Search (38 results, page 1 of 2)

  • × theme_ss:"Informetrie"
  • × author_ss:"Egghe, L."
  1. Egghe, L.; Rousseau, R.: Introduction to informetrics : quantitative methods in library, documentation and information science (1990) 0.01
    0.009900499 = product of:
      0.029701497 = sum of:
        0.006246961 = weight(_text_:in in 1515) [ClassicSimilarity], result of:
          0.006246961 = score(doc=1515,freq=2.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.10520181 = fieldWeight in 1515, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0546875 = fieldNorm(doc=1515)
        0.023454536 = weight(_text_:und in 1515) [ClassicSimilarity], result of:
          0.023454536 = score(doc=1515,freq=4.0), product of:
            0.09675359 = queryWeight, product of:
              2.216367 = idf(docFreq=13101, maxDocs=44218)
              0.043654136 = queryNorm
            0.24241515 = fieldWeight in 1515, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              2.216367 = idf(docFreq=13101, maxDocs=44218)
              0.0546875 = fieldNorm(doc=1515)
      0.33333334 = coord(2/6)
    
    Classification
    AN 70400 Allgemeines / Buch- und Bibliothekswesen, Informationswissenschaft / Bibliothekswesen / Bibliotheksverwaltung / Bibliotheksanalyse, -statistik
    RVK
    AN 70400 Allgemeines / Buch- und Bibliothekswesen, Informationswissenschaft / Bibliothekswesen / Bibliotheksverwaltung / Bibliotheksanalyse, -statistik
  2. Egghe, L.; Rousseau, R.: Averaging and globalising quotients of informetric and scientometric data (1996) 0.01
    0.008438686 = product of:
      0.025316058 = sum of:
        0.0075724614 = weight(_text_:in in 7659) [ClassicSimilarity], result of:
          0.0075724614 = score(doc=7659,freq=4.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.12752387 = fieldWeight in 7659, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.046875 = fieldNorm(doc=7659)
        0.017743597 = product of:
          0.035487194 = sum of:
            0.035487194 = weight(_text_:22 in 7659) [ClassicSimilarity], result of:
              0.035487194 = score(doc=7659,freq=2.0), product of:
                0.15286934 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.043654136 = queryNorm
                0.23214069 = fieldWeight in 7659, 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=7659)
          0.5 = coord(1/2)
      0.33333334 = coord(2/6)
    
    Abstract
    It is possible, using ISI's Journal Citation Report (JCR), to calculate average impact factors (AIF) for LCR's subject categories but it can be more useful to know the global Impact Factor (GIF) of a subject category and compare the 2 values. Reports results of a study to compare the relationships between AIFs and GIFs of subjects, based on the particular case of the average impact factor of a subfield versus the impact factor of this subfield as a whole, the difference being studied between an average of quotients, denoted as AQ, and a global average, obtained as a quotient of averages, and denoted as GQ. In the case of impact factors, AQ becomes the average impact factor of a field, and GQ becomes its global impact factor. Discusses a number of applications of this technique in the context of informetrics and scientometrics
    Source
    Journal of information science. 22(1996) no.3, S.165-170
  3. Egghe, L.: Empirical and combinatorial study of country occurrences in multi-authored papers (2006) 0.01
    0.006524559 = product of:
      0.019573677 = sum of:
        0.010096614 = weight(_text_:in in 81) [ClassicSimilarity], result of:
          0.010096614 = score(doc=81,freq=16.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.17003182 = fieldWeight in 81, product of:
              4.0 = tf(freq=16.0), with freq of:
                16.0 = termFreq=16.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.03125 = fieldNorm(doc=81)
        0.009477063 = weight(_text_:und in 81) [ClassicSimilarity], result of:
          0.009477063 = score(doc=81,freq=2.0), product of:
            0.09675359 = queryWeight, product of:
              2.216367 = idf(docFreq=13101, maxDocs=44218)
              0.043654136 = queryNorm
            0.09795051 = fieldWeight in 81, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              2.216367 = idf(docFreq=13101, maxDocs=44218)
              0.03125 = fieldNorm(doc=81)
      0.33333334 = coord(2/6)
    
