What is a journal impact factor? A journal impact factor measures how often articles in a journal are cited. It measures how well journals perform. The 2009 impact factor calculates how often articles published in a journal in 2007 and 2008 are cited in 2009.

How do I find the impact factor? The impact factors for journals are available on the Journal Citation Reports database. The Journal Citation Reports are a major source of citation data on journals in the areas of science and social sciences. You can search the Journal Citation Reports by specific title of a journal or by subject categories.

The Journal Citation Reports recently released the 2009 data.

If you have additional questions about impact factors or other research outputs, the Library provides detailed information on the Research Output and Impact web page.