Other metrics

Several metrics other than the impact factor are available in Journal Citation Reports.

• 5-Year Impact Factor

This is a variation of the impact factor that is calculated based on citation data for the preceding five years, instead of the preceding two years.
It is suitable for journals in fields with a long period from publication to citation.

• Immediacy Index (See also "Immediacy Index" in "Help" of InCites）

This is a metric that is calculated as the average number of citations the articles in a journal received in a given year.
It is useful for comparing journals in cutting-edge fields.

• Eigenfactor Score (Reference: About the Eigenfactor® Project）

  This is a metric that is weighted so that its value becomes higher for journals that receive larger numbers of citations than those that receive smaller numbers. The idea is to make up for the shortcoming that the impact factor tends to be higher for journals that carry fewer articles.

Caveat

(See also "The Clarivate Analytics Impact Factor"）

☆Unsuitable for comparison between journals of different fields

Determining the impact factor involves various factors such as the researcher population and citation trends in each field, and citations, if any, from other fields. For this reason, comparison in terms of the impact factor is meaningless between journals in fields that significantly differ in citation practices (in terms of the average number of citations, the relationship between the time after publication and the number of citations received, among other factors). In its formal Q&A, Clarivate Analytics recommends such means as comparison in terms of the number of citations made to, and the number of citations received from, highly ranked journals in the same field.

☆Not designed to evaluate articles or researchers

Remember that the impact factor is given to journals. It does not necessarily provide an accurate representation of the citation status of individual articles. The risk of repurposing the impact factor of a given journal to evaluate articles in that journal is detailed in “Citation Statistics,” a report by the joint committee of the International Mathematical Union (IMU), the International Council of Industrial and Applied Mathematics (ICIAM), and the Institute of Mathematical Statistics (IMS). This report is translated into Japanese by the Mathematical Society of Japan. The research performance analysis tool “InCites” is useful for evaluating individual articles and researchers.

☆Caution needed for the impact factor of small-scale academic journals

By the very nature of its calculation method, the impact factor value may vary greatly by chance for small-scale journals. As far as small-scale academic journals are concerned, check the impact factor not only for a given year but also for several years preceding it.

☆Unable to represent other aspects than the number of citations

Keep in mind that the impact factor is a metric based on the number of citations. It does not represent such aspects as the trends in articles published in a given journal, the detailed field of that journal, and what kind of journals have made many citations.

Check impact factors with Journal Citation Reports

Journal Citation Reports provides various ways to check and compare impact factors. (See also the Journal Citation Reports: Learn the Basics)

List of journals

From the website, select “Browse Journal” to show a list of journals in terms of title, impact factor, and other items. Click the “Filter” button on the left to sort journals by impact factor, the total number of citations received, etc. and to specify journals by title and category.

The list can be filtered by category, publishers, open access status, and others.

Described below are the features that were available in Journal Citation Reports(Classic), a former version of the interface.

These include features that are noted as “COMING SOON” in the new interface as of August 11, 2021.
(The former version of the interface will remain accessible until the end of 2021, according to Clarivate’s press release titled “Clarivate Releases Journal Citation Reports, Naming the World’s Leading Journals.”)

Additional information

User Guide for Clarivate Analytics Products

https://clarivate.jp/training/web-of-science/
The section on the impact factor – journal metric, Journal Citation Reports in this page provides operational descriptions.

FAQ on the impact factor

https://clarivate.jp/products/journal-citation-reports/impact-factor/
This page provides an overview of the impact factor as well as frequently asked questions on how to use it.

A guidance movie in the learning portal of Clarivate Analytics

https://clarivate.com/webofsciencegroup/support/support-jcr/

【Contact】 University Library Academic Information Support Division (jsa [at] lib.hokudai.ac.jp)