    Abstract
    Papers written by several authors can be classified according to the countries of the author affiliations. The empirical part of this paper consists of two datasets. One dataset consists of 1,035 papers retrieved via the search "pedagog*" in the years 2004 and 2005 (up to October) in Academic Search Elite which is a case where phi(m) = the number of papers with m =1, 2,3 ... authors is decreasing, hence most of the papers have a low number of authors. Here we find that #, m = the number of times a country occurs j times in a m-authored paper, j =1, ..., m-1 is decreasing and that # m, m is much higher than all the other #j, m values. The other dataset consists of 3,271 papers retrieved via the search "enzyme" in the year 2005 (up to October) in the same database which is a case of a non-decreasing phi(m): most papers have 3 or 4 authors and we even find many papers with a much higher number of authors. In this case we show again that # m, m is much higher than the other #j, m values but that #j, m is not decreasing anymore in j =1, ..., m-1, although #1, m is (apart from # m, m) the largest number amongst the #j,m. The combinatorial part gives a proof of the fact that #j,m decreases for j = 1, m-1, supposing that all cases are equally possible. This shows that the first dataset is more conform with this model than the second dataset. Explanations for these findings are given. From the data we also find the (we think: new) distribution of number of papers with n =1, 2,3,... countries (i.e. where there are n different countries involved amongst the m (a n) authors of a paper): a fast decreasing function e.g. as a power law with a very large Lotka exponent.
    Source
    Information - Wissenschaft und Praxis. 57(2006) H.8, S.427-432
  4. Egghe, L.: Untangling Herdan's law and Heaps' law : mathematical and informetric arguments (2007) 0.00
    0.0024665273 = product of:
      0.014799163 = sum of:
        0.014799163 = weight(_text_:in in 271) [ClassicSimilarity], result of:
          0.014799163 = score(doc=271,freq=22.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.24922498 = fieldWeight in 271, product of:
              4.690416 = tf(freq=22.0), with freq of:
                22.0 = termFreq=22.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0390625 = fieldNorm(doc=271)
      0.16666667 = coord(1/6)
    
    Abstract
    Herdan's law in linguistics and Heaps' law in information retrieval are different formulations of the same phenomenon. Stated briefly and in linguistic terms they state that vocabularies' sizes are concave increasing power laws of texts' sizes. This study investigates these laws from a purely mathematical and informetric point of view. A general informetric argument shows that the problem of proving these laws is, in fact, ill-posed. Using the more general terminology of sources and items, the author shows by presenting exact formulas from Lotkaian informetrics that the total number T of sources is not only a function of the total number A of items, but is also a function of several parameters (e.g., the parameters occurring in Lotka's law). Consequently, it is shown that a fixed T(or A) value can lead to different possible A (respectively, T) values. Limiting the T(A)-variability to increasing samples (e.g., in a text as done in linguistics) the author then shows, in a purely mathematical way, that for large sample sizes T~ A**phi, where phi is a constant, phi < 1 but close to 1, hence roughly, Heaps' or Herdan's law can be proved without using any linguistic or informetric argument. The author also shows that for smaller samples, a is not a constant but essentially decreases as confirmed by practical examples. Finally, an exact informetric argument on random sampling in the items shows that, in most cases, T= T(A) is a concavely increasing function, in accordance with practical examples.
  5. Egghe, L.; Rousseau, R.: Duality in information retrieval and the hypegeometric distribution (1997) 0.00
    0.0023797948 = product of:
      0.014278769 = sum of:
        0.014278769 = weight(_text_:in in 647) [ClassicSimilarity], result of:
          0.014278769 = score(doc=647,freq=8.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.24046129 = fieldWeight in 647, product of:
              2.828427 = tf(freq=8.0), with freq of:
                8.0 = termFreq=8.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0625 = fieldNorm(doc=647)
      0.16666667 = coord(1/6)
    
