Search (121 results, page 1 of 7)

  • × theme_ss:"Retrievalstudien"
  1. Information retrieval experiment (1981) 0.08 
    0.07937479 = product of:
  0.15874958 = sum of:
    0.053477753 = weight(_text_:l in 2653) [ClassicSimilarity], result of:
      0.053477753 = score(doc=2653,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.30739886 = fieldWeight in 2653, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.0546875 = fieldNorm(doc=2653)
    0.10527182 = weight(_text_:van in 2653) [ClassicSimilarity], result of:
      0.10527182 = score(doc=2653,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.43129233 = fieldWeight in 2653, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.0546875 = fieldNorm(doc=2653)
  0.5 = coord(2/4)
    Content
    Enthält die Beiträge: ROBERTSON, S.E.: The methodology of information retrieval experiment; RIJSBERGEN, C.J. van: Retrieval effectiveness; BELKIN, N.: Ineffable concepts in information retrieval; TAGUE, J.M.: The pragmatics of information retrieval experimentation; LANCASTER, F.W.: Evaluation within the environment of an operating information service; BARRACLOUGH, E.D.: Opportunities for testing with online systems; KEEN, M.E.: Laboratory tests of manual systems; ODDY, R.N.: Laboratory tests: automatic systems; HEINE, M.D.: Simulation, and simulation experiments; COOPER, W.S.: Gedanken experimentation: an alternative to traditional system testing?; SPARCK JONES, K.: Actual tests - retrieval system tests; EVANS, L.: An experiment: search strategy variation in SDI profiles; SALTON, G.: The Smart environment for retrieval system evaluation - advantage and problem areas
  2. Van der Walt, H.E.A.; Brakel, P.A. van: Method for the evaluation of the retrieval effectiveness of a CD-ROM bibliographic database (1991) 0.08 
    0.07866113 = product of:
  0.15732226 = sum of:
    0.14887685 = weight(_text_:van in 3114) [ClassicSimilarity], result of:
      0.14887685 = score(doc=3114,freq=4.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.60993946 = fieldWeight in 3114, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.0546875 = fieldNorm(doc=3114)
    0.008445405 = product of:
      0.01689081 = sum of:
        0.01689081 = weight(_text_:der in 3114) [ClassicSimilarity], result of:
          0.01689081 = score(doc=3114,freq=2.0), product of:
            0.09777089 = queryWeight, product of:
              2.2337668 = idf(docFreq=12875, maxDocs=44218)
              0.043769516 = queryNorm
            0.17275909 = fieldWeight in 3114, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.2337668 = idf(docFreq=12875, maxDocs=44218)
              0.0546875 = fieldNorm(doc=3114)
      0.5 = coord(1/2)
  0.5 = coord(2/4)
  3. Rijsbergen, C.J. van: Foundations of evaluation (1974) 0.08 
    0.075194165 = product of:
  0.30077666 = sum of:
    0.30077666 = weight(_text_:van in 1078) [ClassicSimilarity], result of:
      0.30077666 = score(doc=1078,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        1.2322638 = fieldWeight in 1078, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.15625 = fieldNorm(doc=1078)
  0.25 = coord(1/4)
  4. Rijsbergen, C.J. van: ¬A test for the separation of relevant and non-relevant documents in experimental retrieval collections (1973) 0.07 
    0.072015665 = product of:
  0.14403133 = sum of:
    0.120310664 = weight(_text_:van in 5002) [ClassicSimilarity], result of:
      0.120310664 = score(doc=5002,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.49290553 = fieldWeight in 5002, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.0625 = fieldNorm(doc=5002)
    0.023720661 = product of:
      0.047441322 = sum of:
        0.047441322 = weight(_text_:22 in 5002) [ClassicSimilarity], result of:
          0.047441322 = score(doc=5002,freq=2.0), product of:
            0.15327339 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043769516 = queryNorm
            0.30952093 = fieldWeight in 5002, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0625 = fieldNorm(doc=5002)
      0.5 = coord(1/2)
  0.5 = coord(2/4)
    Date
    19. 3.1996 11:22:12
  5. Rijsbergen, C.J. van: Retrieval effectiveness (1981) 0.06 
    0.060155332 = product of:
  0.24062133 = sum of:
    0.24062133 = weight(_text_:van in 3147) [ClassicSimilarity], result of:
      0.24062133 = score(doc=3147,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.98581105 = fieldWeight in 3147, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.125 = fieldNorm(doc=3147)
  0.25 = coord(1/4)
  6. Crestani, F.; Rijsbergen, C.J. van: Information retrieval by imaging (1996) 0.05 
    0.054011747 = product of:
  0.108023494 = sum of:
    0.090233 = weight(_text_:van in 6967) [ClassicSimilarity], result of:
      0.090233 = score(doc=6967,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.36967915 = fieldWeight in 6967, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.046875 = fieldNorm(doc=6967)
