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Journal impact factors

Impact factors can be measured in terms of individual journal title and individual authors. These measures are sometimes referred to as bibliometrics. The Library holds a Library Training Courses to researchers.

Journal impact factors intend to measure the relative impact of individual journal titles. They were devised by Eugene Garfield and use the data collected by Web of Science.

Journal Citation Reports

Journal Citation Reports (JCR) data is separated into two fields, science and social sciences. The data will enable you to compare journals, demonstrating, amongst others, the most frequently cited journal in a field and the highest impact journal. Data is published annually for the previous year. E.g. 2007 data is available mid 2008.


The JCR recorded training is also available in French, Spanish and Portuguese.

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Publish or Perish

Publish or Perish is a free software programme that uses Google Scholar as the source for its raw data. It then analyses and presents data in a number of different formats using a number of different metrics.


Eigenfactor claims to rank journals in a similar way to Google ranking websites. As well as comparing citation information, the service provides information regarding the cost of journals. It also includes newpaper articles, PhD theses and popular magazines.


Scopus is a multi disciplinary database covering 14,000 titles. Scopus can be used as an indicator of the performance and impact of journals and provides two different sets of metrics to this end.


Created by Professor Henk Moed at CTWS, University of Leiden, Source-Normalized Impact per Paper (SNIP) measures contextual citation impact by weighting citations based on the total number of citations in a given subject field. The impact of a single citation is given a higher value in subject areas where citations are less likely, and vice versa.


Developed by Professor Félix de Moya, SCImago Journal Rank (SJR) is a prestige metric based on the idea that "all citations are not created equal". With SJR, the subject field, quality and reputation of the journal has a direct impact on the value of a citation. This means that a citation from a source with a relatively high SJR is worth more than a citation from a source with a lower SJR.

Sciverse Resource Library for guides and fact sheets.

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