    Abstract
    Asserts that duality is an important topic in informetrics, especially in connection with the classical informetric laws. Yet this concept is less studied in information retrieval. It deals with the unification or symmetry between queries and documents, search formulation versus indexing, and relevant versus retrieved documents. Elaborates these ideas and highlights the connection with the hypergeometric distribution
  6. Egghe, L.: Mathematical theory of the h- and g-index in case of fractional counting of authorship (2008) 0.00
    0.0023611297 = product of:
      0.014166778 = sum of:
        0.014166778 = weight(_text_:in in 2004) [ClassicSimilarity], result of:
          0.014166778 = score(doc=2004,freq=14.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.23857531 = fieldWeight in 2004, product of:
              3.7416575 = tf(freq=14.0), with freq of:
                14.0 = termFreq=14.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.046875 = fieldNorm(doc=2004)
      0.16666667 = coord(1/6)
    
    Abstract
    This article studies the h-index (Hirsch index) and the g-index of authors, in case one counts authorship of the cited articles in a fractional way. There are two ways to do this: One counts the citations to these papers in a fractional way or one counts the ranks of the papers in a fractional way as credit for an author. In both cases, we define the fractional h- and g-indexes, and we present inequalities (both upper and lower bounds) between these fractional h- and g-indexes and their corresponding unweighted values (also involving, of course, the coauthorship distribution). Wherever applicable, examples and counterexamples are provided. In a concrete example (the publication citation list of the present author), we make explicit calculations of these fractional h- and g-indexes and show that they are not very different from the unweighted ones.
  7. Egghe, L.; Rousseau, R.; Rousseau, S.: TOP-curves (2007) 0.00
    0.0023281053 = product of:
      0.013968632 = sum of:
        0.013968632 = weight(_text_:in in 50) [ClassicSimilarity], result of:
          0.013968632 = score(doc=50,freq=10.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.23523843 = fieldWeight in 50, product of:
              3.1622777 = tf(freq=10.0), with freq of:
                10.0 = termFreq=10.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0546875 = fieldNorm(doc=50)
      0.16666667 = coord(1/6)
    
    Abstract
    Several characteristics of classical Lorenz curves make them unsuitable for the study of a group of topperformers. TOP-curves, defined as a kind of mirror image of TIP-curves used in poverty studies, are shown to possess the properties necessary for adequate empirical ranking of various data arrays, based on the properties of the highest performers (i.e., the core). TOP-curves and essential TOP-curves, also introduced in this article, simultaneously represent the incidence, intensity, and inequality among the top. It is shown that TOPdominance partial order, introduced in this article, is stronger than Lorenz dominance order. In this way, this article contributes to the study of cores, a central issue in applied informetrics.
  8. Egghe, L.: Type/Token-Taken informetrics (2003) 0.00
    0.0021034614 = product of:
      0.012620768 = sum of:
        0.012620768 = weight(_text_:in in 1608) [ClassicSimilarity], result of:
          0.012620768 = score(doc=1608,freq=16.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.21253976 = fieldWeight in 1608, product of:
              4.0 = tf(freq=16.0), with freq of:
                16.0 = termFreq=16.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0390625 = fieldNorm(doc=1608)
      0.16666667 = coord(1/6)
    
