Impact Factor of publications

Lecture by Dr. C. B. Bhatt, VGEC, Chandkheda, A-2, GTU, Chandkheda (26/11/2016 – time: 02.30 pm – 03.15 pm)

The text below is  from taken notes from the lecture.

The Impact Factor (IF)

  • It is a measure reflecting the average number of citations to articles published in science and social science journals.
  • Science Citation Index (SCI) is published by Thomson Reuters. (
  • Indexes of selected journals
    • > 8000 science journals
    • > 3000 social science journals
    • > 1800 arts and humanities journals
  • Impact factors are listed in JCR (Journal Citation Reports)
    • For reports, subscription charges are applicable
  • The Impact Factor is calculated based on a 2-year window. One year reference period and 2-year citation window
    • A / B = 2011 impact factor
    • A = indexed journals cited the number of times articles published in 209 and 2010 during 2011
    • B = the total number of “citable items” published by that journal in 2009 and 2010. (Citation items are usually articles, reviews, proceedings, or notes, not editorials or letters-to-the-editor)
    • 2011 impact factors were published in 2012; they cannot be calculated until the indexing agency has processed all of 2011 publications.
  • Criticism of impact factor
    • ISI is indexing about 13000 journals published in English language only; some disciplines are especially poorly covered
    • Short (two years) snapshot of journal
    • JCR now also include the 5-year data
    • IF is an average; not all articles are equally well-cited as it is manipulative as it includes self-citations
    • Only include “citable” articles in the denominator or the equation i.e. articles and reviews
      • Editors may skew IF by increasing the number of review articles, which bring in more citations (increasing the numerator)
      • Or by increasing the number of “news” items which are cited but not considered “citable.”

Immediacy Index

  • It is a measure of how topical and urgent work published in a scientific journal is
  • Along with the better known IF measure, it is calculated each year
  • It is calculated based on the papers published in a journal in a single calendar year.
  • Search more

Eigen Factor

  • The Eigen Factor Project is a non-commercial academic research project sponsored by the Bergstrom Lab in the Department of Biology at the University of Washington
  • As with JCR, only ISI journals are ranked
  • Uses “all” ISI data, analyzed differently
    • All cited and citing reference (so includes citations from non-ISI journals, books, dissertations and such)
  • It uses Google’s page rank algorithm
  • Looks at five-year data
  • Higher EF score is better
  • EF score sum is 100.
  • For more, refer to presentation below

Article Influence

  • It measures the average influence, per article, of the papers in a journal.
  • As such, it is comparable to Thomson Scientific’s Impact Factor
  • For more, refer to presentation below

Comments on Article Influence

  • For more, refer to presentation below

SCImago Journal Rank (SJR)

  • It is based on the Scopus citation data divided by the number of articles published by a journal over three years
  • Similar to the EF
  • Self-citations are not included
  • it ranks 3,042 institutes across the world
  • it provides 5 indicators of research performance
  • For more, refer to presentation below

Quality indices for author (Journal)


  • Proposed by JE Hirsch as an index of quantifying an individual’s scientific research output
  • It combines assessment of both quantity and quality (impact, or citations)
  • It is based on the distribution of citations received by a given researcher’s publications
  • Definition: A scientist has index h if h of his /her Np papers have at least h citations… complete it
  • Get an example of calculating the h-index
  • It is automatically calculated by
    • Web of Science
    • Scopus
    • Google Scholar


  • It is an index for quantifying scientific productivity based on publication record. It was suggested in 2006 by Leo Egghe
  • For more, refer to presentation below

H-b Index

It is an extension of h-index

Michael Banks develops it

  • For more, refer to presentation below

Creative Commons License
Impact Factor of publications by Bhasker Vijaykumar Bhatt is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. It means that you are free to use the above text and references as you wish to, after appropriate citation.

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