    0.017790494 = product of:
      0.03558099 = sum of:
        0.03558099 = weight(_text_:22 in 6967) [ClassicSimilarity], result of:
          0.03558099 = score(doc=6967,freq=2.0), product of:
            0.15327339 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043769516 = queryNorm
            0.23214069 = fieldWeight in 6967, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.046875 = fieldNorm(doc=6967)
      0.5 = coord(1/2)
  0.5 = coord(2/4)
    Source
    Information retrieval: new systems and current research. Proceedings of the 16th Research Colloquium of the British Computer Society Information Retrieval Specialist Group, Drymen, Scotland, 22-23 Mar 94. Ed.: R. Leon
  7. Allan, J.; Callan, J.P.; Croft, W.B.; Ballesteros, L.; Broglio, J.; Xu, J.; Shu, H.: INQUERY at TREC-5 (1997) 0.05 
    0.053023808 = product of:
  0.106047615 = sum of:
    0.076396786 = weight(_text_:l in 3103) [ClassicSimilarity], result of:
      0.076396786 = score(doc=3103,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.4391412 = fieldWeight in 3103, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.078125 = fieldNorm(doc=3103)
    0.029650826 = product of:
      0.059301652 = sum of:
        0.059301652 = weight(_text_:22 in 3103) [ClassicSimilarity], result of:
          0.059301652 = score(doc=3103,freq=2.0), product of:
            0.15327339 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043769516 = queryNorm
            0.38690117 = fieldWeight in 3103, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.078125 = fieldNorm(doc=3103)
      0.5 = coord(1/2)
  0.5 = coord(2/4)
    Date
    27. 2.1999 20:55:22
  8. Vegt, A. van der; Zuccon, G.; Koopman, B.: Do better search engines really equate to better clinical decisions? : If not, why not? (2021) 0.04 
    0.040613297 = product of:
  0.081226595 = sum of:
    0.075194165 = weight(_text_:van in 150) [ClassicSimilarity], result of:
      0.075194165 = score(doc=150,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.30806595 = fieldWeight in 150, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.0390625 = fieldNorm(doc=150)
    0.006032432 = product of:
      0.012064864 = sum of:
        0.012064864 = weight(_text_:der in 150) [ClassicSimilarity], result of:
          0.012064864 = score(doc=150,freq=2.0), product of:
            0.09777089 = queryWeight, product of:
              2.2337668 = idf(docFreq=12875, maxDocs=44218)
              0.043769516 = queryNorm
            0.12339935 = fieldWeight in 150, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.2337668 = idf(docFreq=12875, maxDocs=44218)
              0.0390625 = fieldNorm(doc=150)
      0.5 = coord(1/2)
  0.5 = coord(2/4)
  9. Crestani, F.; Ruthven, I.; Sanderson, M.; Rijsbergen, C.J. van: ¬The troubles with using a logical model of IR on a large collection of documents : experimenting retrieval by logical imaging on TREC (1996) 0.04 
    0.037597083 = product of:
  0.15038833 = sum of:
    0.15038833 = weight(_text_:van in 7522) [ClassicSimilarity], result of:
      0.15038833 = score(doc=7522,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.6161319 = fieldWeight in 7522, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.078125 = fieldNorm(doc=7522)
  0.25 = coord(1/4)
  10. Binder, G.; Stahl, M.; Faulborn, L.: Vergleichsuntersuchung MESSENGER-FULCRUM (2000) 0.03 
    0.03271068 = product of:
  0.06542136 = sum of:
    0.053477753 = weight(_text_:l in 4885) [ClassicSimilarity], result of:
      0.053477753 = score(doc=4885,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.30739886 = fieldWeight in 4885, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.0546875 = fieldNorm(doc=4885)
    0.011943607 = product of:
      0.023887213 = sum of:
        0.023887213 = weight(_text_:der in 4885) [ClassicSimilarity], result of:
          0.023887213 = score(doc=4885,freq=4.0), product of:
            0.09777089 = queryWeight, product of:
              2.2337668 = idf(docFreq=12875, maxDocs=44218)
              0.043769516 = queryNorm
            0.24431825 = fieldWeight in 4885, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              2.2337668 = idf(docFreq=12875, maxDocs=44218)
              0.0546875 = fieldNorm(doc=4885)
      0.5 = coord(1/2)
  0.5 = coord(2/4)
    Abstract
    In einem Benutzertest, der im Rahmen der Projektes GIRT stattfand, wurde die Leistungsfähigkeit zweier Retrievalsprachen für die Datenbankrecherche überprüft. Die Ergebnisse werden in diesem Bericht dargestellt: Das System FULCRUM beruht auf automatischer Indexierung und liefert ein nach statistischer Relevanz sortiertes Suchergebnis. Die Standardfreitextsuche des Systems MESSENGER wurde um die intellektuell vom IZ vergebenen Deskriptoren ergänzt. Die Ergebnisse zeigen, dass in FULCRUM das Boole'sche Exakt-Match-Retrieval dem Verktos-Space-Modell (Best-Match-Verfahren) von den Versuchspersonen vorgezogen wurde. Die in MESSENGER realisierte Mischform aus intellektueller und automatischer Indexierung erwies sich gegenüber dem quantitativ-statistischen Ansatz beim Recall als überlegen
