Search (3 results, page 1 of 1)

  • × author_ss:"Eck, N.J. van"
  • × theme_ss:"Informetrie"
  • × year_i:[2010 TO 2020}
  1. Waltman, L.; Eck, N.J. van: ¬The inconsistency of the h-index : the case of web accessibility in Western European countries (2012) 0.01
    0.013705668 = product of:
      0.027411336 = sum of:
        0.027411336 = product of:
          0.054822672 = sum of:
            0.054822672 = weight(_text_:h in 40) [ClassicSimilarity], result of:
              0.054822672 = score(doc=40,freq=20.0), product of:
                0.10526253 = queryWeight, product of:
                  2.4844491 = idf(docFreq=10020, maxDocs=44218)
                  0.04236856 = queryNorm
                0.5208185 = fieldWeight in 40, product of:
                  4.472136 = tf(freq=20.0), with freq of:
                    20.0 = termFreq=20.0
                  2.4844491 = idf(docFreq=10020, maxDocs=44218)
                  0.046875 = fieldNorm(doc=40)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    The h-index is a popular bibliometric indicator for assessing individual scientists. We criticize the h-index from a theoretical point of view. We argue that for the purpose of measuring the overall scientific impact of a scientist (or some other unit of analysis), the h-index behaves in a counterintuitive way. In certain cases, the mechanism used by the h-index to aggregate publication and citation statistics into a single number leads to inconsistencies in the way in which scientists are ranked. Our conclusion is that the h-index cannot be considered an appropriate indicator of a scientist's overall scientific impact. Based on recent theoretical insights, we discuss what kind of indicators can be used as an alternative to the h-index. We pay special attention to the highly cited publications indicator. This indicator has a lot in common with the h-index, but unlike the h-index it does not produce inconsistent rankings.
    Object
    h-index
  2. Eck, N.J. van; Waltman, L.; Dekker, R.; Berg, J. van den: ¬A comparison of two techniques for bibliometric mapping : multidimensional scaling and VOS (2010) 0.00
    0.004864324 = product of:
      0.009728648 = sum of:
        0.009728648 = product of:
          0.058371887 = sum of:
            0.058371887 = weight(_text_:authors in 4112) [ClassicSimilarity], result of:
              0.058371887 = score(doc=4112,freq=2.0), product of:
                0.19315039 = queryWeight, product of:
                  4.558814 = idf(docFreq=1258, maxDocs=44218)
                  0.04236856 = queryNorm
                0.30220953 = fieldWeight in 4112, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  4.558814 = idf(docFreq=1258, maxDocs=44218)
                  0.046875 = fieldNorm(doc=4112)
          0.16666667 = coord(1/6)
      0.5 = coord(1/2)
    
    Abstract
    VOS is a new mapping technique that can serve as an alternative to the well-known technique of multidimensional scaling (MDS). We present an extensive comparison between the use of MDS and the use of VOS for constructing bibliometric maps. In our theoretical analysis, we show the mathematical relation between the two techniques. In our empirical analysis, we use the techniques for constructing maps of authors, journals, and keywords. Two commonly used approaches to bibliometric mapping, both based on MDS, turn out to produce maps that suffer from artifacts. Maps constructed using VOS turn out not to have this problem. We conclude that in general maps constructed using VOS provide a more satisfactory representation of a dataset than maps constructed using well-known MDS approaches.
  3. Colavizza, G.; Boyack, K.W.; Eck, N.J. van; Waltman, L.: ¬The closer the better : similarity of publication pairs at different cocitation levels (2018) 0.00
    0.004864324 = product of:
      0.009728648 = sum of:
        0.009728648 = product of:
          0.058371887 = sum of:
            0.058371887 = weight(_text_:authors in 4214) [ClassicSimilarity], result of:
              0.058371887 = score(doc=4214,freq=2.0), product of:
                0.19315039 = queryWeight, product of:
                  4.558814 = idf(docFreq=1258, maxDocs=44218)
                  0.04236856 = queryNorm
                0.30220953 = fieldWeight in 4214, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  4.558814 = idf(docFreq=1258, maxDocs=44218)
                  0.046875 = fieldNorm(doc=4214)
          0.16666667 = coord(1/6)
      0.5 = coord(1/2)
    
    Abstract
    We investigated the similarities of pairs of articles that are cocited at the different cocitation levels of the journal, article, section, paragraph, sentence, and bracket. Our results indicate that textual similarity, intellectual overlap (shared references), author overlap (shared authors), proximity in publication time all rise monotonically as the cocitation level gets lower (from journal to bracket). While the main gain in similarity happens when moving from journal to article cocitation, all level changes entail an increase in similarity, especially section to paragraph and paragraph to sentence/bracket levels. We compared the results from four journals over the years 2010-2015: Cell, the European Journal of Operational Research, Physics Letters B, and Research Policy, with consistent general outcomes and some interesting differences. Our findings motivate the use of granular cocitation information as defined by meaningful units of text, with implications for, among others, the elaboration of maps of science and the retrieval of scholarly literature.