LibGuides: Research Impact: Journal Impact

What Are Journal Impact Metrics?

Journal impact metrics or Journal Impact Factors (JIFs) attempt to quantify the importance of a particular journal in its field, usually via an algorithm that considers the number of articles published per year and the number of citations to those published in that journal. They are often used to help determine where to publish.

Journals with high-impact metrics are often considered more prestigious. Along with reviewing the impact metrics, you can use Ulrich's Web and Cabell's to determine if a journal is trustworthy and where you want to publish.

Cabells Journalytics This link opens in a new window
Overviews of academic journals aimed at helping professors, graduate students, and researchers publish their manuscripts. Information includes the type of review process, acceptance rate, and the number of internal and external reviews used by the journal. The predatory reports module identifies deceptive and fraudulent journals by reviewing on a 65-point metric to flag potentially exploitative or dishonest operations.
Ulrich's Web This link opens in a new window
A directory that provides detailed information on a wide range of publications, including academic journals, open-access publications, popular magazines, newspapers, newsletters, and more from around the world. It covers all subjects and is a good tool for determining the type of content, such as if it's peer-reviewed.

Where Can I Find Journal Impact Metrics?

Derived from the Scopus database, CiteScore is a family of eight journal-level indicators that offer complementary views to analyze the publication influence of journals of interest. CiteScore metrics are available for 25,300 journals as of June 2020.

Use the Sources tab to search journals by subject area, title, publisher, or ISSN.

Scopus This link opens in a new window
Peer-reviewed articles, reviews, books, and conference proceedings in various disciplines of science, including physical and life sciences.

Citescore

Calculating the CiteScore is based on the number of citations to documents (articles, reviews, conference papers, book chapters, and data papers) by a journal over four years, divided by the number of the same document types indexed in Scopus and published in those same four years.

For example, the 2020 CiteScore counts the citations received in 2017-2020 to articles, reviews, conference papers, book chapters, and data papers published in 2017-2020, and divides this by the number of these documents published in 2017-2020.

The following metrics are complimentary to CiteScore:

CiteScore Percentile indicates the relative standing of a journal in its subject field. A 98th CiteScore Percentile means the journal is in the top 2% of its subject field. You can use this number to compare sources in different subject fields.
CiteScore Rank and Rank Out Of indicates the absolute standing of a serial in its field; for example, 14th out of 63 journals in the category.
Citations is the numerator of the CiteScore calculation.
Documents is the denominator of the CiteScore calculation.
CiteScore Tracker forecasts a source’s performance for the upcoming year. CiteScore Tracker 2020, for instance, will continue to update on a monthly basis until it is fixed as an annual score in spring 2021, when Scopus starts to provide a monthly view on CiteScore Tracker 2021.

Google Scholar Metrics provides a list of the top 100 journals in specific subject fields. The journal rankings are determined with Google's 5-year h-index metric. You can select a specific subject field by clicking on the categories drop-down menu.

Metrics Included:

The h-index of a publication is the largest number h such that at least h articles in that publication were cited at least h times each. For example, the publication below has an h-index of 6

The h-core of a publication is a set of top cited h articles from the publication. These are the articles that the h-index is based on. For example, the publication above has the h-core with three articles, those cited by 17, 9, and 6.
The h-median of a publication is the median of the citation counts in its h-core. For example, the h-median of the publication above is 9. The h-median is a measure of the distribution of citations to the articles in the h-core.

SCImago uses data from the database Scopus and focuses on a 3-year window. The metrics provided are weighted by the prestige of the journal. They also normalize for differences in citation behavior between subject fields. See a list of metrics included and a screenshot example below.

SJR Indicator - measure of scientific influence of a scholarly journal
H index - the maximum value of h where the journal has published h papers that have been cited at least h times. See a diagram example in the Google Scholar tab.
Total number of documents published in the last year
Total references in the last year
Total number of citations from the last 3 years.

Scimago screenshot

SNIP uses a 3-year window of citation data from the database Scopus. SNIP weights citations based on the number of citations in a given field. They provide the number of publications (P), average number of citations per publication (SNIP), and a reliability indicator (Stability Interval). See an example below.

SNIP screenshot