Search (6 results, page 1 of 1)

0.03520872 = product of:
  0.0880218 = sum of:
    0.050742455 = weight(_text_:index in 4719) [ClassicSimilarity], result of:
      0.050742455 = score(doc=4719,freq=4.0), product of:
        0.18579477 = queryWeight, product of:
          4.369764 = idf(docFreq=1520, maxDocs=44218)
          0.04251826 = queryNorm
        0.27311024 = fieldWeight in 4719, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          4.369764 = idf(docFreq=1520, maxDocs=44218)
          0.03125 = fieldNorm(doc=4719)
    0.03727935 = weight(_text_:system in 4719) [ClassicSimilarity], result of:
      0.03727935 = score(doc=4719,freq=8.0), product of:
        0.13391352 = queryWeight, product of:
          3.1495528 = idf(docFreq=5152, maxDocs=44218)
          0.04251826 = queryNorm
        0.27838376 = fieldWeight in 4719, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          3.1495528 = idf(docFreq=5152, maxDocs=44218)
          0.03125 = fieldNorm(doc=4719)
  0.4 = coord(2/5)

Abstract

During the past decades, journal impact data obtained from the Journal Citation Reports (JCR) have gained relevance in library management, research management and research evaluation. Hence, both information scientists and bibliometricians share the responsibility towards the users of the JCR to analyse the reliability and validity of its measures thoroughly, to indicate pitfalls and to suggest possible improvements. In this article, ageing patterns are examined in 'formal' use or impact of all scientific journals processed for the Science Citation Index (SCI) during 1981-1995. A new classification system of journals in terms of their ageing characteristics is introduced. This system has been applied to as many as 3,098 journals covered by the Science Citation Index. Following an earlier suggestion by Glnzel and Schoepflin, a maturing and a decline phase are distinguished. From an analysis across all subfields it has been concluded that ageing characteristics are primarily specific to the individual journal rather than to the subfield, while the distribution of journals in terms of slowly or rapidly maturing or declining types is specific to the subfield. It is shown that the cited half life (CHL), printed in the JCR, is an inappropriate measure of decline of journal impact. Following earlier work by Line and others, a more adequate parameter of decline is calculated taking into account the size of annual volumes during a range of fifteen years. For 76 per cent of SCI journals the relative difference between this new parameter and the ISI CHL exceeds 5 per cent. The current JCR journal impact factor is proven to be biased towards journals revealing a rapid maturing and decline in impact. Therefore, a longer term impact factor is proposed, as well as a normalised impact statistic, taking into account citation characteristics of the research subfield covered by a journal and the type of documents published in it. When these new measures are combined with the proposed ageing classification system, they provide a significantly improved picture of a journal's impact to that obtained from the JCR.

0.014352133 = product of:
  0.07176066 = sum of:
    0.07176066 = weight(_text_:index in 5073) [ClassicSimilarity], result of:
      0.07176066 = score(doc=5073,freq=2.0), product of:
        0.18579477 = queryWeight, product of:
          4.369764 = idf(docFreq=1520, maxDocs=44218)
          0.04251826 = queryNorm
        0.3862362 = fieldWeight in 5073, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.369764 = idf(docFreq=1520, maxDocs=44218)
          0.0625 = fieldNorm(doc=5073)
  0.2 = coord(1/5)

Abstract

Discusses basic technical methodological issues with respect to data collection and the construction of bibliometric indicators, particular at the macro or meso level. Focuses on the use of the Science Citation Index. Aims to highlight important decisions that have to be made in the process of data collection and the construction of bibliometric indicators. Illustrates differences in the methodologies applied by several important producers of bibliometric indicators, thus illustrating the complexity of the process of 'standardization'

0.013977095 = product of:
  0.06988547 = sum of:
    0.06988547 = weight(_text_:context in 1049) [ClassicSimilarity], result of:
      0.06988547 = score(doc=1049,freq=6.0), product of:
        0.17622331 = queryWeight, product of:
          4.14465 = idf(docFreq=1904, maxDocs=44218)
          0.04251826 = queryNorm
        0.39657336 = fieldWeight in 1049, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          4.14465 = idf(docFreq=1904, maxDocs=44218)
          0.0390625 = fieldNorm(doc=1049)
  0.2 = coord(1/5)

Abstract

This article analyzes the context of citations within the full text of research articles. It studies articles published in a single journal: the Journal of Informetrics (JOI), in the first year the journal was published, 2007. The analysis classified the citations into in- and out-disciplinary content and looked at their use within the articles' sections such as introduction, literature review, methodology, findings, discussion, and conclusions. In addition, it took into account the age of cited articles. A thematic analysis of these citations was performed in order to identify the evolution of topics within the articles sections and the journal's content. A matrix describing the relationships between the citations' use, and their in- and out-disciplinary focus within the articles' sections is presented. The findings show that an analysis of citations based on their in- and out-disciplinary orientation within the context of the articles' sections can be an indication of the manner by which cross-disciplinary science works, and reveals the connections between the issues, methods, analysis, and conclusions coming from different research disciplines.

