Search (2 results, page 1 of 1)

  • × author_ss:"Costas, R."
  • × author_ss:"Raan, A.F.J. van"
  • × theme_ss:"Informetrie"
  1. Costas, R.; Bordons, M.; Leeuwen, T.N. van; Raan, A.F.J. van: Scaling rules in the science system : Influence of field-specific citation characteristics on the impact of individual researchers (2009) 0.02
    0.01974305 = product of:
      0.0394861 = sum of:
        0.0394861 = sum of:
          0.008285859 = weight(_text_:a in 2759) [ClassicSimilarity], result of:
            0.008285859 = score(doc=2759,freq=12.0), product of:
              0.053105544 = queryWeight, product of:
                1.153047 = idf(docFreq=37942, maxDocs=44218)
                0.046056706 = queryNorm
              0.15602624 = fieldWeight in 2759, product of:
                3.4641016 = tf(freq=12.0), with freq of:
                  12.0 = termFreq=12.0
                1.153047 = idf(docFreq=37942, maxDocs=44218)
                0.0390625 = fieldNorm(doc=2759)
          0.03120024 = weight(_text_:22 in 2759) [ClassicSimilarity], result of:
            0.03120024 = score(doc=2759,freq=2.0), product of:
              0.16128273 = queryWeight, product of:
                3.5018296 = idf(docFreq=3622, maxDocs=44218)
                0.046056706 = queryNorm
              0.19345059 = fieldWeight in 2759, 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=2759)
      0.5 = coord(1/2)
    
    Abstract
    The representation of science as a citation density landscape and the study of scaling rules with the field-specific citation density as a main topological property was previously analyzed at the level of research groups. Here, the focus is on the individual researcher. In this new analysis, the size dependence of several main bibliometric indicators for a large set of individual researchers is explored. Similar results as those previously observed for research groups are described for individual researchers. The total number of citations received by scientists increases in a cumulatively advantageous way as a function of size (in terms of number of publications) for researchers in three areas: Natural Resources, Biology & Biomedicine, and Materials Science. This effect is stronger for researchers in low citation density fields. Differences found among thematic areas with different citation densities are discussed.
    Date
    22. 3.2009 19:02:48
    Type
    a
  2. Costas, R.; Leeuwen, T.N. van; Raan, A.F.J. van: Is scientific literature subject to a 'Sell-By-Date'? : a general methodology to analyze the 'durability' of scientific documents (2010) 0.00
    0.0018909799 = product of:
      0.0037819599 = sum of:
        0.0037819599 = product of:
          0.0075639198 = sum of:
            0.0075639198 = weight(_text_:a in 3333) [ClassicSimilarity], result of:
              0.0075639198 = score(doc=3333,freq=10.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.14243183 = fieldWeight in 3333, product of:
                  3.1622777 = tf(freq=10.0), with freq of:
                    10.0 = termFreq=10.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=3333)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    The study of the citation histories and ageing of documents are topics that have been addressed from several perspectives, especially in the analysis of documents with delayed recognition or sleeping beauties. However, there is no general methodology that can be extensively applied for different time periods or research fields. In this article, a new methodology for the general analysis of the ageing and durability of scientific papers is presented. This methodology classifies documents into three general types: delayed documents, which receive the main part of their citations later than normal documents; flashes in the pan, which receive citations immediately after their publication but are not cited in the long term; and normal documents, documents with a typical distribution of citations over time. These three types of durability have been analyzed considering the whole population of documents in the Web of Science with at least 5 external citations (i.e., not considering self-citations). Several patterns related to the three types of durability have been found and the potential for further research of the developed methodology is discussed.
    Type
    a