Journal impact factor: a bumpy ride in an open space.

The journal impact factor (IF) is the leading method of scholarly assessment in today's research world. An important question is whether or not this is still a constructive method. For a specific journal, the IF is the number of citations for publications over the previous 2 years divided by the number of total citable publications in these years (the citation window). Although this simplicity works to an advantage of this method, complications arise when answers to questions such as 'What is included in the citation window' or 'What makes a good journal impact factor' contain ambiguity. In this review, we discuss whether or not the IF should still be considered the gold standard of scholarly assessment in view of the many recent changes and the emergence of new publication models. We will outline its advantages and disadvantages. The advantages of the IF include promoting the author meanwhile giving the readers a visualization of the magnitude of review. On the other hand, its disadvantages include reflecting the journal's quality more than the author's work, the fact that it cannot be compared across different research disciplines, and the struggles it faces in the world of open access. Recently, alternatives to the IF have been emerging, such as the SCImago Journal & Country Rank, the Source Normalized Impact per Paper and the Eigenfactor Score, among others. However, all alternatives proposed thus far are associated with their own limitations as well. In conclusion, although IF contains its cons, until there are better proposed alternative methods, IF remains one of the most effective methods for assessing scholarly activity. © American Federation for Medical Research 2020. No commercial re-use. See rights and permissions. Published by BMJ.