Created by Thomson Reuters, the Impact Factor is the most widely-recognized method for attempting to gauge a journal's rank/importance. It is particularly well-known in the Sciences and Social Sciences.
Informed and careful use of these impact data is essential. Users may be tempted to jump to ill-formed conclusions based on impact factor statistics unless several caveats are considered.
When considering the use of the impact factor (IF), keep these aspects in mind:
Impact factors have often been used in advancement and tenure decision-making. Many recognize that this is a coarse tool for such important decisions, and that a multitude of factors should be taken into account in these deliberations.
Using Impact Factors within a given discipline should only be done with great care, as described above. Using impact factor data to compare journals across disciplines is even more problematic. Here are some of the reasons: