Measure of the number of times an average paper in this journal is cited. Copyright Thomson Reuters.
|Year||I.F.||Chemistry, multidisciplinary||Materials science, multidisciplinary||Nanoscience & nanotechnology|
The Journal Impact Factor is published each year by Thomson Reuters. It is
a measure of the number of times an average paper in a particular journal is
cited during the preceding two years.
A = the number of times articles published in a specific journal in 2009
and 2010 were cited by journals during 2011.
B = the total number of 'citable items' published by that journal in 2009 and 2010. ('Citable items' are usually articles, reviews, proceedings, etc.; not editorials or letters-to-the-editor.)
2011 impact factor = A/B.
Actual value is intentionally only displayed for the most recent year. Earlier values are available in the Journal Citation Reports from Thomson Reuters
Journals are often ranked by Impact Factor in an appropriate Thomson Reuters subject category. As there are now two Impact Factors published – two-year and five-year Impact Factors – this rank may differ, so care is needed when assessing these ranked lists to understand which of the two metrics is being used. In addition, journals can be categorized in multiple subject categories, giving them different ranks for each subject. Consequently, a rank should always be in context to the subject category.