new TREC interactive search framework
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  5. Robertson, S.E.: ¬The methodology of information retrieval experiment (1981) 0.01 
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    Source
    Information retrieval experiment. Ed.: K. Sparck Jones
  6. Robertson, S.E.; Walker, S.; Hancock-Beaulieu, M.M.: Large test collection experiments of an operational, interactive system : OKAPI at TREC (1995) 0.01 
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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
    Source
    Information processing and management. 31(1995) no.3, S.345-360
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  7. 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
    Footnote
    Contribution to a thematic issue on Okapi and information retrieval research
  8. 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
  9. Robertson, S.E.: On term selection for query expansion (1990) 0.01 
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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
    Theme
    Semantisches Umfeld in Indexierung u. Retrieval
  10. Bovey, J.D.; Robertson, S.E.: ¬An algorithm for weighted searching on a Boolean system (1984) 0.01 
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    Source
    Information technology: research and development. 3(1984) no.1, S.84-87
  11. Robertson, S.E.: Some recent theories and models in information retrieval (1980) 0.01 
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    Source
    Theory and application of information research. Proc. of the 2nd Int. Research Forum on Information Science, 3.-6.8.1977, Copenhagen. Ed.: O. Harbo u. L. Kajberg
  12. Robertson, S.E.: ¬The parametric description of retrieval tests : Part I: The basic parameters (1969) 0.01 
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    Abstract
    Some parameters and techniques in use for describing the results of test on IR system are analysed. Several considerations outside the scope of the usual 2X2 table are relevant to the choice of parameters. In particular, a variable which produces a 'performance curve' of a system corresponds to an extension of the 2x2 table. Also, the statistical relationships between parameters are all-important. It is considered that precision is not such a useful measure of performance (in conjunction with recall)as fallout. A more powerful alternative to Cleverdon's 'invitable inverse relationship between recall and precision'is proposed and justified, namely that the recall-fallout graph is convex.
  13. Sparck Jones, K.; Walker, S.; Robertson, S.E.: ¬A probabilistic model of information retrieval : development and comparative experiments - part 1 (2000) 0.01 
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    Source
    Information processing and management. 36(2000) no.6, S.779-808
  14. Sparck Jones, K.; Walker, S.; Robertson, S.E.: ¬A probabilistic model of information retrieval : development and comparative experiments - part 2 (2000) 0.01 
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    Source
    Information processing and management. 36(2000) no.6, S.809-840
  15. Robertson, S.E.: Theories and models in information retrieval (1977) 0.01 
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    Abstract
    This paper is concerned with recent work in the theory of information retrieval. More particularly, it is concerned with theories which tackle the problem of retrieval performance, in a sense which will be explained. The aim is not an exhaustive survey of such work; rather it is an analysis and synthesis of those contributions which I feel to be important or find interesting
  16. Robertson, S.E.; Walker, S.: Some simple effective approximations to the 2-Poisson molde for probabilisitc weighted retrieval (1979) 0.01 
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    Footnote
    Wiederabgedruckt in: Readings in information retrieval. Ed.: K. Sparck Jones u. P. Willett. San Francisco: Morgan Kaufmann 1997. S.345-453.
  17. 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
    Footnote
    Contribution to a thematic issue on Okapi and information retrieval research
  18. MacFarlane, A.; Robertson, S.E.; McCann, J.A.: Parallel computing for passage retrieval (2004) 0.01 
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    Abstract
    In this paper methods for both speeding up passage processing and examining more passages using parallel computers are explored. The number of passages processed are varied in order to examine the effect on retrieval effectiveness and efficiency. The particular algorithm applied has previously been used to good effect in Okapi experiments at TREC. This algorithm and the mechanism for applying parallel computing to speed up processing are described.
    Date
    20. 1.2007 18:30:22
  19. Robertson, S.E.: ¬The probability ranking principle in IR (1977) 0.01 
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    Footnote
    Wiederabgedruckt in: Readings in information retrieval. Ed.: K. Sparck Jones u. P. Willet. San Francisco: Morgan Kaufmann 1997. S.281-286.
  20. Huang, X.; Robertson, S.E.: Application of probilistic methods to Chinese text retrieval (1997) 0.01 
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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
    Footnote
    Contribution to a thematic issue on Okapi and information retrieval research

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