Skip to Main Content

Medicine & Health Sciences: Bibliometrics

Introduction to Bibliometrics / Citation Analysis

Bibliometrics refers to the quantitative measures used to assess research output, in other words, publication and citation data analysis. Citation analysis is based on the premise that if an academic shows good citation metrics, it is very likely that he or she has made a significant impact on the field. However, it is important to note that the reverse is not necessarily true. If an academic shows weak citation metrics, that researcher may be publishing:

  • Mainly in books
  • In a language other than English
  • In a small field or in a field not prioritised by the providers of the bibliometric data.

The three main tools for performing a citation analysis are Web of Science, Scopus and Google Scholar/Publish or Perish.

Performing Citation Analyses

When undertaking a Citation Analysis it is important to be aware of the following points.

  • Citation databases index only a limited number of peer-reviewed journal titles. They exclude many books and conference proceedings and many articles published in a language other than English.
  • It is important to choose a citation tool that is relevant to your discipline e.g. the Web of Science includes over 8,500 journals in its Science Citation Index but only 1,700 journals in its Arts and Humanities Citation Index.
  • Authors with the same name. It can be difficult to differentiate between two authors who share the same surname and forename or first initial of their forename.

Web of Science

The Web of Science is one of the main citation databases used to conduct citation analyses (see the library's list of databases). The Web of Science includes:

  • Science Citation Index > 8,500 journals
  • Social Science Citation Index > 3,000 journals
  • Arts & Humanities Citation Index > 1,700 journals

To view selection criteria and to request the inclusion of a journal title in Web of Science click here.

In addition, the proceedings of more than 12,000 annual conferences are included in the Web of Science Conference Proceedings Citation Index. Recently Web of Science have added a Book Citation Index which included over 52,000 books as at June 2014.

Web of Science Citation Analysis Tutorial

For help on doing a citation analysis in Web of Science (including an explanation of the h-index) see this video tutorial:

Selecting relevant Web of Science journals

This tutorial will show you how to use Web of Science to find journals that may be relevant to your research topic.


The h-index is intended to reflect ongoing impact. A h-index of x for an author signifies that the author has published x papers each of which has been cited at least x times. It is a commonly used indicator of research output which reflects both the number of publications and the distribution of citations to those publications.

A h-index of 5 for an author signifies that the author has published 5 papers each of which has been cited at least 5 times. A h index can be created for a single author or a research unit. It is important to remember that the index is only useful in comparing scientists at the same career stage and working within the same field as citation conventions differ substantially between disciplines.

h-index example


The Elsevier citation analysis tool Scopus can also be used to conduct citation analyses. Coverage in Scopus is broad but isn’t as deep as Web of Science with citation counts from 1996 to present only included. Scopus includes over 20,000 peer-reviewed journals, 390 trade publications, 370 book series and 5.5 million conference papers. In addition, Scopus has started to increase book coverage to 75,000 titles with a project completion date of 2016.

The subject areas covered by Scopus are:

  • Life Sciences (> 4,300 titles.)
  • Health Sciences (> 6,800 titles. 100% Medline coverage)
  • Physical Sciences (> 7,200 titles.)
  • Social Sciences & Humanities (> 5,300 titles.)

Scopus have produced a number of online tutorials including ones on Reviewing Documents and Author & Affiliation Searching which show you how to conduct citation analyses on groups of documents or individual authors.

Scopus Screenshot

Google Scholar / Publish or Perish

Publish or Perish is a citation analysis tool developed by Dr. Anne-Wil Harzing of the University of Melbourne which uses Google Scholar citation data. It is free for personal non-profit use and can be installed from

Google Scholar covers more books, theses, conference papers, technical reports and other academic publications than either Web of Science or Scopus. However, coverage in Google Scholar is uncontrolled and there is no definitive list of all publications that are included.

Citation analysis results from Publish or Perish favour those who have personally made their articles available online, for example through institutional or subject repositories. A new feature of Publish or Perish is that you can change the source data and use Microsoft Academic Search citation data instead of Google Scholar data.

Publish or Perish Citation Analysis Tutorial

 To do a citation analysis using Publish or Perish see this video tutorial from Purdue University Libraries. 

MyRI - Online Bibliometrics Training Tutorials


We would like to gratefully acknowledge the University of Limerick for their contributions to this guide.