Search (11 results, page 1 of 1)

  • × theme_ss:"Retrievalstudien"
  • × year_i:[1960 TO 1970}
  1. Blagden, J.F.: How much noise in a role-free and link-free co-ordinate indexing system? (1966) 0.03 
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    Abstract
    A study of the number of irrelevant documents retrieved in a co-ordinate indexing system that does not employ eitherr roles or links. These tests were based on one hundred actual inquiries received in the library and therefore an evaluation of recall efficiency is not included. Over half the enquiries produced no noise, but the mean average percentage niose figure was approximately 33 per cent based on a total average retireval figure of eighteen documents per search. Details of the size of the indexed collection, methods of indexing, and an analysis of the reasons for the retrieval of irrelevant documents are discussed, thereby providing information officers who are thinking of installing such a system with some evidence on which to base a decision as to whether or not to utilize these devices
    Source
    Journal of documentation. 22(1966), S.203-209
    Type
    a
  2. Robertson, S.E.: ¬The parametric description of retrieval tests : Part I: The basic parameters (1969) 0.00 
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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.
    Type
    a
  3. Brookes, B.C.: ¬The measure of information retrieval effectiveness proposed by Swets (1968) 0.00 
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    Type
    a
  4. Treu, S.: ¬The browser's retrieval game (1968) 0.00 
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  5. Robertson, S.E.: ¬The parametric description of retrieval tests : Part II: Overall measures (1969) 0.00 
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    Abstract
    Two general requirements for overall measures of retrieval effectiveness are proposed, namely that the measures should be as far as possible independent of generality (this is interpreted to mean that it can be described in terms of recall and fallout), and that it should be able to measure the effectiveness of a performance curve (it should not be restricted to a simple 2X2 table). Several measures that have been proposed are examined with these conditions in mind. It turns out that most of the satisfactory ones are directly or indirectly related to swet's measure A, the area under the recall-fallout curve. In particular, Brookes' measure S and Rocchio's normalized recall are versions of A.
    Type
    a
  6. Lesk, M.E.; Salton, G.: Relevance assements and retrieval system evaluation (1969) 0.00 
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    Abstract
    Two widerly used criteria for evaluating the effectiveness of information retrieval systems are, respectively, the recall and the precision. Since the determiniation of these measures is dependent on a distinction between documents which are relevant to a given query and documents which are not relevant to that query, it has sometimes been claimed that an accurate, generally valid evaluation cannot be based on recall and precision measure. A study was made to determine the effect of variations in relevance assesments do not produce significant variations in average recall and precision. It thus appears that properly computed recall and precision data may represent effectiveness indicators which are gemerally valid for many distinct user classes.
    Type
    a
  7. Good, I.J.: ¬The decision-theory approach to the evaluation of information-retrieval systems (1967) 0.00 
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    Abstract
    It is argued that the evaluation of information-retrieval systems should ultimately be based on the principle of rationality, the maximization of expected utility. In full generality this would involve an estimation of both the cost and value of a system, but the emphasis in this paper is on the problem of value, in terms of which the effiency of the system could be defined. One implication of the discussion is that it is not legitimate to superimpose the 2x2 contingency tables that refer to select/discarded and relevant/irrelevant, correspondending to each request,but it might be all right to superimpose them after applying a monotonic function to the entries. In particular, it is questionable whether a useful statistic is the ratio of the total number of relevant selected documents to the total number of relevant ones, over a sample of requests.
    Type
    a
  8. Salton, G.; Lesk, M.E.: Computer evaluation of indexing and text processing (1968) 0.00 
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  9. Cleverdon, C.W.; Mills, J.: ¬The testing of index language devices (1963) 0.00 
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  10. Lancaster, F.W.: MEDLARS : report on the evaluation of its operating effiency (1961) 0.00 
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  11. Lancaster, F.W.: On the need for role indicators in postcoordinate retrieval systems (1968) 0.00 
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    Abstract
    A summary of the findings of various evaluations of role indicators is given. In general, the results have been negative in that little real evidence for the value of the devices has been presented. The need for roles in various subject fields and in very large systems, is discussed. They can only by justified on purely ecomic grounds - if the added cost involved in their use is offset by substantial reduction in the amount of output screening that must be done by the end user
    Type
    a

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