Answered By: Van Pelt Librarian Last Updated: Aug 28, 2015 Views: 49
The journal impact factor is a measure of the frequency with which the "average article" in a journal has been cited in a particular year. The impact factor will help you evaluate a journal's relative importance, especially when you compare it to others in the same field.
For example, the 2012 impact factor is all citations to articles published in that journal during 2010/2011 divided by the number of articles published in that journal during 2010/2011.
So if there were 1000 citations for 100 articles published in a journal in 2010/2011, the impact factor would be 10. The higher the impact factor the more 'impact' the journal is considered to have in its field.
For more in-depth information about impact factor and other metrics, see the Research Impact and Citation Analysis guide.