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Measuring Research Impact

Provides the common tools and methods to evaluate the impact of research

What is Scopus "Compare Sources" tool?

Scopus is a large abstract and citation database covering more than 15,000 peer-reviewed journals from over 4,000 international publishers. It contains scientific, technical, medical and social sciences literature, and has recently also included literature in the arts and humanities fields.

Scopus also offers tools to track, analyze and visualize research. One of them is the "Compare sources" tool, which provides quick and easy view of journal performance. It allows you to compare up to 10 journals. Full citation data are available from 1996 and are updated every two months.

How to access Scopus "Compare Sources" tool?

Access Scopus

logging in Scopus, select "Compare Sources". You will then see the "Compare Sources" page.

How to find citation data of journals using Scopus "Compare Sources" tool?

Search for a journal by title, ISSN or publisher. You can also limit your search by subject area.

From the result list, select your desired journal(s) to add it to chart on the right for comparison. Up to 10 journals can be added.

You can then evaluate journals using various journal parameters, including the three journal ranking metrics "CiteScore", "SJR" and "SNIP".

To view a list of journal titles in Scopus, access the “Browse Sources” page. Note that top journals cannot be identified within a specific subject field using Scopus. Refer to the “Finding journal publications in Scopus” box on this page for more.

What are SJR, SNIP, CiteScore and other parameters?

The journal impact values in Scopus are calculated based on 3 years' citation data. Since full citation data are available from 1996 and the citation information for articles published prior to 1996 is not available, the first journal impact values are available in 1999.

CiteScore, SJR and SNIP are the journal impact matrics used in Scopus. IPP (Impact Per Publication) is no longer used and has been replaced by CiteScore since Dec 2016.

      

SJR (SCImago Journal Rank):

SJR is also called the "prestige" metrics, because in addition to the number of citations that a journal attracts, this metric also considers the prestige/quality of the citing journal.

Note that the prestige/quality of a citing journal is determined by the number of citations to this journal. Thus the calculation of SJR is an iterative process.

SJR also addresses different citation behavior in different subject fields by allowing journal's prestige to be shared equally between its citations. An arts and humanities journal with fewer citations, for example, has higher value for each of its citations. A science and engineering journal with more citations has lower value for each of its citations.

 

SNIP (Source Normalized Impact per Paper):

SNIP measures the contextual citation impact by weighting citations based on the total number of citations in a subject field. It considers the citation potential (i.e. the likelihood of being cited) in a journal's subject field - including citing frequency, immediacy, database coverage.

A life sciences journal tends to have higher citation count, but at the same time higher citation potential. On the other hand, an arts & humanities journal is likely to have lower citation count and also lower citation potential. Because of this, the citation impact can be normalized, and direct comparison of journals across subject disciplines is therefore possible.

Each citation to a journal is weighted depending on the prestige of the source it comes from. A citation by a journal with a high prestige is valued highly, while a citation by a less influential journal is worth less. 

 

CiteScore metrics:

CiteScore measures the citations received in the reference year to the documents published in the 3-year citation period divided by the number of documents published in those 3 years. Compared with IPP (no longer used in Scopus) that includes only scholarly papers, CiteSources is more transparent by including all sources.

The calculation is also similar to JCR Impact Factor. However, in JCR Impact Factor, the numerator includes citations to any type of publications (including editorials), while the denominator includes only publications of selected document types. CiteScore, on the other hand, includes all document types both in the citation count in the numerator and in the publication count in the denominator. This provides a fair impact measurement of the journal and diminishes the chance of manipulation.

Unlike SJR, CiteScore does not consider the quality of citing journals. Unlike SNIP, CiteScore is not normalized for the subject field. 

 

Other journal parameters:

  • Citations - The number of times a source has been cited in a year
  • Docs - Total number of articles published in a year
  • Percent Not Cited - Percentage of documents not cited in a year
  • Percent Reviews - Percentage of review articles published in a year

 

Refer to the quick links on this page in the "Scopus search guides & tutorial" box on the right to access the search guides and tutorial and learn more about these metrics.

Finding journal publications in Scopus

You can also view journal sources by subject area or search for an individual journal title in Scopus. Click "Source" to search for a source or to browse the sources.

After selecting your option or performing your search, click on a journal title to view the journal's details page, from where you can view the CiteScore, SJR & SNIP metrics, or access the "Compare Sources" tool.

Within a subject area (from "Browse sources"), if you select "All", you will see a list of all the journal publications. You can sort the whole list of journal titles in a subject area by impact values and identify high impact journals within a subject discipline in Scopus. If you only want to refer to SJR, an alternative way is to use the SJR SCImago Journal & Country Rank, a free database containing SJR values derived from citation data in the Scopus database. There are even more subject categories available in this free website than in the Scopus database. Refer to the "Other free journal ranking tools" page of this guide for details.

How to best use CiteScore, SJR & SNIP?

Scopus is a larger database and covers more Asian and humanities journals than Web of Science. If your desired journal does not have JCR Impact Factor, you can try to find whether it has SJR & SNIP in Scopus.

"Compare Journals" allows you to compare the CiteScore, SJR & SNIP of up to 10 journals using charts.

SJR takes into consideration other factors than just the number of cites – e.g. quality of citing journals; different citation behavior in different disciplines, self-citations (limits to the max. of 33%). It addresses the limitations and bias perceived with JCR Impact Factor.

CiteScore is similar to JCR Impact Factor but covers 3 years and excludes citations to editorials.

Comparing the Impact Factors of journals across disciplines is extremely misleading because a top journal in the humanities field may have a much lower Impact Factor than a top journal in the science and engineering field. SNIP solves this problem because it allows direct comparison of journals across disciplines. The differences of journals’ SNIP are due to the quality of the journals but not the different citation behavior between subject fields.

Scopus search guides & tutorial

    

Search guide 

Tutorial