I promised a week ago I would make a comment about the ISI impact factor (IF) system (and my dislike of it).
I’ll start off my diatribe by referring everyone to an Editorial written by Mike Rissner, Heather Van Epps and Emma Hill called “Show me the data” which appeared in the Journal of Cell Biology on December 17, 2007 (technically, Vol. 179, No. 6, pg 1091-1092 of JCB). This Editorial summarizes several other important articles (which it references), namely one article that was published in the Chronicle of Higher Education and one that was published in PLoS Med.
This is much more than an editorial, I would go as far as to call it an investigatory piece. They contact Thompson, request the data used to calculate the IFs for specific journals, calculate the IFs, and compare numbers. The IF numbers don’t match. They re-contact Thompson, get a “squirrelly” answer at best, get a different set of data, re-calculate the IF’s, and get a different set of IFs. They still don’t match.
As the editorial (correctly) pointed out, if this happened in academia – the paper would be retracted. However, in this case, these numbers aren’t retracted. On the contrary, these numbers are used to determine important things like tenure and promotion.
I could go on and on, but I’ll stop here. You can read the Editorial. Thompson issued a statement (which they edited on 6/28/2008 by the way – 1.5 yrs after the original Editorial). It is located here: http://forums.thomsonscientific.com/ts/blog/article?message.uid=717
On the bright side, an alternative to ISI is on the horizon. It is free, and it was announced about 1 month after the JCB editorial. Nature wrote an article about it, which is located here: http://www.nature.com/news/2008/080102/full/451006a.html The database is located here: http://www.scimagojr.com/
And it is free (yes, I’ll say it again). So no subscription needed – unlike ISI.
Anyway, enough for today.
(And I have no affiliation with either ISI or Scimago – though I wish I did have an affiliation with Scimago because I’m guessing they will get bought by google sometime soon, if they haven’t already).