    Abstract
    Type/Token-Taken informetrics is a new part of informetrics that studies the use of items rather than the items itself. Here, items are the objects that are produced by the sources (e.g., journals producing articles, authors producing papers, etc.). In linguistics a source is also called a type (e.g., a word), and an item a token (e.g., the use of words in texts). In informetrics, types that occur often, for example, in a database will also be requested often, for example, in information retrieval. The relative use of these occurrences will be higher than their relative occurrences itself; hence, the name Type/ Token-Taken informetrics. This article studies the frequency distribution of Type/Token-Taken informetrics, starting from the one of Type/Token informetrics (i.e., source-item relationships). We are also studying the average number my* of item uses in Type/Token-Taken informetrics and compare this with the classical average number my in Type/Token informetrics. We show that my* >= my always, and that my* is an increasing function of my. A method is presented to actually calculate my* from my, and a given a, which is the exponent in Lotka's frequency distribution of Type/Token informetrics. We leave open the problem of developing non-Lotkaian Type/TokenTaken informetrics.
  9. Egghe, L.: Sampling and concentration values of incomplete bibliographies (2002) 0.00
    0.0020823204 = product of:
      0.012493922 = sum of:
        0.012493922 = weight(_text_:in in 450) [ClassicSimilarity], result of:
          0.012493922 = score(doc=450,freq=8.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.21040362 = fieldWeight in 450, product of:
              2.828427 = tf(freq=8.0), with freq of:
                8.0 = termFreq=8.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0546875 = fieldNorm(doc=450)
      0.16666667 = coord(1/6)
    
    Abstract
    This article studies concentration aspects of bibliographies. More, in particular, we study the impact of incompleteness of such a bibliography on its concentration values (i.e., its degree of inequality of production of its sources). Incompleteness is modeled by sampling in the complete bibliography. The model is general enough to comprise truncation of a bibliography as well as a systematic sample on sources or items. In all cases we prove that the sampled bibliography (or incomplete one) has a higher concentration value than the complete one. These models, hence, shed some light on the measurement of production inequality in incomplete bibliographies.
  10. Egghe, L.: ¬A rationale for the Hirsch-index rank-order distribution and a comparison with the impact factor rank-order distribution (2009) 0.00
    0.0020823204 = product of:
      0.012493922 = sum of:
        0.012493922 = weight(_text_:in in 3124) [ClassicSimilarity], result of:
          0.012493922 = score(doc=3124,freq=8.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.21040362 = fieldWeight in 3124, product of:
              2.828427 = tf(freq=8.0), with freq of:
                8.0 = termFreq=8.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0546875 = fieldNorm(doc=3124)
      0.16666667 = coord(1/6)
    
    Abstract
    We present a rationale for the Hirsch-index rank-order distribution and prove that it is a power law (hence a straight line in the log-log scale). This is confirmed by experimental data of Pyykkö and by data produced in this article on 206 mathematics journals. This distribution is of a completely different nature than the impact factor (IF) rank-order distribution which (as proved in a previous article) is S-shaped. This is also confirmed by our example. Only in the log-log scale of the h-index distribution do we notice a concave deviation of the straight line for higher ranks. This phenomenon is discussed.
  11. Egghe, L.: ¬A new short proof of Naranan's theorem, explaining Lotka's law and Zipf's law (2010) 0.00
    0.0020823204 = product of:
      0.012493922 = sum of:
        0.012493922 = weight(_text_:in in 3432) [ClassicSimilarity], result of:
          0.012493922 = score(doc=3432,freq=8.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.21040362 = fieldWeight in 3432, product of:
              2.828427 = tf(freq=8.0), with freq of:
                8.0 = termFreq=8.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0546875 = fieldNorm(doc=3432)
      0.16666667 = coord(1/6)
    
    Abstract
    Naranan's important theorem, published in Nature in 1970, states that if the number of journals grows exponentially and if the number of articles in each journal grows exponentially (at the same rate for each journal), then the system satisfies Lotka's law and a formula for the Lotka's exponent is given in function of the growth rates of the journals and the articles. This brief communication re-proves this result by showing that the system satisfies Zipf's law, which is equivalent with Lotka's law. The proof is short and algebraic and does not use infinitesimal arguments.
  12. Egghe, L.: On the law of Zipf-Mandelbrot for multi-word phrases (1999) 0.00
    0.0020609628 = product of:
      0.012365777 = sum of:
        0.012365777 = weight(_text_:in in 3058) [ClassicSimilarity], result of:
          0.012365777 = score(doc=3058,freq=6.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.2082456 = fieldWeight in 3058, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0625 = fieldNorm(doc=3058)
      0.16666667 = coord(1/6)
    
