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H-indexes & Aging

H-indexes & Aging. Peter Ingwersen Royal School of LIS, Denmark University College, Oslo, Norway, 2011. H -indexes (2005 …).

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H-indexes & Aging

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  1. H-indexes & Aging Peter Ingwersen Royal School of LIS, Denmark University College, Oslo, Norway, 2011

  2. H-indexes (2005 …) • Hirsch's h-index Proposed by J.E. Hirsch in his paper An index to quantify an individual's scientific research output, arXiv:physics/0508025 v5 29 Sep 2005. It aims to provide a robust single-number metric of an academic's impact, combining quality with quantity. h is that rank number of item(s) which, sorted by citations, at least have received h citations over a given period of time h = 20: 20 items have received ≥ 20 cits 2011

  3. G-index – etc. • Egghe'sg-index Proposed by Leo Egghe in his paper Theory and practice of the g-index, Scientometrics, Vol. 69, No 1 (2006), pp. 131-152. • It aims to improve on the h-index by giving more weight to highly-cited articles. • Zhang's e-index published in his paper The e-index, complementing the h-index for excess citations, PLoS ONE, Vol 5, Issue 5 (May 2009), e5429. • The e-index is the (square root) of the surplus of citations in the h-set beyond h2, i.e., beyond the theoretical minimum required to obtain a h-index of 'h'. The aim of the e-index is to differentiate between scientists with similar h-indices but different citation patterns. 2011

  4. H-index … etc. • Can be demonstrated by Google Scholar or Web of Science (sort by citations) • The derivated indexes are more cumbersome to calculate in WoS 2011

  5. Ageing of journals or articles • Cited half-life - diachronic: • Acumulate citations forward in time by year: • 1990 91 92 93 94 95 96 97 98 99 00 01 02 - yrs • 2 12 20 25 30 17 12 10 0 3 10 0 - Citations • Cum:14 34 59†89106 118 128 128 131 132 • 1/2 life= 132/2 = 66 = ca. 4,2years 2011

  6. Ageing of journals or articles – 2 2011

  7. Synchronic Cited Half-life • This is shown in JCR (see earlier/next slide) • It counts citations given in present year to a journal for each year’s publications back in time! 2011

  8. JASIST 2 2010

  9. 2011

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