|Nansen, Christian -|
Submitted to: Molecular Plant Pathology
Publication Type: Other
Publication Acceptance Date: November 22, 2013
Publication Date: March 5, 2014
Citation: Nansen, C., Meikle, W.G. 2014. Journal impact factors and the influence of age and number of citations. Molecular Plant Pathology. 15(3), 223-225. DOI: 10.1111/mpp.12096 Interpretive Summary: The impact factor of a journal is a number that is used as a grade for the journal and depends on how often articles in that journal are cited. Impact factors are used as tools by researchers to help them decide where to publish, since high impact factors are desirable. However, impact factors can in turn be used to judge the success of the researchers themselves, since publications in journals with high impact factors are considered more valuable than those in journals with low impact factors, and because of that may potentially be used to drive a research agenda, since the researchers will be targeting the journals with high impact factors for publication of their research. In this paper we found that impact factors are highly correlated with variables, such as the number of citations per article and the average age of those citations, that do not have anything to do with scientific merit but do depend a lot on which discipline, such as medicine, pharmacology, agronomy or entomology, that the journal belongs to. Medical journals have high impact factors relative to entomology journals, with implications about scientific quality. Impact factors should be calculated based on data within disciplines, rather than across disciplines.
Technical Abstract: The impact factor (IF) of a scientific journal is considered a measure of how important a journal is within its discipline, and it is based on a simple relationship between the number of citations of the journal’s articles divided by the number of articles in the scientific journal (http://en.wikipedia.org/wiki/Impact_factor). Thus, a journal IF equal to 1 suggests that articles in that journal are cited, on average, one time. links between success of individual researchers and IF’s of the scientific journals chosen as outlets are quite direct and significant: 1) many universities have monetary incentives for researchers to publish in scientific journals with high IF’s; 2) IF’s of published articles play a major role in the evaluation process for job applications and promotion evaluations for academic research positions; 3) publishing in scientific journals with high IF’s may lead to invitations to, for example, join an important research committee or to become a journal editor; and 4) graduate students may chose supervisors based on their publication record, including data on IF’s. We also argue, and this is supported by various published comments (i.e. Tse 2008, Yew 2010), that the importance of IF’s has reached a point that they potentially drive the research agenda. That is, in the initial phase of a new project a researcher may select a potential publication outlet based at least in part on its IF and then work backwards from there by modifying his or her research agenda to accommodate topics frequently published in that journal. Thus with a focus on IF’s, the main objective may not necessarily be the research discovery itself but rather to get it published in a certain journal with a high IF.