Why you should not use the journal impact factor to evaluate research

Published on Sunday, 12 January 2014

Why the impact factor of journals should not be used for evaluating research*


Eugene Garfield [1] the founder of the Journal Impact Factor (JIF), had originally designed it as a means to help choose journals. Unfortunately, the JIF is now often used inappropriately, for example, to evaluate the influence of individual pieces of research or even the prestige of researchers.

This metric has recently come under considerable criticism owing to its inherent limitations and misuse (Brumback RA (2009). Impact factor wars: episode V - The empire strikes back - Brischoux F and Cook T (2009). Juniors seek an end to the impact factor race - Rossner M, Epps HV, and Hill E (2007). Show me the data).


Brumback RA (2009) - Impact factor wars: episode V - The empire strikes back


Download the complete article

About this Editorial.



Brischoux F and Cook T (2009) - Juniors seek an end to the impact factor race


Download the complete article

About this Viewpoint.


The impact factor of a journal is a simple average obtained by considering the number of citations that articles in the journal have received within a specific time frame (Adler R, Ewing J, Taylor P (2008) - Citation Statistics. Joint Committee on Quantitative Assessment of Research, International Mathematical Union).

A previous article The impact factor and other measures of journal prestige (see below) touched upon its calculation and features. This article delves a little deeper into the fallacies of the impact factor and points that you should consider when using it.

Download the complete article


How the JIF should be used:


How the JIF should not be used:

Below are listed some of the features and shortcomings of the JIF that should be well understood in order to prevent misuse of this metric:

These are some of the reasons you should not look at the JIF as a measure of research quality. It is important to explore other more relevant indicators for this purpose, possibly even in combination. If the JIF is used by a grant-funding body or your university, it might be a good idea to list your h index and citation counts for individual articles, in addition to the impact factors of journals in which you have published. This will help strengthen your argument on the quality and impact of your papers, regardless of the prestige of the journals you have published in.


Concluding remarks

Finally, remember that the nature of research is such that its impact may not be immediately apparent to the scientific community. Some of the most noteworthy scientific discoveries in history were recognized years later, sometimes even after the lifetime of the contributing researchers. No numerical metric can substitute actually reading a paper and/or trying to replicate an experiment to determine its true worth.


Note: The above story is reprinted from materials provided by Editage, a brand of Cactus Communications. The original article was written by Editage Team.




[1] Garfield E (2006). The history and meaning of the journal impact factor - The Journal of the American Medical Association, 295: 90-93


Download the complete article

About this Commentary.