- Not all journals have impact factors. They must be indexed in Web of Science to have an impact factor, (8,000+ Science and 3,000+ Social Science journals).
- A journal has only one impact factor, but it may be listed in more than one category
- A journal impact factor should not be looked at in isolation, but in comparison to other journals in the same category
- Impact factors vary across disciplines
- A five-year impact factor may also be used in some disciplines
Impact factors can be used to:
- Help identify journals in which to publish
- Help identify journals relevant to your research
- Confirm the status of journals in which you have published
But is it a good number? To state that the British Medical Journal (BMJ) has an impact factor of 14.093 is not meaningful
It is more useful to say that BMJ’s impact factor ranks sixth of 153 journals in the field of general and internal medicine. Or to compare the journal’s impact factor of 14.093 with the aggregate impact factor for its field: 3.919
It is recommended therefore that the impact factor for a journal is not looked at in isolation. Rather, the impact factor of a journal should be compared to the impact factors of other journals within the same subject category.
Information taken from University of South Australia Subject Guide licensed under Creative Commons Share Alike 4.0