Journal impact factors are one way to evaluate the importance of a journal. It is a measure of how often articles from a particular journal are cited in other academic publications in a particular year. You should not depend entirely on the impact factor to judge the quality of a journal: citation bias occurs when authors cite their own work, review articles often generate more citations than research articles, new journals need time to develop a citation record, and different fields of research publish at different rates.
2. Select the edition and year to search. Biomedical journals will be covered in the JCR Science Edition. Some fields such as Nursing, will be covered in both the JCR Science and JCR Social Science Editions.
3. To identify the highest cited journals in a particular field choose the "View a group of journals by Subject Category" option.
4. To look up a specific journal's impact factor choose the "Search for a specific journal" option.
5. Click on the Abbreviated Journal Title to see detailed information including the Impact Factor Trend showing the impact factor over five years, and the journal's Subject Categories.
6. Because impact factors mean little on their own, you may want to see where the journal ranks with others in the same subject category. To do this click Journal Ranking on the detailed information page.