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Publication Metrics

This guide provides an overview to authors on various metrics designed to measure scholarly research outputs at the author, journal, and article level.

H-index

Finding a Journal's H-index

In Google Scholar, you can find a 5-year H-index for selected journal titles in their Metrics tab.

H-index attempts to calculate productivity and citations. In the example below, you can interpret Nature's H-index of 377 as meaning they had at least 377 articles published in the last 5 years that had at least 377 citations.

Scimago Journal Rankings

The SCImago Journal & Country Rank is a freely available search tool that includes the journals indicators and citation information developed from the information contained in the Scopus database. Organized by major thematic areas, subject categories, and country, journals can be compared or analyzed separately. You can also access this data directly in the Scopus database.

In Scopus, select "Sources," in the top right corner to compare publications.

Screenshot of journals in nursing with their scimago scores

Journal Acceptance Rates

Acceptance Rates

Acceptance rates are rarely published on journal webpages themselves. Additionally, acceptance rates are not always calculated the same way.

  1. Some journals use all manuscripts received as a base for computing this rate.
  2. Other journals calculate the acceptance rate using only reviewed manuscripts, not on all manuscripts received.  

Some scholarly societies, will publish acceptance rates for all of their journals and can be found with an internet search of the name of the society and acceptance rates. CSUDH also subscribes to Cabell's Directory which includes journal analytics. These directories will provide submission guidelines and acceptance rates in those fields as reported by the editors.

As a final option, contact the editor directly for acceptance rate information.

CiteScore

CiteScore is a new journal impact and ranking metric from Elsevier. It's powered using data from Scopus and covers 22,000 journals (significantly more than Journal Impact Factor). It's also freely available to our campus. 

citescoremethods

Journal Impact Factor

The journal impact factor is a propriety metric, that measures of the frequency with which the "average article" in a journal has been cited in a particular year. It's one tool to help you evaluate a journal's relative importance, especially when you compare it to others in the same field. Impact Factors are only produced for journals indexed in Thompson Scientific's ISI Web of Science. Journal Impact Factors can be found in Journal Citation Reports, a database that CSUDH does not have access to. Individual journal webpages will often list their Impact Factor on their about pages if they have one. Additionally, CSULB has Journal Citation Reports and it may be accessed by guests in their campus library. See the resources below for other metrics of journal quality.

Over time journals have tried to game the system to increase their scores. Some journals engage in large practices of self-citation or citing a sister journal quid pro quo. You can view the list of offenders each year in the freely available JCR's notices.

How to find an Impact Factor

The newest edition of JCR is the default option and is a year behind the current calendar year as impact factors are calculated at the end of the year. Select a JCR edition (Science or Social Science) and year. Please note, some subjects like Nursing, appear under both editions. Since impact factors vary widely by discipline, it is helpful to search for a subject and gain a baseline before looking at individual journals.

Journal Citation Reports selection screen image

The default display is organized by journal rank within a category.

Clicking on a journal title will provide additional details about its metrics and how they were calculated. For example, here is an explanation of the 2014 JCR for Advances in Experimental Psychology

2014 JCR calculation screenshot

Understanding the Score

Using the example above we can interpret the impact factor of 5.318 as meaning in 2014 the average article in Advances in Experimental Psychology was cited around 5.3 times.

Looking at the rank of the journal we can see that it is counted in two psychology subject areas (Experimental and Social) and is ranked highly in both; the category of experimental psychology is larger with a total of 85 journals.

journal rank list in JCR for Advances in Experimental Psychology screenshot

Factors that Influence the Score

ISI's indexing focus: ISI skews heavily toward biomedical, engineering, and clinical science journals. While they've increased coverage in the social sciences and humanities they still tend to have fewer journals indexed there especially since these fields are also more likely to use books and other publication formats besides journals. If a journal isn't listed in ISI it doesn't mean it's of lesser quality.

Age: Impact factor is based entirely on the first few years of publication so articles that are cited steadily over a longer period of time are not factored into this calculation.

Small v. Big Journals: Large journals tend to have larger impact factors due to the volume of articles they publish. When it comes to impact factor smaller journals tend to lose out.

Rockstar articles: Since impact factor looks at the average citation, a journal that has one stand-out article cited a ton of times can skew the overall score for that year.

Size of a discipline: Some disciplines have much smaller audiences and will have relatively low impact factors. For example there are less librarians in the world that health practitioners, so library science journals tend to have lower impact factors. 

Citation stacking and title suppression:  Impact factor is a well-known metric that is used in grants, tenure decisions, and other important analysis. Over time journals have tried to game the system to increase their scores. Some journals engage in large practices of self-citation or citing a sister journal quid pro quo. You can view the list of offenders each year in JCR's notices.

Creative Commons License Some content on this guide is from Spreading Your Impact Research Guide at USC and licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. It has been adapted and added by Dana Ospina and Carolyn Caffrey.