World Cup of Impact Factors

The Journal Citation Reports (JCR) for 2009 were published this week. To the constant chagrin of many scientists, these are outdated even as they are made public (for example, the Impact Factors for 2009 were just published in the middle of 2010), and there is an ongoing debate about whether they accurately represent the actual impact of journals. Still, for better or worse, they are the main way in which journal quality is judged. Competition among journals is often fierce, even to the point of skewing their editorial practices in order to improve their impact factors. Nature and Science, the two most influential journals, have a spirited rivalry over top spot, described with humour last year in PHD Comics (part 1 and part 2).

So how did journals do in this "World Cup of Impact Factors"? I selected a few journals that I find interesting.

Journal	Impact factor 2009	Impact factor 2008	5-year impact factor
Nature	34.480	31.434	32.906
Science	29.747	28.103	31.052
Nature Biotechnology	29.495	22.297	27.62
Molecular Systems Biology	12.125	12.243	13.933
PNAS USA	9.432	9.380	10.312
Nucleic Acids Research	7.479	6.878	7.279
PLoS Comput. Biology	5.759	5.895	6.429
Bioinformatics	4.926	4.328	6.271
Metabolic Engineering	4.725	4.144	4.111
PLoS ONE	4.351	-	4.383
BMC Systems Biology	4.064	3.706	4.064
FEBS Letters	3.451	3.261	3.319
BMC Bioinformatics	3.428	3.781	4.108
FEBS Journal	3.042	3.421	3.276
J Theoretical Biology	2.574	2.454	2.738
IET Systems Biology	2.384	2.143	2.397
J Mathematical Biology	1.695	1.577	1.912
J Computational Biology	1.694	1.563	2.373

Information about all journals can be accessed online on the ISI website, but a subscription is required. Accessing the website through a university IP address will usually do the trick.

UPDATE: I would be remiss not to mention Duncan's "Impact Factor Boxing" article from last year, which was a large influence for this post.


Have I left some interesting journals out of my table? Drop me a line and I will be happy to add any suggestions.