So one of the Twitts was recently describing a grant funding agency that required listing the Impact Factor of each journal in which the applicant had published.
No word on whether or not it was the IF for the year in which the paper was published, which seems most fair to me.
It also emerged that the applicant was supposed to list the Journal Impact Factor (JIF) for subdisciplines, presumably the "median impact factor" supplied by ISI. I was curious about the relative impact of listing a different ISI journal category as your primary subdiscipline of science. A sample of ones related to the drug abuse sciences would be:
Substance Abuse 2.36
Behavioral Sciences 2.56
Fascinating. What about...
Veterinary Sciences 0.81
Plant Sciences 1.37
aha, finally a sub-1.0. So I went hunting for some usual suspects mentioned, or suspected, as low-cite rate disciplines..
Geosciences, multidisc 1.33
Statistics and Probability 0.86
This a far from complete list of the ISI subdisciplines (and please recognize that many journals can be cross-listed), just a non-random walk conducted by YHN. But it suggests that range is really restricted, particularly when it comes to closely related fields, like the ones that would fall under the umbrella of substance abuse.
I say the range is restricted because as we know, when it comes to journals in the ~2-4 IF range within neuroscience (as an example), there is really very little difference in subjective quality. (Yes, this is a discussion conditioned on the JIF, deal.)
It requires, I assert, at least the JIF ~6+ range to distinguish a manuscript acceptance from the general herd below about 4.
My point here is that I am uncertain that the agency which requires listing disciplinary medians JIFs is really gaining an improved picture of the applicant. Uncertain if cross-disciplinary comparisons can be made effectively. You still need additional knowledge to understand if the person's CV is filled with Journals that are viewed as significantly better than average within the subfield. About all you can tell is that they are above or below the median.
A journal which bests the Neurosciences median by a point (3.75) really isn't all that impressive. You have to add something on the order of 3-4 IF points to make a dent. But maybe in Forestry if you get to only a 1.25 this is a smoking upgrade in the perceived awesomeness of the journal? How would one know without further information?