The following tools will help you objectively evaluate and compare scholarly journals within your discipline of research. Please note that this is not an exhaustive list, just a brief introduction to some of the most popular metrics.

Impact Factor  

The Impact Factor ranks journals based on how frequently articles in your journal are cited within a given period of time.

• More highly cited journals will have a higher Impact Factor
• You can search for the Impact Factor of a particular journal by going to the Web of Knowledge link in the Quick Links menu, selecting the All Databases tab, and clicking on Journal Citation Reports(JCR)
• Once logged in to JCR, choose "Science Edition" on the left and to view by subject category or search by specific journal on the right and click Submit

Strengths:

• Oldest and most well-known ranking system for journals
• Easy to calculate and understand

Considerations:

• Only uses data from journals indexed by Thomson-Reuters
• Claims to cover over 12,000 of the highest impact journals worldwide, including Open Access journals and over 150,000 conference proceedings
• Includes citations to both peer-reviewed and non-reviewed items in the journal
• The citation patterns of different disciplines are not taken into account
• Some disciplines cite much more heavily than others, driving up the Impact Factor
• Includes citations to the journal from outside journals as well as self-citations
  • Self-citing: citations to a journal from other articles within the same journal
• The measurement is dependent on the journal's size
• Smaller or more specialized journals will tend to have smaller Impact Factors

Eigenfactor Score

The Eigenfactor Score is a weighted metric that ranks journals in a discipline by taking into account the citation frequency as well as the prestige of the journals that cited your journal of interest.

• The more frequently a journal is cited, the more prestigious it is considered
• Citations to your journal of interest from a prestigious journal will have more weight than citations from less prestigious journals
• You can search for the Eigenfactor Score of a particular journal by going to Journal Citation Reports within the Web of Knowledge
• Once logged in to JCR, choose "Science Edition" on the left and to view by subject category or search by specific journal on the right and click Submit
• The Eigenfactor Score will be displayed in the journal's record

Strengths:

• Only includes citations from outside journals in the calculations
• The size of the journal does not impact the Eigenfactor Score
• It takes into account the journals from which citations are made
• More influential journals have more weight in the calculation

Considerations:

• Only uses data from journals indexed by Thomson-Reuters
• Claims to cover over 12,000 of the highest impact journals worldwide, including Open Access journals and over 150,000 conference proceedings
• The type of publication is not taken into account
• Review articles typically receive more citations than other published items
• The citation patterns of different disciplines are not taken into account
• Some disciplines cite much more heavily than others

SCImago Journal Rank  

The SCImago Journal Rank is a weighted metric, similar to the Eigenfactor Score, that takes into account citation frequency and the prestige of the journals making the citations.

• To find the SJR, go to the SCOPUS database and click the Analytics link in the top bar to compare up to 10 individual journals
• The freely accessible website: www.SCImagojr.com contains rankings of all the journals indexed in SCOPUS and an easy interface for searching and comparing within subject categories

Strengths:

• Most self-citations are not included in the calculation
• Self-citing: citations to a journal from other articles within the same journal
• The size of the journal does not impact the SJR
• It takes into account the journals from which citations are made
• More influential journals have more weight in the calculation
• It only includes reviewed materials
  • Articles, conference proceedings, review articles

Considerations:

• Only uses journals indexed by SCOPUS
• Claims to cover 18,000 peer-reviewed journals (including 1,800 Open Access journals), 400 trade publications, 300 book series, 4.4 million conference papers from proceedings and journals, and 24.7 million patent records
• Only includes data from 1996 onward
• The citation patterns of different disciplines are not taken into account
• Some disciplines cite much more heavily than others

Google Scholar Metrics

The new Google Scholar Metrics ranks journals based on an H-Index score. The H-Index attempts to square citations, where a journal's score is when the number of citations to the journal equals the number of articles it has produced.

• To find the Scholar Metrics for a journal, go to the HHSL Homepage and choose Google Scholar from the drop-down "Quick Links" menu at the right of the page
• Once on the Google Scholars homepage, click About Google Scholarstrong> at the very bottom of the browser screen. Then click Scholar Metrics from the left-hand link list
• From here you can click the link to view the top 100 publications, and then search for particular journals using the search bar above the top of the list

Strengths:

• Google can be more comprehensive in scope than Thomson Reuters or Elsevier

Considerations:

• Google includes metadata hubs, conferences, and repositories in rankings
• There's no way to tell how citations are being generated; it could be due to lots of self-citation
• Google has fairly stringent technical inclusion policies, which can lead to many good journals being exclded from inclusion due to technicalities instead of worth
• Does not account for typical citation behavior in specific fields
• Some disciplines cite much more frequently than others, which could skew the H-Index
• Depends on the specified time frame
• The value calculated for 2007-2011 could be different from the value calculated from 2005-2010
• A journal's lifetime H-Index will never decrease
• Once a journal publishes twelve papers with 12+ citations, no matter how many more papers are published, the H-Index can only increase

Faculty of 1000  

Faculty of 1000 is comprised of 10,000 peer-nominated experts who read, review, and rank published research in the biomedical and medical sciences.

• The top ranking an article receives by an evaluator is added to a factor assigned to each of the next evaluator rankings
   - Rankings of 6 would become a 1, a ranking of 8 would become a 2, and a rank of 10 would become a 3
   - Thus, if an article is read by 4 faculty who assign scores of 8, 6, 6, and 10, the FFa would equal 10 + 2 + 1 + 1 = 14

Strengths:

• Easily identify the top researchers in the biomedical and medical disciplines
• Discover the most influential articles in your research discipline
• Uncover the emerging trends and topics in research

Considerations:

• Unclear if there is a time-limit for submitting reviews on a specific article
• Usually only recently published articles are included, but there’s no rule against submitting older articles for review
• You might miss some important/interesting articles simply because they have not been chosen to be read by the faculty

More Information

If you are interested in learning more about the above journal metrics, or how to find and use them, the following resources may help.

• Which Metrics Best Answer My Question? - A brief handout providing examples of metrics to use for common questions about journals and publishing
• Journal Citation Reports Tutorial - A tutorial about Impact Factors and how to find and interpret them using Journal Citation Reports
• Eigenfactor: Detailed Methods - An article by the creators of the Eigenfactor Score detailing the mathematical theory and formulas behind the metric
• Eigenfactor.org - The main website for the Eigenfactor Score
• About Scholar Metrics - Google's information page on Scholar Metrics and how they are calculated.
• JournalMetrics.com - A website about the SJR metric and some other journal metrics that use data from the SCOPUS database
• About F1000 - A webpage explaining the birth and realization of Faculty of 1000, including how the metric is calculated