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Research Guides@Tufts

Measuring Research Impact

Learn about journal metrics, author metrics and altmetrics.

How is Journal Impact Measured?

Different metrics have been developed to quantify the quality and impact of a journal.  Each metric has its strengths and weaknesses and should be used in combination with other factors when evaluating a journal.

Impact Factor, developed in the 1960s, remains a commonly used measure of journal quality.  In recent years, other metrics have been developed to compete with, and overcome the flaws of, Impact Factor.

Impact Factor, Eigenfactor, Article Influence Score

Impact Factor (IF)
  • Frequency with which the 'average article' in a journal has been cited over a defined time period
  • Number of citations in the current year to articles published in the journal in the previous n years, divided by the total number of articles published in the journal in the previous n years
  • Cannot be used to compare journals from different subject fields
  • Available in Journal Citation Reports
Eigenfactor
  • Number of times articles published in a journal over the past 5 years have been cited, with citations from more influential journals weighted more than citations from less influential journals
  • Scaled so that scores for all journals in Journal Citations Reports sum to 100; score of 1 indicates that journal has 1% of total influence of all indexed journals
  • Estimation of how often a journal will be used by scholars
  • Can be used to compare journals from different subject fields
  • Available in Journal Citation Reports and freely accessible at Eigenfactor.org
Article Influence Score
  • Average influence of each of a journal's articles over the first 5 years after publication
  • Normalized so that mean article has score of 1
  • Measure of the average influence per article for a journal
  • Can be used to compare journals from different subject fields
  • Available in Journal Citation Reports and freely accessible at Eigenfactor.org

Find Metrics in Journal Citation Reports

Find Metrics for a Single Journal
  • Enter the journal title, or title word, in the search box on the JCR homepage, choosing from the list of options that appears as you type.
  • You will be brought to the Journal Profile page, where you can view Impact Factor, Eigenfactor, Article Influence score, and other key indicators.  Scroll down the Journal Profile page to view additional information, such as rank within subject category and citing relationships to other journals.
Compare Metrics for Multiple Journals in Journal Citation Reports:
  • Choose Select Journals from the left-hand column on the JCR homepage.  Enter journal title, or title word, in the search box, choosing from the list of options that appears as you type.  Repeat for additional titles.  Once you have added the desired journals, close the box.
  • Scroll down the JCR homepage, and click submit.
  • The total number of citations, Impact Factor and Eigenfactor for each journal will be displayed.  If you wish to view other metrics, then select Customize Indicators and choose additional metrics.  Note: you must have a Thomson Reuters account to use this feature.  You can create an account at anytime.
  • To view trends over time and where journals rank in their subject categories, check the boxes next to the journals that you wish to compare and select Compare Selected Journals.
Find Metrics for a Subject Field:
  • Choose Select Categories from the left-hand column on the JCR homepage.  Check the box next to the category that you wish to view.  Close the box.
  • Scroll down, and click submit.
  • The total number of citations, Impact Factors and Eigenfactors for the journals in the chosen category will be displayed.
Export Metrics to Excel:
  • Data for a single journal or multiple journals can be exported from JCR to Excel.
  • Click the download JCR Download Icon icon at the top of each page.  Choose the desired format (CSV for Excel).

Journal Citation Reports homepage

Journal Citation Reports

CiteScore, SNIP, SCImago Journal Rank

CiteScore
  • Average number of citations per document
  • Number of citations received in the current year to documents published in the journal in the previous 3 years, divided by the total number of documents published in the journal in the previous 3 years
  • All document types included in calculation, e.g. articles, letters, editorials, conference papers
  • Cannot be used to compare journals from different subject fields
  • Available in Scopus and freely accessible at Elsevier's Journal Metrics
SCImago Journal Rank (SJR)
  • Average number of weighted citations received in a given year by articles published in the previous 3 years
  • Citations from more prestigious journals weighted more than citations from less prestigious journals
  • Can be used to compare journals from different subject fields
  • Available in Scopus, and freely accessible at Elsevier's Journal Metrics and SCImago Journal & Country Rank
Source Normalized Impact per Paper (SNIP)
  • Ratio of journal's citation count per article to citation potential of subject field
  • Single citation is given a higher value in fields where citations are less likely
  • Can be used to compare journals from different subject fields
  • Available in Scopus, and freely accessible at Elsevier's Journal Metrics and CWTS Journal Indicators

Find Metrics in Scopus

Find Metrics for a Single Journal
  • Click the Sources link at the top of the Scopus homepage.
  • Search for an individual journal title, or browse titles alphabetically or by subject category.
  • Click on the name of a title to view details about the CiteScore for that title.

Sources link on Scopus homepage

Scopus Sources