  11. Evans, L.: ¬An experiment : search strategy variations in SDI (1981) 0.03 
    0.030558715 = product of:
  0.12223486 = sum of:
    0.12223486 = weight(_text_:l in 3158) [ClassicSimilarity], result of:
      0.12223486 = score(doc=3158,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.70262593 = fieldWeight in 3158, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.125 = fieldNorm(doc=3158)
  0.25 = coord(1/4)
  12. Hancock-Beaulieu, M.; McKenzie, L.; Irving, A.: Evaluative protocols for searching behaviour in online library catalogues (1991) 0.03 
    0.026738876 = product of:
  0.106955506 = sum of:
    0.106955506 = weight(_text_:l in 347) [ClassicSimilarity], result of:
      0.106955506 = score(doc=347,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.6147977 = fieldWeight in 347, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.109375 = fieldNorm(doc=347)
  0.25 = coord(1/4)
  13. Wildemuth, B.; Freund, L.; Toms, E.G.: Untangling search task complexity and difficulty in the context of interactive information retrieval studies (2014) 0.03 
    0.026511904 = product of:
  0.053023808 = sum of:
    0.038198393 = weight(_text_:l in 1786) [ClassicSimilarity], result of:
      0.038198393 = score(doc=1786,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.2195706 = fieldWeight in 1786, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.0390625 = fieldNorm(doc=1786)
    0.014825413 = product of:
      0.029650826 = sum of:
        0.029650826 = weight(_text_:22 in 1786) [ClassicSimilarity], result of:
          0.029650826 = score(doc=1786,freq=2.0), product of:
            0.15327339 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.043769516 = queryNorm
            0.19345059 = fieldWeight in 1786, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0390625 = fieldNorm(doc=1786)
      0.5 = coord(1/2)
  0.5 = coord(2/4)
    Date
    6. 4.2015 19:31:22
  14. Sparck Jones, K.; Rijsbergen, C.J. van: Progress in documentation : Information retrieval test collection (1976) 0.03 
    0.026317956 = product of:
  0.10527182 = sum of:
    0.10527182 = weight(_text_:van in 4161) [ClassicSimilarity], result of:
      0.10527182 = score(doc=4161,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.43129233 = fieldWeight in 4161, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.0546875 = fieldNorm(doc=4161)
  0.25 = coord(1/4)
  15. Kelledy, L.; Smeaton, A.F.: TREC-5 experiments at Dublin City University : Query space reduction, Spanish & character shape encoding (1997) 0.02 
    0.022919035 = product of:
  0.09167614 = sum of:
    0.09167614 = weight(_text_:l in 3089) [ClassicSimilarity], result of:
      0.09167614 = score(doc=3089,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.52696943 = fieldWeight in 3089, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.09375 = fieldNorm(doc=3089)
  0.25 = coord(1/4)
  16. Burnett, M.; Jones, R.; Pape, L.: InTEXT automatic query enhancements in TREC-5 (1997) 0.02 
    0.022919035 = product of:
  0.09167614 = sum of:
    0.09167614 = weight(_text_:l in 3091) [ClassicSimilarity], result of:
      0.09167614 = score(doc=3091,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.52696943 = fieldWeight in 3091, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.09375 = fieldNorm(doc=3091)
  0.25 = coord(1/4)
  17. Kwok, K.L.; Grunfeld, L.: TREC-5 English and Chinese retrieval experiments using PIRCS (1997) 0.02 
    0.022919035 = product of:
  0.09167614 = sum of:
    0.09167614 = weight(_text_:l in 3102) [ClassicSimilarity], result of:
      0.09167614 = score(doc=3102,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.52696943 = fieldWeight in 3102, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.09375 = fieldNorm(doc=3102)
  0.25 = coord(1/4)
  18. Kwok, K.-L.: Ten years of ad hoc retrieval at TREC using PIRCS (2005) 0.02 
    0.022919035 = product of:
  0.09167614 = sum of:
    0.09167614 = weight(_text_:l in 5090) [ClassicSimilarity], result of:
      0.09167614 = score(doc=5090,freq=2.0), product of:
        0.17396861 = queryWeight, product of:
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.043769516 = queryNorm
        0.52696943 = fieldWeight in 5090, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9746525 = idf(docFreq=2257, maxDocs=44218)
          0.09375 = fieldNorm(doc=5090)
  0.25 = coord(1/4)
  19. Abdou, S.; Savoy, J.: Searching in Medline : query expansion and manual indexing evaluation (2008) 0.02 
