Aggregate Cited Half Life: An indicator of the turnover rate for a body of work on a subject
.Cited Half-Life: "The cited half-life is the number of
publication years from the current year which account for 50% of current
citations received. This figure helps you evaluate the age of the
majority of cited articles published in a journal. Each journal's cited
half-life is shown in the Journal Rankings Window. Only those journals
cited 100 times or more times have a cited half life." (Ladwig & Sommese, 2005)
Eigenfactor: "Borrowing methods from network theory, eigenfactor.org
ranks the influence of journals much as Google?s PageRank algorithm
ranks the influence of web pages. By this approach, journals are
considered to be influential if they are cited often by other
influential journals."
Google PageRank: "PageRank evaluates two things: how many
links there are to a web page from other pages, and the quality of the
linking sites.PageRank evaluates two things: how many links there are to
a web page from other pages, and the quality of the linking sites." (Cutts, 2009)
Immediacy Index: The average number of times a journal article
is cited in the year it is published. Can be useful for comparing
journals on cutting edge research
.Journal Impact Factor: The journal impact factor measures the
importance of a journal and "is a measure of the frequency with which
the 'average article' in a journal has been cited in a particular year
or period" (Thomson Reuters, 2008).
How Impact Factor is Calculated "The
annual JCR impact factor is a ratio between citations and recent
citable items published. Thus, the impact factor of a journal is
calculated by dividing the number of current year citations to the
source items published in that journal during the previous two years."
(from an essay originally published in Current Contents June 20, 1994)
Journal Self-Citation: "A self-citation is a reference to an
article from the same journal. Self-citations can make up a significant
portion of the citations a journal gives and receives each year." (Thomson Reuters, 2008)
Related Journals: Calculated using the number of citations
from the selected journal title, total number of articles in the related
journal and total number of citations from the citing journal. Uses the
number of citations from one journal to another to determine a
relationship.
Self-Citation: "The practice of self-citation can be
considered at many levels, including author self-citation, journal
self-citation, and subject category self-citation..."
Unified Impact Factor: Useful when a journal title changes
because the impact factor is generally affected for two years. You can
view title changes in Journal Citation Reports
by clicking on the Journal Title changes link on one of the following
pages: Journal Search, Journal Summary List, or Marked Journal List.