    Abstract
    This article studies the probabilities of the occurence of multi-word (m-word) phrases (m=2,3,...) in relation to the probabilities of occurence of the single words. It is well known that, in the latter case, the lae of Zipf is valid (i.e., a power law). We prove that in the case of m-word phrases (m>=2), this is not the case. We present 2 independent proof of this
  13. Egghe, L.: Mathematical theories of citation (1998) 0.00
    0.0020609628 = product of:
      0.012365777 = sum of:
        0.012365777 = weight(_text_:in in 5125) [ClassicSimilarity], result of:
          0.012365777 = score(doc=5125,freq=6.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.2082456 = fieldWeight in 5125, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0625 = fieldNorm(doc=5125)
      0.16666667 = coord(1/6)
    
    Abstract
    Focuses on possible mathematical theories of citation and on the intrinsic problems related to it. Sheds light on aspects of mathematical complexity as encountered in, for example, fractal theory and Mandelbrot's law. Also discusses dynamical aspects of citation theory as reflected in evolutions of journal rankings, centres of gravity or of the set of source journals. Makes some comments in this connection on growth and obsolescence
  14. Egghe, L.; Liang, L.; Rousseau, R.: ¬A relation between h-index and impact factor in the power-law model (2009) 0.00
    0.0020609628 = product of:
      0.012365777 = sum of:
        0.012365777 = weight(_text_:in in 6759) [ClassicSimilarity], result of:
          0.012365777 = score(doc=6759,freq=6.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.2082456 = fieldWeight in 6759, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0625 = fieldNorm(doc=6759)
      0.16666667 = coord(1/6)
    
    Abstract
    Using a power-law model, the two best-known topics in citation analysis, namely the impact factor and the Hirsch index, are unified into one relation (not a function). The validity of our model is, at least in a qualitative way, confirmed by real data.
  15. Egghe, L.: Dynamic h-index : the Hirsch index in function of time (2007) 0.00
    0.0020609628 = product of:
      0.012365777 = sum of:
        0.012365777 = weight(_text_:in in 147) [ClassicSimilarity], result of:
          0.012365777 = score(doc=147,freq=6.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.2082456 = fieldWeight in 147, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0625 = fieldNorm(doc=147)
      0.16666667 = coord(1/6)
    
    Abstract
    When there are a group of articles and the present time is fixed we can determine the unique number h being the number of articles that received h or more citations while the other articles received a number of citations which is not larger than h. In this article, the time dependence of the h-index is determined. This is important to describe the expected career evolution of a scientist's work or of a journal's production in a fixed year.
  16. Egghe, L.: ¬A noninformetric analysis of the relationship between citation age and journal productivity (2001) 0.00
    0.0019955188 = product of:
      0.011973113 = sum of:
        0.011973113 = weight(_text_:in in 5685) [ClassicSimilarity], result of:
          0.011973113 = score(doc=5685,freq=10.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.20163295 = fieldWeight in 5685, product of:
              3.1622777 = tf(freq=10.0), with freq of:
                10.0 = termFreq=10.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.046875 = fieldNorm(doc=5685)
      0.16666667 = coord(1/6)
    
    Abstract
    A problem, raised by Wallace (JASIS, 37,136-145,1986), on the relation between the journal's median citation age and its number of articles is studied. Leaving open the problem as such, we give a statistical explanation of this relationship, when replacing "median" by "mean" in Wallace's problem. The cloud of points, found by Wallace, is explained in this sense that the points are scattered over the area in first quadrant, limited by a curve of the form y=1 + E/x**2 where E is a constant. This curve is obtained by using the Central Limit Theorem in statistics and, hence, has no intrinsic informetric foundation. The article closes with some reflections on explanations of regularities in informetrics, based on statistical, probabilistic or informetric results, or on a combination thereof
  17. Egghe, L.: Influence of adding or deleting items and sources on the h-index (2010) 0.00
    0.0019955188 = product of:
      0.011973113 = sum of:
        0.011973113 = weight(_text_:in in 3336) [ClassicSimilarity], result of:
          0.011973113 = score(doc=3336,freq=10.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.20163295 = fieldWeight in 3336, product of:
              3.1622777 = tf(freq=10.0), with freq of:
                10.0 = termFreq=10.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.046875 = fieldNorm(doc=3336)
      0.16666667 = coord(1/6)
    
