Search (4 results, page 1 of 1)

0.0132371 = product of:
  0.0397113 = sum of:
    0.0397113 = product of:
      0.0794226 = sum of:
        0.0794226 = weight(_text_:publishing in 3376) [ClassicSimilarity], result of:
          0.0794226 = score(doc=3376,freq=2.0), product of:
            0.24522576 = queryWeight, product of:
              4.885643 = idf(docFreq=907, maxDocs=44218)
              0.05019314 = queryNorm
            0.32387543 = fieldWeight in 3376, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              4.885643 = idf(docFreq=907, maxDocs=44218)
              0.046875 = fieldNorm(doc=3376)
      0.5 = coord(1/2)
  0.33333334 = coord(1/3)

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

0.011301385 = product of:
  0.033904154 = sum of:
    0.033904154 = weight(_text_:electronic in 3882) [ClassicSimilarity], result of:
      0.033904154 = score(doc=3882,freq=2.0), product of:
        0.19623034 = queryWeight, product of:
          3.9095051 = idf(docFreq=2409, maxDocs=44218)
          0.05019314 = queryNorm
        0.17277734 = fieldWeight in 3882, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.9095051 = idf(docFreq=2409, maxDocs=44218)
          0.03125 = fieldNorm(doc=3882)
  0.33333334 = coord(1/3)

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.

0.011030916 = product of:
  0.03309275 = sum of:
    0.03309275 = product of:
      0.0661855 = sum of:
        0.0661855 = weight(_text_:publishing in 621) [ClassicSimilarity], result of:
          0.0661855 = score(doc=621,freq=2.0), product of:
            0.24522576 = queryWeight, product of:
              4.885643 = idf(docFreq=907, maxDocs=44218)
              0.05019314 = queryNorm
            0.26989618 = fieldWeight in 621, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              4.885643 = idf(docFreq=907, maxDocs=44218)
              0.0390625 = fieldNorm(doc=621)
      0.5 = coord(1/2)
  0.33333334 = coord(1/3)

Abstract

This article statistically analyzes how the citation impact of articles deposited in the Condensed Matter section of the preprint server ArXiv (hosted by Cornell University), and subsequently published in a scientific journal, compares to that of articles in the same journal that were not deposited in the archive. Its principal aim is to further illustrate and roughly estimate the effect of two factors, early view and quality bias, on differences in citation impact between these two sets of papers, using citation data from Thomson Scientific's Web of Science. It presents estimates for a number of journals in the field of condensed matter physics. To discriminate between an open access effect and an early view effect, longitudinal citation data were analyzed covering a time period as long as 7 years. Quality bias was measured by calculating ArXiv citation impact differentials at the level of individual authors publishing in a journal, taking into account coauthorship. The analysis provided evidence of a strong quality bias and early view effect. Correcting for these effects, there is in a sample of six condensed matter physics journals studied in detail no sign of a general open access advantage of papers deposited in ArXiv. The study does provide evidence that ArXiv accelerates citation due to the fact that ArXiv makes papers available earlier rather than makes them freely available.

0.0056670653 = product of:
  0.017001195 = sum of:
    0.017001195 = product of:
      0.03400239 = sum of:
        0.03400239 = weight(_text_:22 in 2646) [ClassicSimilarity], result of:
          0.03400239 = score(doc=2646,freq=2.0), product of:
            0.17576782 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.05019314 = 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)
      0.5 = coord(1/2)
  0.33333334 = coord(1/3)

Date

22. 1.2016 14:11:17