Impact factor trends (2012 edition)

It is that time of the year when  Impact Factor (IF) data are updated. As I finished retrieving the 2011 values (from ISI Web of Knowledge), I started looking at notable changes (upward and downward). Being a condensed matter physicist, I am focusing on those journals that are most relevant to me, but I am wondering whether similar observations to those expounded below are made in other subfields.

Let us begin, as usual, from the raw data:

Journal IF 2010 IF 2011 Difference
JLTP 1.403 1.188 -0.215
Phys. Rev. B 3.772 3.691 -0.081
J. Phys. CM 2.332 2.546 +0.214
New J. Phys. 3.849 4.177 +0.328
Phys. Rev. Lett. 7.621 7.370 -0.251
Nature Physics 18.430 18.967 +0.537
Nature 36.184 36.280 +0.096
Science 31.377 31.201 -0.176

On comparing with data from last year, the following remarks can be made:

1) Fluctuations from one year to the next can be as large as 25% of a journal’s present IF. A lot of those journals that posted seemingly significant gais last year, saw those gains almost entirely wiped out. Thus, for an Editor to make a lot of fanfare over a 10% increase on a given year, is at least imprudent. Conversely, an unexpected 10% decrease may just be a bump in the road, and should not  prompt emergency strategic meetings of editorial boards.

2) The  New Journal of Physics (NJP) outperformed its direct competition, much like it did last year, for the first time surging above the  4.0 mark. While two years in a row of solid increase are not enough to establish a trend, and therefore it is too early to tell whether the Editors of the NJP have really “cracked the IF code”, it seems to me that this is the journal to watch for, especially because it was the first to adopt a format which many believe will be eventually adopted by all science journals. At 4.177 it is already a fairly respectable publication venue. The question is, how close to 7.0 or so would it have to be, in order to be regarded as a serious alternative to Physical Review Letters (PRL) ? I think that as soon as the difference between the two is 1.5 or less, they will be considered equally prestigious by most authors.

3) If the NJP indeed continues to surge, to the point where it becomes indeed a competitor to PRL, I expect the following to happen:

  • All the existing sections of Physical Review (A, B, C, D, E, ST) are phased out. Only Physical Review X remains, accepting submissions in all areas of physics — de facto taking on the role that was once of Physical Review.
  • PRL drastically reduces the number of articles that it publishes, in an attempt to bring its IF closer to that of Nature Physics.
  • 4) Yes, I am repeating myself… so sue me, it’s Summer and blogging is slow anyway.

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    7 Responses to “Impact factor trends (2012 edition)”

    1. Camilla Says:

      ” I think that as soon as the difference between the two is 1.5 or less, they will be considered equally prestigious by most authors.”

      What if the difference is 1.55. Will the 0.05 be a mark of inequality? How did you come up with 1.5 anyhow… Please don’t tell me you just made it up.

    2. Yuan Says:

      I would like to point out that the 2011 impact factor of Nature Communications is also out. It’s 7.396 (significantly lower than Nature Physics and on par with PRL). Being a multi-disciplinary, on-line-only journal, it could be a strong competitor to PRX.

      • Massimo Says:

        Thank you for your comment. I am not sure I see Nature Communications as a competitor to PRX or even PRL due to its multidisciplinary character (read: physics is at the bottom of their priority list). I don’t see a lot of people going through the highly non-trivial and fairly time consuming exercise of formatting, rewording, restructuring the manuscript, for a journal that in the end it has the same impact factor as PRL. But hey, I may be wrong.

    3. GMP Says:

      Have you checked Nano Lett and ACS Nano? They are both relatively new, both society journals (American Chemical Society), and both with high impact factors achieved in a very short time.

      Starting from 2007, their impact factors have been:

      Nano Lett: 9.627, 10.371, 9.991, 12.219, 13.198

      ACS Nano: No IF for 2007, 5.472, 7.493, 9.865, 10.774

      Near as I can tell, they specialize in publishing on hot topics that have both scientific and technological potential, and they seem to have a strong support/respect of the nanoscience community (although I don’t know what came first — the high IF or the community support). Whatever they are doing would be worth looking into.

      • Massimo Says:

        Hey GMP, thank you for your comment. Indeed, they are reputable journals, NanoLetters seems to have started out high in the first place, ACS Nano gives me more the impression of constant, steady increase.
        I think, though, that comparing IFs across disciplines is a tricky business, often misleading. The various disciplinary communities have different sizes, different numbers of papers are published, and as a result more citations are generated. This by itself explains the high IF of Science and Nature, it is mostly arising from articles in the medical and biological fields, methink — not physics.
        Take the case of nano (whatever the !@#$ it means): you have physics, chemistry, biology, materials science, chemical engineering, electrical engineering departments with researchers working on nano-related subjects. I am curious to see what happens when the appeal of the nano fad starts waning.

        • GMP Says:

          This by itself explains the high IF of Science and Nature, it is mostly arising from articles in the medical and biological fields, methink — not physics.

          Yep, I agree. I have a Nature article that’s in cond mattter/materials science, and it gets about 13-14 citations per year, not 30 (as the IF would suggest). Other people tell me the same thing; sure, you can get a Nature/Science article that gets 100’s of citations per year, but in physics it’s not that common.

          Take the case of nano (whatever the !@#$ it means): you have physics, chemistry, biology, materials science, chemical engineering, electrical engineering departments with researchers working on nano-related subjects.

          My experience with Nano Lett (and ACS Nano) is that they publish work doesn’t really fly in PRL. Nano Lett stuff is more applied science, like cool fabrication advances or new devices. For instance, a lot of graphene transport, photonics, nanoribbon devices etc is now in Nano Lett. There is surprisingly little optoelectrinics/photonics in PRL or PRBs; they are relegated to APL/JAP it seems as too applied, but Nano Lett is not closed to this work. But you are right, it is all about nano, and nano is all the rage now, with many active people in many interdisciplinary fields. PRL sticks to publishing the best physics across the board, in all subfields, not just the hot ones.

        • Massimo Says:

          PRL sticks to publishing the best physics across the board, in all subfields, not just the hot ones.

          … and it does not publish just 200 papers a year, which makes it impossible for it to compete with journals that do, much like PRB cannot compete with PRL, IF-wise.

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