Library Services



What are bibliometrics?

Bibliometrics, also known as citation metrics, can be used to measure and rank research impact. They can be used to evaluate the influence of a particular researcher, journal or institution.

Bibliometrics are a quantitative measure and can be contrasted with the main approach to qualitative assessment - peer review.

Measurements are calculated using the number of articles published by a particular author, group, institution, or journal, and the number of citations these articles have received.

Why use bibliometrics?

Bibliometrics can be used as an indication of the importance and impact of your work or that of a research group, department or university, and therefore of its value to the wider research community. Applications for funding, research positions or promotion may require bibliometric data. University rankings may take bibliometrics into account and they are utilised in the Research Excellence Framework (REF). Bibliometrics can be used as a tool to identify research strengths and inform decisions about future research interests. Find out more.

Is bibliometric data reliable?

Bibliometrics are a quantitative and relatively straight forward measure but there are limitations with using bibliometrics, including negative citations, differences in metrics depending on the data source, multi-author publications giving equal credit to all authors and certain metrics favouring experienced researchers over early career researchers. Find out more

What is citation searching?

Citation searching can be used as part of a literature search. Searchers will often identify relevant articles through a literature search and then look at the references cited in those articles in order to identify related research. This will often lead to the discovery of publications that have not been found during the original literature search.

Citation searching is similar, but takes the searcher forward in time by identifying articles that have cited a relevant article.

For example, if you have found an interesting article that was published in 2009, a citation search will enable you to find an articles, published between 2009 and the present day, that have cited that article.

Citation searching can:

  • Provide information on how often a single piece of research has been cited by other authors
  • Provide information on how often publications by a particular author have been cited by other authors
  • Allow links between related research publications to be traced
  • Help you to ensure that you have done a thorough search
Which databases can I use for citation searching?

The main resources for citation searching include

Read our Research Output Metrics guide to find out more.

How can I find out how often my publications have been cited?

A number of databases include journal article citation information:

You can conduct a search for a published article in any of these databases and you will be able to view a list of all the articles in the database that have cited that published article.

How do I set up a citation alert?

You can set up a citation alert in Web of Science or Scopus so that you receive a notification every time a new article that is added to the database cites your publications

What is an h-index?

An h-index is a measure of an author's impact based on the citation rates of their outputs. An h-index is calculated by establishing how many publications are attributable to an author that contain at least that same number of citations. eg. If an author has an h-index of 8, they have 8 publications that have been cited at least 8 times. Find out more.

How can I find out my h-index?

An h-index can be generated in both the Web of Science and Scopus databases. The h-index may not be the same in both databases because journal coverage differs between them. Scopus includes more titles in the calculation, for example, but the coverage does not go back as far. Find out more.

What is a Journal Impact Factor?

The Journal Impact Factor (JIF) uses citation data to assess and track the impact of a journal in relation to other journals, the impact factor is recalculated each year and is based on the mean citation rate during that year of the papers published in that journal during the previous 2 years. Find out more.

How can I find the impact factor for a particular journal?

You can find out the Journal Impact Factor for a particular journal using Journal Citation Reports (JCR). Find out more.

How can I find out which journals in my field have the highest impact factor?

You can find out the Journal Impact Factors for journals in a particular field using Journal Citation Reports (JCR). Find out more.

Should I be using Journal Impact Factors?

The Journal Impact Factor (JIF) has been criticised for not accurately reflecting the value of the work published in journals. As the measure is based on the number of citation counts received by articles in a journal it cannot be used to compare journals across disciplines and is biased towards journals that contain more heavily cited publication types, such as review articles or methods papers. It is also open to editorial manipulations. The San Francisco Declaration on Research Assessment (DORA) makes recommendations for improving the way in which the quality of research output is evaluated, including the need to eliminate the use of journal-based metrics, such as the Journal Impact Factor.

What are the alternatives to the Journal Impact Factor?

Alternative metrics available to measure the impact of a journal include:

  • Eigenfactor score - This is similar to the Journal Impact Factor, but citations are weighted, with citations from highly ranked journals making a greater impact on the final Eigenfactor score than citations from journals with lower rankings. The Eigenfactor score is based on data from the Web of Science database.
  • SCImago Journal Rank (SJR) - The SJR is very similar to the Eigenfactor score and also gives more weight to highly ranked journals. The SJR is based on data from the Scopus database.
  • SNIP (Source Normalized Impact Per Paper) - SNIP weights citations according to subject field, with higher value given to a citation if it is from a field where articles tend to be cited less frequently. SNIP is based on the Scopus database.
What are altmetrics?

Altmetrics is an emerging field which aims to measure the impact of published research on the social web. This type of measure can supplement the information gained from traditional bibliometrics. Altmetrics can also be used to gauge the impact of publications that would not be included in traditional bibliometrics, for example data sets, software, or presentations.

Altmetrics are based on social web data such as:

  • Blog cites
  • Twitter cites
  • Mendeley records
  • Online repository records
  • Article views and/or downloads
  • News or media mentions, etc.

As well as demonstrating impact, altmetrics can be used to find collaborators, or to provide evidence of engagement with the content of a publication.

Further information about altmetrics can be found on our almetrics page

Are bibliometrics used to inform the REF?

Bibliometrics were used to a certain extent to inform peer review decisions in the REF (Research Excellence Framework) 2014. They are likely to continue to be used in the REF 2020.

Find out more

What effect does open access publishing have on citation metrics?

Various studies have been carried out to determine whether open access publishing has an effect on the number of downloads or citations a piece of work receives. The results vary across discipline and throughout time. As open access publishing is a relatively new concept and it takes time to build up numbers of citations it is difficult to come up with definitive conclusions to answer this question in a general context. SPARC Europe maintains a list of studies which address the question.

We support all UCL authors with making their work open access.