    0.02255825 = product of:
  0.090233 = sum of:
    0.090233 = weight(_text_:van in 2062) [ClassicSimilarity], result of:
      0.090233 = score(doc=2062,freq=2.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.36967915 = fieldWeight in 2062, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.046875 = fieldNorm(doc=2062)
  0.25 = coord(1/4)
    Abstract
    Based on a relatively large subset representing one third of the Medline collection, this paper evaluates ten different IR models, including recent developments in both probabilistic and language models. We show that the best performing IR models is a probabilistic model developed within the Divergence from Randomness framework [Amati, G., & van Rijsbergen, C.J. (2002) Probabilistic models of information retrieval based on measuring the divergence from randomness. ACM-Transactions on Information Systems 20(4), 357-389], which result in 170% enhancements in mean average precision when compared to the classical tf idf vector-space model. This paper also reports on our impact evaluations on the retrieval effectiveness of manually assigned descriptors (MeSH or Medical Subject Headings), showing that by including these terms retrieval performance can improve from 2.4% to 13.5%, depending on the underling IR model. Finally, we design a new general blind-query expansion approach showing improved retrieval performances compared to those obtained using the Rocchio approach.
  20. Ruthven, I.; Lalmas, M.; Rijsbergen, K. van: Combining and selecting characteristics of information use (2002) 0.02 
    0.021268122 = product of:
  0.08507249 = sum of:
    0.08507249 = weight(_text_:van in 5208) [ClassicSimilarity], result of:
      0.08507249 = score(doc=5208,freq=4.0), product of:
        0.24408463 = queryWeight, product of:
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.043769516 = queryNorm
        0.34853685 = fieldWeight in 5208, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          5.5765896 = idf(docFreq=454, maxDocs=44218)
          0.03125 = fieldNorm(doc=5208)
  0.25 = coord(1/4)
    Abstract
    Ruthven, Lalmas, and van Rijsbergen use traditional term importance measures like inverse document frequency, noise, based upon in-document frequency, and term frequency supplemented by theme value which is calculated from differences of expected positions of words in a text from their actual positions, on the assumption that even distribution indicates term association with a main topic, and context, which is based on a query term's distance from the nearest other query term relative to the average expected distribution of all query terms in the document. They then define document characteristics like specificity, the sum of all idf values in a document over the total terms in the document, or document complexity, measured by the documents average idf value; and information to noise ratio, info-noise, tokens after stopping and stemming over tokens before these processes, measuring the ratio of useful and non-useful information in a document. Retrieval tests are then carried out using each characteristic, combinations of the characteristics, and relevance feedback to determine the correct combination of characteristics. A file ranks independently of query terms by both specificity and info-noise, but if presence of a query term is required unique rankings are generated. Tested on five standard collections the traditional characteristics out preformed the new characteristics, which did, however, out preform random retrieval. All possible combinations of characteristics were also tested both with and without a set of scaling weights applied. All characteristics can benefit by combination with another characteristic or set of characteristics and performance as a single characteristic is a good indicator of performance in combination. Larger combinations tended to be more effective than smaller ones and weighting increased precision measures of middle ranking combinations but decreased the ranking of poorer combinations. The best combinations vary for each collection, and in some collections with the addition of weighting. Finally, with all documents ranked by the all characteristics combination, they take the top 30 documents and calculate the characteristic scores for each term in both the relevant and the non-relevant sets. Then taking for each query term the characteristics whose average was higher for relevant than non-relevant documents the documents are re-ranked. The relevance feedback method of selecting characteristics can select a good set of characteristics for query terms.

Authors

Years

Languages

  • e 72
  • d 46
  • f 1
  • m 1
  • More… Less…

Types

  • a 99
  • s 7
  • m 6
  • r 6
  • el 5
  • x 5
  • p 1
  • More… Less…

Themes

Subjects

Classifications