Impact factors are heavily criticized as measures of scientific quality. However, they still dominate every discussion about scientific excellence. They are still used to select candidates for positions as PhD student, postdoc and academic staff, to promote professors and to select grant proposals for funding. As a consequence, researchers tend to adapt their publication strategy to avoid negative impact on their careers.
The importance of high impact
Young researchers are well-advised to strive for publications in journals with high impact factors especially if they are not sure yet whether they want to pursue a career in academia or in the non-academic job market. Several funding organizations worldwide started to reduce the influence of this parameter on their strategy to fund excellent science.
One of the many critical points is that impact factors describe the average quality of a journal and should not be used for single publications.
Alternative metrics
Many alternatives for impact factors have been suggested for example the h-index (or h-factor) which are primarily based on citations and not on the impact factor of a journal where a paper is published.
Young researchers often wonder whether the impact factor or the number of citations is more relevant. This question is difficult to answer, however citations become increasingly important with increasing maturity of the career of scientists. Young researchers often have only one or two publications which are pretty new, thus, the number of citations is limited. Therefore, for pragmatic reasons, funding institutions and universities will use the impact factor of the journal as a proxy of their scientific excellence. To evaluate the output of more mature scientists the h-index or the m-index may be used which are both based exclusively on citations and not on impact factors.
Thus, young researchers are confronted with the problem that their scientific quality will be judged based on the impact factors of their publications, especially in contexts which are highly relevant for their early careers.