Research Guides: Research Impact Metrics: Citation Analysis: Journal Citation Report

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Introduction to Journal Citation Reports

Journal Citation Reports (JCR) is a produced by Clarivate Analytics and can be accessed either by a direct link to the database from Library Search or from within the Web of Science interface.

Journal Citation Reports has a long history of analyzing, comparing and ranking journals in specific disciplines. JCR is a trusted source for finding journal ranking but it does not cover all journals.

Definitions of measurements used by JCR:

Impact Factor
A journal impact factor is a calculation based on a two-year period and is calculated by dividing the number of citations in the JCR year by the total number of articles published in the two previous years. An impact factor of 2 means that, on average, the articles published one or two years ago have been cited two times.
5-Year Impact Factor
The 5-year journal impact factor is the average number of times articles from a journal published in the past five years have been cited in the chosen JCR year.
Immediacy Index
The immediacy index is the average number of times an article is cited in the year it is published. It is a way of determining the "hot topics" in a discipline.
EigenFactor
The Eigenfactor Score calculation is based on the number of times articles from the journal published in the past five years have been cited in the JCR year, but it also considers which journals have contributed these citations so that highly cited journals will influence the network more than lesser cited journals. References from one article in a journal to another article from the same journal are removed, so that Eigenfactor Scores are not influenced by journal self-citation.
Cited Half-Life
The citing half-life is the average age of articles cited by the journal in the JCR year. For example, in JCR 2014, the journal International Social Work has a citing half-life of 7.1. That means that 50% of all articles cited by articles in International Social Work in 2014 were published between 1995 and 2014 (inclusive). This helps to evaluate the currency of the research cited.
Article Influence Score
This score is a means of measuring the influence of a journal's articles over the first five years since publication. It is calculated by multiplying the Eigenfactor Score by 0.01 and dividing that by the number of articles in the journal.