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Research Impact and Citation Analysis: Researcher Impact Metrics

Author Metrics

Citation counts measure the impact of a publicaton or an author by counting the number of times either is cited by other works.

Hirsch's or h-index attempts to measure the impact of the published work of an author and is based on the set of an author's most cited papers and the number of citations received in other publications. The index can also be applied to the impact of a group of authors, such as a school or department, as well as a scholarly journal.   Hirsch, J. E. (2005). An index to quantify an individual's scientific research output. Proceedings of the National academy of Sciences of the United States of America, 102(46), 16569-16572.

Egghe's g-index - Gives more weight to highly cited articles. Egghe, L., "Theory and practice of the g-index," Scientometrics, Vol. 69, No 1 (2006), pp. 131-152.

Zhang's e-index - 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' and seeks to differentiate between scientists with similar h-indices.Chun-Ting Zhang, The e-index, complementing the h-index for excess citations," PLoS ONE, Vol 5, Issue 5 (May 2009), e5429. 

M-Quotient - In order to better compare academics with different lengths of academic careers, M represents the h-index divided by the number of years an academic has been active.  (Hirsch, 2005).

Contemporary h-Index- Gives more weight to recent articles.   Antonis Sidiropoulos, Dimitrios Katsaros, Yannis Manolopoulos, Generalized h-index for Disclosing Latent Facts in Citation Networks,""

Individual h-index - divides the standard h-index by the average number of authors in the articles that contribute to the h-index, in order to reduce the effects of co-authorship.  Batista, P. D., Campiteli, M. G., & Kinouchi, O. (2006). Is it possible to compare researchers with different scientific interests?. Scientometrics, 68(1), 179-189.



Citation Counts and Author Metrics

Use Scopus  and  Web of Science to find:

  • citation counts for an publication
  • who has cited a publication
  • most highly cited article for an author
  • h-index number for an author
  • eliminate self-citations from a citation count

Google Metrics

Google Scholar Metrics  - Provides these analytics for a publication: h-index, h-core, h-median, as well as those figures for the last 5 completed calendar years (h5-index, h5-core, and h5-median)

Google Scholar Citations - Free service that allows authors to check who is citing publications, graph citations over time, and compute citation metrics such as h-index and i10-index.

Publish or Perish (PoP)

Harzing Publish or Perish - This free downloadable tool uses Google Scholar data to create citation analysis reports by author or journal name.  See accompanying book.  Provides:

  • Total number of papers and total number of citations
  • Average citations per paper, citations per author, papers per author, and citations per year
  • Hirsch's h-index and related parameters
  • Egghe's g-index
  • The contemporary h-index
  • Three variations of individual h-indices
  • The average annual increase in the individual h-index
  • The age-weighted citation rate
  • An analysis of the number of authors per paper.

Unique Researcher IDs

ORCID is an open, non-profit, community-driven effort to create and maintain a registry of unique researcher identifiers and an easy method of linking research activities and outputs to these identifiers. The ORCID Registry is available free of charge to individuals, who may obtain an ORCID identifier, manage their record of activities, and search for others in the Registry.  Some online service, including Scopus, Thomson Reuters, and Figshare, have created tools for exporting and importing data to and from ORCID.   Can link to other identifiers (Scopus, ResearcherID, LinkedIn).

ResearcherID (Thomas Reuters) - Researchers can register for a unique ResearcherID and then link papers in Web of Science.  Publications can also be added using EndNote Web or by uploading RIS file.  ResearcherID can calculate the citation data only from the Web of Science databases:citation metrics will not be transferred from other databases and the H-index is based only on the data from WOS. ResearcherID is ORCID compliant, allowing users to associate publications from Web of Science to ORCID profiles. Privacy settings are controlled by the individual.


    PLOS Public Library of Science was one of the earliest publishers to offer Article Level Metrics (ALMs) on all articles.

    Metrics cover these categories: viewed, cited, saved, discussed, recommended


    Faculty of 1000

    Faculty of 1000 Prime - is composed of 5,000 Faculty Members — senior scientists and leading experts in all areas of biology and medicine — plus their associates. The Faculty recommends the most important articles, rating them and providing short explanations for their selections.