Advantages and disadvantages of using impact factors
- Accepting that they must be used carefully and that citation patterns are specific to particular areas of research, impact factors can be a useful tool when trying to find an objective measure of quality.
- Impact factors are calculated from the number of citations received by the papers published in a named journal during the previous two years. In this way, they can reflect the changing status of a journal within a research field, as the number of citations increases or declines.
- Impact factors should not be used as a standard of comparison between disciplines. Citation practice depends very much on the subject area, with the result that a high impact factor for one discipline may look extremely low in comparison with another.
Critics point out that impact factors are calculated as an average for the total published output of a journal and that this information should not be used to gauge the importance of an individual research paper. A small number of papers published in a journal may have received a large proportion of the citations.