Research Impact Indicators & Metrics

What it is: 

The Journal Impact Factor is a calculation of the average citation frequency for a journal over a given period of time. It is a ratio of citations to published items. An Impact Factor is calculated by dividing the number of citations received in a given year by the number of citable items published in the preceding two years. 

What it is used for: 

The Journal Impact Factor is used to estimate the quality of a journal. A high Impact Factor within a given field is a positive indicator of quality. The Journal Impact Factor was initially developed to help librarians make collection management decisions. It has since become the most common metric to indicate journal quality. 

Nota Bene: 

Although the Impact Factor is well-known and commonly invoked, there are some characteristics that you should be note before proceeding: 

• Citation distribution within journals is highly skewed. Individual articles make uneven contributions to the overall Impact Factor of a journal, therefore should not be used as an indicator of quality at the article level. 
• Publication and citation frequencies vary by discipline, therefore Journal Impact Factors will also vary by discipline. A "good" or "bad" impact factor will depend on the context of the discipline.  
• The Impact Factor is a metric to evaluate a journal as a whole, it is not a proxy for article or author quality. 
• The Impact Factor is a proprietary metric, subject to the biases and ambiguities of the database upon which it is built.

How to find it: 

Journal Citation Report (available through the Libraries)

• The Journal Impact Factor is published annually in the Journal Citation Report (JCR). The JCR can be browsed by journal or by Web of Science category, and includes Impact Factor by year (including 2-year, 5-year and without self-citation), quartile rankings, and other citation trend data for indexed journals. The JCR coverage includes all journals indexed in the Web of Science Core Collection, although journals from the Arts and Humanities Citation Index do not meet selection criteria for the JIF.    

More: 

• A public movement against using the Impact Factor for research assessment in Declaration on Research Assessment (DORA)
• A collection of commentary in The Impact Factor and Its Discontents (LSE Blog, 2014)

What it is:

Derived from the Scopus database, CiteScore is the ratio of citations to documents published in a 4-year period to the number of documents published in the same 4-year period. It includes citations from articles, reviews, conference papers, book chapters and data sources from 28,000 active titles.

What it is used for:

Like the Journal Impact Factor, CiteScore is used to estimate the quality of a journal over time. A CiteScore rank and percentile are provided for different subject categories the journal may fall within. The higher the score and rank within a discipline, the better the perceived quality.

Nota Bene:

Note the following characteristics before proceeding: 

• Citation distribution within journals is highly skewed. Individual articles make uneven contributions to the overall score of a journal, therefore should not be used as an indicator of quality at the article level. 
• Publication and citation frequencies vary by discipline, therefore CiteScores will also vary by discipline. A "good" or "bad" impact factor will depend on the context of the discipline.  
• The CiteScore is a metric to evaluate a journal as a whole, it is not a proxy for article or author quality. 
• The CiteScore is a proprietary metric, subject to the biases and ambiguities of the database upon which it is built.

How to find it:

Scopus (available through the Libraries)

• The CiteScore can be found by searching for a journal title under "Sources" at the top of the Scopus search screen.

Cabell's Journalytics:

Cabell's Directory of Publishing Opportunities (available through the Libraries) are descriptive and evaluative metrics for 11,000 social science journals intended to help authors identify publication venues. Some of their metrics include subject area, acceptance rate, and aggregate Altmetric scores. 

Eigenfactor:

The Eigenfactor is a measure of a journal's influence similar to the Impact Factor, but weighted for the influence of the citing journal. Eigenfactor was developed in 2008 and is now included as a metric of influence in the Journal Citation Report (available through the Libraries). 

Google Scholar H5 Index:

The H5 Index is used by Google Scholar Metrics (freely available) to show the h-index of a journal for items published in the last 5 years. Google Scholar will show the top 100 journals overall and top 20 journals in selected high-level categories.  

Journal Citation Indicator: 

As a complement to their Journal Impact Factor, Clarivate Analytics introduced the Journal Citation Indicator in the 2021 Journal Citation Report (available through the Libraries). The Journal Citation Indicator is a field normalized journal-level impact metric that can be used to compare journals across disciplines. 

Scielo Analytics:

Scielo is a bibliographic database of Latin American, Spanish, and Portuguese open access scholarship. Scielo Analytics (freely available in Beta) provide metrics for all journals in their collections. Metrics include access data, publication data, and citation data such as citable items, Google h5 metrics, and citation counts received from within the Scielo network. (Note that their Analytics platform is in development so some content may not have complete metrics.)

Scimago Journal Rankings (SJR):

The Scimago Journal Ranking (freely available) is a metric similar to the Impact Factor. It is built upon the Scopus database and calculates a three year citation window, weighing citations according the prestige of the citing journal. The higher the SJR, the more prestigious the journal. 

Source Normalized Impact per Paper (SNIP):

The Source Normalized Impact per Paper (freely available) is a refinement of the Impact Factor from the Center for Science and Technology Studies at Leiden University and built upon the Scopus database that accommodates for differences in citation practices between fields. This metric allows for cross-field comparison of journals.