Impact Factor: Journal Citation Reports

The Journal Citation Reports (JCR) Database is used to find impact factors and more for journals.

To learn more click on this tutorial link:

http://scientific.thomson.com/tutorials/jcr4/

TIPS

Not depend solely on citation data in your journal evaluations.

Journal ranking and impact factor might be affected by: change of journal format, article type, title change and citation metrics.

To read more click on this link.
 

The aim of the JCR is to provide a systematic and objective means of determining the relative importance of science and social sciences journals within their subject categories. Information for each title includes the "impact factor" (measurement of the frequency with which the average article has been cited in a particular year) and the "immediacy index" (how quickly the average article in a journal is cited).

There are factors which can influence a journal's ranking and impact factor. Some of the factors are: changes in the journal format, title changes, cited-only journal (not covered in Thompson ISI)

The JCR can show you the:

• highest impact journals
• important journals grouped by subject
• how quickly articles in a journal are cited
• which journals cite a particular journal
• which journals are cited in a particular journal

The following Eigenfactor Score information is quoted from the Journal Citation Reports page.

Eigenfactor Metrics 

Like the Impact Factor, the Eigenfactor Score and Article Influence Score use citation data to assess and track the influence of a journal in relation to other journals. Eigenfactor Metrics are available only for JCR years 2007 and later.

You can learn more about Eigenfactor Score and Article Influence Score at www.eigenfactor.org.

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Eigenfactor Score

The Eigenfactor Score measures the number of times articles from the journal published in the past five years have been cited in the JCR year.

Like the Impact Factor, the Eigenfactor Score is essentially a ratio of number of citations to total number of articles. However, unlike the Impact Factor, the Eigenfactor Score:

• Counts citations to journals in both the sciences and social sciences.
• Eliminates self-citations. Every reference from one article in a journal to another article from the same journal is discounted.
• Weights each reference according to a stochastic measure of the amount of time researchers spend reading the journal.

Eigenfactor Score

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.