Impact factor (FI)

Indicator that measures the frequency with which the article of a magazine has been quoted, on average, in a given year. It refers to journals and quantifies the echo that their content has in the scientific and academic world, helping to evaluate the relative importance of a magazine, especially if it is compared to others in the same scientific field.

In the Journal Citation Reports (JCR) is calculated by dividing the number of citations for the current year of articles published in the previous two years by the total number of articles published in those two years. It is calculated annually in two editions, Science and Social Sciences Edition.

Examples: to determine the impact factor of a magazine during the year 2007: 


Impact factor (Impact factor)

Thus, if a magazine has been quoted once, on average, for each published article it is necessary to understand that the impact factor will be 1. To find out if an impact factor is high or not, you must compare it with the impact factor of other magazines in the same Subject Category.

Often the validity of the impact factor as a quality index has been questioned. Some of the points to take into account in this regard are:

  • The coverage of publications by the JCR is irregular and includes few non-English language publications.
  • The comparison of impact factors between different thematic categories is not valid.
  • Some publishers encourage authors to quote articles from the same magazine they publish.
  • There is the possibility of autocit.
  • There are negative citations and these compute just like the positive ones.
  • The impact factor of a magazine can change every year.
  • The Impact Factor is not an infallible measure of quality. Some articles may receive citations years after they have been published, a fact common in some disciplines.

Last update: 09 / 03 / 2022