This one is for the impact factor geeks. The ever engaging Lou of A scientist's life has posted a graph reviewing the changes in the impact factors of Cell, Nature and Science from 1992-2006.
You'll have to click through for the full graph but gee, there was a lot of action 2000-2002 wasn't there? We don't usually think of the relative rankings as being quite so....dynamic, over such short intervals, do we? Or is that just me since I never really pay attention to trends in any serious way.
This highlights yet another absurdity in the process of judging a CV by reviewing the journals listed. I can't imagine anyone noting the publication year and mentally adjusting relative rankings by changes in absolute or relative Impact Factor. Maybe we should just go ahead and start itemizing CV entries with the appropriate IF for the relevant publication year?
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I think people understand that (1) the impact factor is only relevant as a relative measure for comparing journals and (2) only substantial differences mean anything. Science, Nature, and Cell are the top three general interest journals in the biosciences that publish original research, and it is by a pretty fair margin. I doubt anyone pops a woody when Science passes Nature or Cell passes Science or whatever.
Posted by: PhysioProf | June 4, 2008 6:45 AM
I have a colleague who does include impact factor after each of the publications in his CV for internal review. In a very broad department, it's maybe not such a bad idea. Of course, for annual reviews the IF wouldn't be released yet....
Posted by: ScienceWoman | June 4, 2008 7:34 AM
I think the declining IF of these journals is due to instantaneous access to specific journal topics of interest via online searches through sites like pubmed. Most people I know read journal articles...not entire journals.
Posted by: Craig | June 4, 2008 8:26 AM
I changed fields for my postdoc around the time Cell slid way down -- I'd thought it was getting progressively less interesting as my own interests changed, but apparently others felt the same way. Next you'll be telling me that music really as been getting worse for a decade, and that it's not just me getting old!
Beyond Craig's point, which is completely true, I think Cell's decline also reflects the maturity of genetic model systems, with the kind of step-by-step reductionism Cell loves no longer picking low-hanging fruit.
Posted by: JSinger | June 4, 2008 9:39 AM
No mystery here. Ben Lewin steps down as editor of Cell in late 1999. Cell IF tanks immediately thereafter. Lewin was famous (infamous) for ignoring the recommendations of peer reviewers and publishing whatever the hell he wanted, if he personally thought it was interesting and/or important. Ben was very good at this; peer reviewers have axes to grind with authors and suck.
Posted by: whimple | June 4, 2008 10:17 AM
I very quick glance at the Science archives shows that they added online supplemental material around the time of its impact factor increase (added around December 2000). This probably transformed Science from a GlamourMag with little reason to reference the articles to a place where research could be presented in full.
Cell isn't a research-relevant journal to me, but it seems the articles are longer and they allowed online supplemental data even further back so there wouldn't be a spike. The decline could also be based on the internet explosion since it is more gradual. The stratospheric impact factors in the early 90's can really only exist if this is the prime journal that most people read. As it become easier to read articles in other journals, that number needs to take some hit. The fact that it's now closer to Science and Nature makes sense.
Posted by: bsci | June 4, 2008 10:25 AM