Bibliometrics is the quantitative analysis of research literature, based upon citations, and can be used to evaluate the impact on the academic community of a research paper, an individual researcher, a research group or institution, or a journal.
The most commonly used bibliometric indicators include journal metrics and researcher metrics and alternative metrics are now increasingly being used.
A researcher has index h if h of his or her Np papers have at least h citations each and the other (Np – h) papers have ≤h citations each.[1]
(Np = number of papers)
E.g. an h-index of 20 means there are 20 published papers each with at least 20 citations.
Some of the limitations of the h-index include:
There will also be variations in the h-index according to the bibliographic source or the search engine used to calculate it as the sources will only gather information from the journals they index. For example Web of Science indexes over 12,000 journals and conference proceedings and Scopus indexes over 20,000 journals and conference papers, and citation data is primarily from 1996 onwards.
You can calculate your h-index on Scopus, Web of Science and Google Scholar Citations.
Google Scholar Citations is a free service provided by Google which collates your work into one profile. The profile can be kept private or made public. The benefits of using Google Scholar Citations include a simple graphic to identify what your h-index is.
Publish or Perish retrieves and analyses academic citations to measure performance of individuals. It uses Google Scholar raw citations, then analyses and presents results according to indicators such as the h-index.
Citation counts alone should not be used as the only measure of research quality. Different sources can produce different figures, and data should be used with caution, especially if comparing across disciplines.
[1] 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. http://doi.org/10.1073/pnas.0507655102
Some of the limitations of altmetrics include:
Some alternative metric tools:
Altmetrics serve as a supplement to traditional metrics. It is always a good idea to use a range of metrics appropriate to your discipline and relevant to the context in which they are being used.