Search (1 results, page 1 of 1)

  • × author_ss:"Robertson, M."
  • × author_ss:"Willett, P."
  1. Robertson, M.; Willett, P.: ¬An upperbound to the performance of ranked output searching : optimal weighting of query terms using a genetic algorithms (1996) 0.00
    0.004254428 = product of:
      0.034035426 = sum of:
        0.008574939 = weight(_text_:information in 6977) [ClassicSimilarity], result of:
          0.008574939 = score(doc=6977,freq=2.0), product of:
            0.05526379 = queryWeight, product of:
              1.7554779 = idf(docFreq=20772, maxDocs=44218)
              0.031480767 = queryNorm
            0.1551638 = fieldWeight in 6977, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              1.7554779 = idf(docFreq=20772, maxDocs=44218)
              0.0625 = fieldNorm(doc=6977)
        0.025460485 = weight(_text_:retrieval in 6977) [ClassicSimilarity], result of:
          0.025460485 = score(doc=6977,freq=2.0), product of:
            0.095226645 = queryWeight, product of:
              3.024915 = idf(docFreq=5836, maxDocs=44218)
              0.031480767 = queryNorm
            0.26736724 = fieldWeight in 6977, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.024915 = idf(docFreq=5836, maxDocs=44218)
              0.0625 = fieldNorm(doc=6977)
      0.125 = coord(2/16)
    
    Abstract
    Describes the development of a genetic algorithm (GA) for the assignment of weights to query terms in a ranked output document retrieval system. The GA involves a fitness function that is based on full relevance information, and the rankings resulting from the use of these weights are compared with the Robertson-Sparck Jones F4 retrospective relevance weight