    Abstract
    Adding or deleting items such as self-citations has an influence on the h-index of an author. This influence will be proved mathematically in this article. We hereby prove the experimental finding in E. Gianoli and M.A. Molina-Montenegro ([2009]) that the influence of adding or deleting self-citations on the h-index is greater for low values of the h-index. Why this is logical also is shown by a simple theoretical example. Adding or deleting sources such as adding or deleting minor contributions of an author also has an influence on the h-index of this author; this influence is modeled in this article. This model explains some practical examples found in X. Hu, R. Rousseau, and J. Chen (in press).
  18. Egghe, L.: ¬The power of power laws and an interpretation of Lotkaian informetric systems as self-similar fractals (2005) 0.00
    0.0019676082 = product of:
      0.011805649 = sum of:
        0.011805649 = weight(_text_:in in 3466) [ClassicSimilarity], result of:
          0.011805649 = score(doc=3466,freq=14.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.19881277 = fieldWeight in 3466, product of:
              3.7416575 = tf(freq=14.0), with freq of:
                14.0 = termFreq=14.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0390625 = fieldNorm(doc=3466)
      0.16666667 = coord(1/6)
    
    Abstract
    Power laws as defined in 1926 by A. Lotka are increasing in importance because they have been found valid in varied social networks including the Internet. In this article some unique properties of power laws are proven. They are shown to characterize functions with the scalefree property (also called seif-similarity property) as weIl as functions with the product property. Power laws have other desirable properties that are not shared by exponential laws, as we indicate in this paper. Specifically, Naranan (1970) proves the validity of Lotka's law based on the exponential growth of articles in journals and of the number of journals. His argument is reproduced here and a discrete-time argument is also given, yielding the same law as that of Lotka. This argument makes it possible to interpret the information production process as a seif-similar fractal and show the relation between Lotka's exponent and the (seif-similar) fractal dimension of the system. Lotkaian informetric systems are seif-similar fractals, a fact revealed by Mandelbrot (1977) in relation to nature, but is also true for random texts, which exemplify a very special type of informetric system.
  19. Egghe, L.: ¬The influence of transformations on the h-index and the g-index (2008) 0.00
    0.0018033426 = product of:
      0.010820055 = sum of:
        0.010820055 = weight(_text_:in in 1881) [ClassicSimilarity], result of:
          0.010820055 = score(doc=1881,freq=6.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.1822149 = fieldWeight in 1881, product of:
              2.4494898 = tf(freq=6.0), with freq of:
                6.0 = termFreq=6.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.0546875 = fieldNorm(doc=1881)
      0.16666667 = coord(1/6)
    
    Abstract
    In a previous article, we introduced a general transformation on sources and one on items in an arbitrary information production process (IPP). In this article, we investigate the influence of these transformations on the h-index and on the g-index. General formulae that describe this influence are presented. These are applied to the case that the size-frequency function is Lotkaian (i.e., is a decreasing power function). We further show that the h-index of the transformed IPP belongs to the interval bounded by the two transformations of the h-index of the original IPP, and we also show that this property is not true for the g-index.
  20. Egghe, L.: Expansion of the field of informetrics : the second special issue (2006) 0.00
    0.0017848461 = product of:
      0.010709076 = sum of:
        0.010709076 = weight(_text_:in in 7119) [ClassicSimilarity], result of:
          0.010709076 = score(doc=7119,freq=2.0), product of:
            0.059380736 = queryWeight, product of:
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.043654136 = queryNorm
            0.18034597 = fieldWeight in 7119, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              1.3602545 = idf(docFreq=30841, maxDocs=44218)
              0.09375 = fieldNorm(doc=7119)
      0.16666667 = coord(1/6)
    
    Footnote
    Einführung in ein "Special Issue on Informetrics"