The validity of the Impact Factor as a measure of journal quality (and also the quality of the articles contained therein) is increasingly being questioned. Should the academic community wean itself off this measure, essentially by paying it a lot less attention?
This article (and the discussion in the comments) captures some of the aspects of this issue quite well.
The Persistent Lure of the Impact Factor - Even for PLOS ONE
For those new to the discussion, the Impact Factor is a metric assigned to journals by Thomson Reuters. The Impact Factor of a journal for a given year is the average number of times its articles published in the preceeding two years have been cited that year. So the 2012 Impact Factor for a journal is the average number of times its 2010 and 2011 articles were cited in 2012. As it's based on citations, the Impact Factor is intended to be an indication of journal quality, and it is sometimes used to assess the quality of articles themselves (an article is published in a high impact journal, therefore it is high quality). Some of the objections to these uses are addressed in the article linked to above. It's an interesting issue and one with increasing prominence.
Journal Impact Factors can be found using Thomson Reuter's Journal Citation Reports. For more information about measuring research impact see this webpage, and feel free to get in touch.
