Journal Citation Reports (JCR) is an annual publication

Annual publication

An annual publication, more often called simply an annual, is a book or a magazine, comic book or comic strip published yearly. For example, a weekly or monthly publication may produce an Annual featuring similar materials to the regular publication....

 by the Healthcare & Science division of Thomson Reuters

Thomson Reuters

Thomson Reuters Corporation is a provider of information for the world's businesses and professionals and is created by the Thomson Corporation's purchase of Reuters Group on 17 April 2008. Thomson Reuters is headquartered at 3 Times Square, New York City, USA...

. It has been integrated with the Web of Knowledge, by Thomson Reuters, and is accessed from the Web of Science

Web of Science

ISI Web of Knowledge is an academic citation indexing and search service, which is combined with web linking and provided by Thomson Reuters. Web of Knowledge coverage encompasses the sciences, social sciences, arts and humanities. It provides bibliographic content and the tools to access, analyze,...

 to JCR Web. It provides information about academic journal

Academic journal

An academic journal is a peer-reviewed periodical in which scholarship relating to a particular academic discipline is published. Academic journals serve as forums for the introduction and presentation for scrutiny of new research, and the critique of existing research...

s in the sciences and social sciences

Social sciences

Social science is the field of study concerned with society. "Social science" is commonly used as an umbrella term to refer to a plurality of fields outside of the natural sciences usually exclusive of the administrative or managerial sciences...

, including impact factor

Impact factor

The impact factor, often abbreviated IF, is a measure reflecting the average number of citations to articles published in science and social science journals. It is frequently used as a proxy for the relative importance of a journal within its field, with journals with higher impact factors deemed...

s. It was originally published as a part of Science Citation Index

Science Citation Index

The Science Citation Index is a citation index originally produced by the Institute for Scientific Information and created by Eugene Garfield in 1960, which is now owned by Thomson Reuters. The larger version covers more than 6,500 notable and significant journals, across 150 disciplines, from ...

, and is compiled from the citation

Citation

Broadly, a citation is a reference to a published or unpublished source . More precisely, a citation is an abbreviated alphanumeric expression Broadly, a citation is a reference to a published or unpublished source (not always the original source). More precisely, a citation is an abbreviated...

 data found there.

Basic journal information

The information given for each journal includes:

• the basic bibliographic information of publisher, title abbreviation, language, ISSN
• the subject categories (there are 171 such categories in the sciences and 54 in the social sciences)

Citation information

• Basic citation data:
  • the number of articles published during that year and
  • the number of times the articles in the journal were cited during the year by later articles in itself and other journals,
• detailed tables showing
  • the number of times the articles in the journal were cited during the year by later articles in itself and other journals,
  • the number of citations made from articles published in the journal that year to it and other specific individual journals during each of the most recent ten years (the 20 journals most cited are included)
  • the number of times articles published in the journal during each of the most recent 10 years were cited by individual specific journals during the year (the twenty journals with the greatest number of citation are given)
• and several measures derived from these data:
  • the journal impact factor
    Impact factor
    The impact factor, often abbreviated IF, is a measure reflecting the average number of citations to articles published in science and social science journals. It is frequently used as a proxy for the relative importance of a journal within its field, with journals with higher impact factors deemed...
    
    , the ratio of the number of citations to the previous 2 years of the journal divided by the number of articles in those years — this is essentially the average number of recent citations per article
  • the journal immediacy index, the number of citations that year to articles published the same year,
  • the journal citing half life, the median age of the articles that were cited by the articles published in the journal that year,
  • the journal cited half life, the median age of the articles in the journal that were cited by other journals during the year.

There are separate editions for the sciences and the social sciences; the science portion includes 6166 journals, and the social science edition contains 1,768 titles. The issue for each year is published the following year, after the citations for the year have been published and the information processed.
The publication is available online (JCR on the Web), or in CD format (JCR on CD-ROM); it was originally published in print, with the detailed tables on microfiche.

Criticism

The use of these data has been subject to various criticisms, which are discussed in detail in the article on impact factor

Impact factor

The impact factor, often abbreviated IF, is a measure reflecting the average number of citations to articles published in science and social science journals. It is frequently used as a proxy for the relative importance of a journal within its field, with journals with higher impact factors deemed...

s.
The primary acknowledged limitation is that almost all the journals covered are English language

English language

English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

 journals from North America, western Europe and Australia, and that the information in the derived tables combines original research journals and review journal

Review journal

A review journal in academic publishing is a periodical or series that is devoted to the publication of review articles that summarize the progress in some particular area or topic during a preceding period.-Types:Review journals can be divided by...

s — which have very different citation behavior.