Citation analysis and bibliometrics
Responsible metrics - Choose your indicators with care. Don't make inappropriate comparisons.Bibliometrics can be defined as the statistical
analysis of publications. Traditionally, bibliometrics has focused on
the quantitative analysis of citations and citation counts.
Such citation analysis can be useful to researchers in:
- Helping to identify and prioritise publications to read
- Informing the choice of targets for planned publications
- Contributing to the demonstration of academic impact
- Locating potential collaborators
Bibliometric analysis can be used to help identify an institution's
research strengths, to benchmark its performance, and to inform research
strategy development. The use of bibliometrics in the assessment of
research performance is, however, not without its controversies. See
below for more on the Limitations of bibliometric analysis.
Article level metricsCitation counts are sometimes used as an indicator
of academic impact in the sense that citations from other publications
suggest that the cited work has influenced the citing work in some way.
Information on how to perform citation searches using Web of Science and
other databases is available on the Searching the literature citation searches page.
Citation rates vary widely across disciplines. If you wish to compare
citation counts from different fields you should use "normalised" or "field-weighted" citation
metrics. Scopus provides field-weighted citation impact as one of its
article metrics. It also provides Citation benchmarking data - this
shows how citations received by an article compare with the average for
similar articles. See the Scopus Article Metrics help page for more information.
Journal level metricsA range of indicators are available which aim to measure the citation
impact of journals. Such indicators may be useful if you wish to target
particular titles for planned publications.
The Journal impact factor is the most well known indicator but others
are now available which attempt to take account of variations between
subject areas and time periods.
Journal level metricsIt is also possible to use bibliometrics to calculate the impact
factors of journal titles. This can help you target highly cited
journals for your own publications.
The Journal impact factor is the most well known
indicator but others are now available which attempt to take account of
variations between subject areas and time periods.
- You can use Journal Citation Reports(JCR) to get a list of the top ranked journals in your field or check an individual journal to see its impact and rank.
- Scopus does not provide ranked lists of journals in a particular discipline, unlike JCR, but it has a good tool Compare Journals
for selecting up to 10 journals and analysing a variety of citation
parameters, including Impact per Publication (IPP) and Source Normalized
Impact per Paper (SNIP).
- SCImago, a free website, uses Scopus data to provide ranked listings of journals comparable to JCR.
- Journal Metrics,
also freely available and based on Scopus data, provides Impact per
Publication (IPP), Source Normalized Impact per Paper (SNIP) and SCImago
Journal Rank (SJR).
- Google Scholar Metrics
can be browsed to provide lists of journals by subject area ranked by
their h5-index. Alternatively, it is possible to search for the h5-index
of a specific journal.
can be problematic. It can also be difficult to establish an impact
factor for new journals.
Author (or group) level metricsThe h-index developed in 2005 by Professor Hirsch
was designed to be a simple metric with which to quantify the output of
an individual researcher. A researcher with an index of n has published n
papers, each of which has been cited n times. For example if you have
published 10 papers that have received at least 10 citations each then
your h-index is 10. Web of Science, Scopus and Google Scholar can all be
used to calculate your h-index.
Take care if you are using the h-index to make comparisons. The
h-index is only meaningful when compared to others in the same
discipline. As with all indicators, the h-index should only ever be used
alongside other forms of evaluation in performance assessment.
You, or your research group, may also wish to compare your citation
performance against that of other researchers or the normal for your
field. It is also possible to undertake an analysis of the proportion of
papers published which are amongst the most highly cited (e.g. the top
10%) in that field. See SciVal for more information.