0.0071760663 = product of:
  0.03588033 = sum of:
    0.03588033 = weight(_text_:index in 3882) [ClassicSimilarity], result of:
      0.03588033 = score(doc=3882,freq=2.0), product of:
        0.18579477 = queryWeight, product of:
          4.369764 = idf(docFreq=1520, maxDocs=44218)
          0.04251826 = queryNorm
        0.1931181 = fieldWeight in 3882, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.369764 = idf(docFreq=1520, maxDocs=44218)
          0.03125 = fieldNorm(doc=3882)
  0.2 = coord(1/5)

Abstract

Statistical relationships between downloads from ScienceDirect of documents in Elsevier's electronic journal Tetrahedron Letters and citations to these documents recorded in journals processed by the Institute for Scientific Information/Thomson Scientific for the Science Citation Index (SCI) are examined. A synchronous approach revealed that downloads and citations show different patterns of obsolescence of the used materials. The former can be adequately described by a model consisting of the sum of two negative exponential functions, representing an ephemeral and a residual factor, whereas the decline phase of the latter conforms to a simple exponential function with a decay constant statistically similar to that of the downloads residual factor. A diachronous approach showed that, as a cohort of documents grows older, its download distribution becomes more and more skewed, and more statistically similar to its citation distribution. A method is proposed to estimate the effect of citations upon downloads using obsolescence patterns. It was found that during the first 3 months after an article is cited, its number of downloads increased 25% compared to what one would expect this number to be if the article had not been cited. Moreover, more downloads of citing documents led to more downloads of the cited article through the citation. An analysis of 1,190 papers in the journal during a time interval of 2 years after publication date revealed that there is about one citation for every 100 downloads. A Spearman rank correlation coefficient of 0.22 was found between the number of times an article was downloaded and its citation rate recorded in the SCI. When initial downloads-defined as downloads made during the first 3 months after publication-were discarded, the correlation raised to 0.35. However, both outcomes measure the joint effect of downloads upon citation and that of citation upon downloads. Correlating initial downloads to later citation counts, the correlation coefficient drops to 0.11. Findings suggest that initial downloads and citations relate to distinct phases in the process of collecting and processing relevant scientific information that eventually leads to the publication of a journal article.

0.0055919024 = product of:
  0.027959513 = sum of:
    0.027959513 = weight(_text_:system in 3376) [ClassicSimilarity], result of:
      0.027959513 = score(doc=3376,freq=2.0), product of:
        0.13391352 = queryWeight, product of:
          3.1495528 = idf(docFreq=5152, maxDocs=44218)
          0.04251826 = queryNorm
        0.20878783 = fieldWeight in 3376, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.1495528 = idf(docFreq=5152, maxDocs=44218)
          0.046875 = fieldNorm(doc=3376)
  0.2 = coord(1/5)

Abstract

Gives an outline of a new bibliometric database based upon all articles published by authors from the Netherlands and processed during 1980-1993 by ISI for the SCI, SSCI and AHCI. Describes various types of information added to the database: data on articles citing the Dutch publications; detailed citation data on ISI journals and subfields; and a classification system of the main publishing organizations. Also gives an overview of the types of bibliometric indicators constructed. and discusses their relationship to indicators developed by other researchers in the field. Gives 2 applications to illustrate the potentials of the database and of the bibliometric indicators derived from it: one that represents a synthesis of 'classical' macro indicator studies on the one hand and bibliometric analyses of research groups on the other; and a second that gives for the first time a detailed analysis of a country's publications per institutional sector

0.0019202124 = product of:
  0.009601062 = sum of:
    0.009601062 = product of:
      0.028803186 = sum of:
        0.028803186 = weight(_text_:22 in 2646) [ClassicSimilarity], result of:
          0.028803186 = score(doc=2646,freq=2.0), product of:
            0.1488917 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.04251826 = queryNorm
            0.19345059 = fieldWeight in 2646, 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=2646)
      0.33333334 = coord(1/3)
  0.2 = coord(1/5)

Date

22. 1.2016 14:11:17