The impact factor is the average number of times articles from the journal published in the last two years have been cited in the current year. When used as a point of comparison with other journals, the impact factor indicates the relative importance of a journal within a given field. You can find journal rankings by clicking on:
Journal Citation Reports
Accessible from drop-down menu at top of Web of Science search screen. Allows you to evaluate and compare journals worldwide within subject categories.
For an explanation of impact factors, check Journal Impact Factors from Michigan State University Libraries.
Covers science and social sceinces journals (although much more in the science area, with more subject categories), including ones not included in ISI, PhD theses and more...