Cited Journal Data
Cited Journal data show how many citations a journal received in the JCR year. Cited journal data is relevant when analyzing metrics such as the Journal Impact Factor and Market Share. Tables on the page provide extensive data for the following:
The Cited Half-Life is the median age of the citations received by a journal during the JCR year. A citation’s age is equal to the publication year of the citing item (i.e., JCR year) minus the publication year of the cited item. By definition, half of a journal's earned citations are to items published before the Cited Half-Life, and half are to items published after the Cited Half-Life. In the example histogram, a journal received 10,500 citations during the JCR year (the JCR year is the period marked 0-1; the year prior is the period marked 1-2; and so on). The Cited Half-Life is 4.6, meaning the median age of the citations is 4.6 years old. Half of the citations are to items that are newer than 4.6 years old (orange zone), and half are to items that are older (blue zone).
For all JCR data years prior to 2017, the maximum Cited Half-Life that will be displayed in the Key Indicators table is 10 years. Any value greater than this will be displayed as >10.0.
In 2017 data and for all subsequent years, the Cited half-life metric is calculated to a resolved value. Cited half-life shows how a journal’s back-file is actively contributing to current scholarship.
|The above histogram is provided for explanatory purposes and is not available in Journal Citation Reports|
The Cited Half-Life Data table will display information beginning with the current JCR Year and extend back an additional 9 years, with further historical cited years noted in the final column. Scroll to the right to see all years.
Only journals cited 100 or more times in the JCR year have a Cited Half-Life.
A higher or lower Cited Half-Life does not imply any particular value for a journal. For instance, a primary research journal might have a longer Cited Half-Life than a journal that provides rapid communication of current information. Cited Half-Life figures may be useful to assist in collection management and archiving decisions. Dramatic changes in Cited Half-Life over time may indicate a change in a journal's format. Studying the half-life data of the journals in a comparative study may indicate differences in format and publication history.
The Cited Journal Graph shows the distribution (by cited year) of citations published in journals during the JCR year to items published in the Journal during the last 10 years.
The white/grey division indicates the Cited Half-Life (if < 10.0 years). Half of the cited articles were published more recently than the Cited Half-Life.
The two light-blue columns indicate citations used to calculate the Impact Factor (always the 2nd and 3rd columns).
The top (yellow) portion of each column indicates journal self - citations: citations from articles in the journal to articles in the same journal.
The bottom (blue) portion of each column indicates non-self-citations: citations from the journal to articles in other journals.
The Cited Journal Table lists the journals that cite the journal identified at the top of the page. In the table below, the cited journal is Molecular Cancer. The citing journals are listed in the Citing Journal column. All of the citing articles were published in 2012.
|Impact||Impact factor of the citing journal.|
|Cited Year: All Years||The total number of citations from the citing journal. This total includes the number shown under each year and the number in the Rest column.|
|Cited Year: Individual Years||
Publication year of the cited articles.
|Cited Year Rest||
All publication years of cited articles prior to the 10-year period defined by the table. For example, if the cited years shown are 2012-2003, the Rest column will show the number of citations from the citing journal in 2012 to articles published in the cited journal in 2002 and any earlier year.