Not the Open Journal of Astrophysics Impact Factor – Update

Now that we have started a new year, and a new volume of the Open Journal of Astrophysics , I thought I would give an update with some bibliometric information about the 12 papers we published in 2019.

It is still early days for aggregating citations for 2019 but, using a combination of the NASA/ADS system and the Inspire-HEP, I have been able to place a firm lower limit on the total number of citations so far for those papers of 408, giving an average citation rate per paper of 34.

These numbers are dominated by one particular paper which has 327 citations according to Inspire (see above). Excluding this paper gives an average number of citations for the remaining 11 of 7.4.

I’ll take this opportunity to re-iterate some comments about the Journal Impact Factor. When asked about this my usual response is (a) to repeat the arguments why the impact factor is daft and (b) point out that we have to have been running continuously for at least two years to have an official impact factor anyway.

For those of you who can’t be bothered to look up the definition of an impact factor , for a given year it is basically the sum of the citations for all papers published in the journal over the previous two-year period divided by the total number of papers published in that journal over the same period. It’s therefore the average citations per paper published in a two-year window. The impact factor for 2019 would be defined using data from 2017 and 2018, etc.

The impact factor is prone to the same issue as the simple average I quoted above in that citation statistics are generally heavily skewed and the average can therefore be dragged upwards by a small number of papers with lots of citations (in our case just one).

I stress again we don’t have an Impact Factor for the Open Journal. However, for reference (but obviously not direct comparison) the latest actual impact factors (2018, i.e. based on 2016 and 2017 numbers) for some leading astronomy journals are: Monthly Notices of the Royal Astronomical Society 5.23; Astrophysical Journal 5.58; and Astronomy and Astrophysics 6.21.

My main point, though, is that with so much bibliometric information available at the article level there is no reason whatsoever to pay any attention to crudely aggregated statistics at the journal level. Judge the contents, not the packaging.

 

16 Responses to “Not the Open Journal of Astrophysics Impact Factor – Update”

  1. “These numbers are dominated by one particular paper which has 327 citations”

    Is this partly due to the fact that it was put on arXiv almost 7 years ago?

  2. “one particular paper which has 327 citations according to Inspire”

    It now has 439 or 438 according to ADS (the former on the main page for the paper, the latter on the citations page). However, it still has the arXiv bibcode at ADS.

  3. So you argue that the impact factor is irrelevant, based on the fact that you are doing quite well on it?

    • The OJA is a good example of why the impact factor is not very meaningful.

    • telescoper Says:

      My point is that a simple average is not a meaningful statistical descriptor of a highly skewed distribution. Our numbers provide an illustration of that.

      P.S. We don’t have an impact factor anyway, as the post explains.

      • Exactly. Stan Asimov once said that he and his brother Isaac had written 500 books between them. πŸ™‚

      • For a similar reason, the average net worth of people in a country is not necessarily a good indicator. In a village with one billionaire, on average everyone is a multi-millionaire, but in practice they might all work for the billionaire at minimum wage.

      • Phillip Helbig Says:

        The impact factor might be of some use comparing journals to one another, though as mentioned below concentrating on just the first two years overlooks the impact of some of the most important papers in the history of science.

        Many people think that being published in a high-impact journal is good. However, I think there are studies which show that the median number of citations is higher for journals with lower (but, obviously, not extremely low) impact. So, if someone you don’t otherwise know has published in a good but not highest-profile journal, chances are that that paper will get more citations than had it been in a high-impact journal. (If that paper was the one responsible for most of the citations in the high-impact journal, then the person shouldn’t be unknown to you.)

      • telescoper Says:

        The thing that amazes me is how many papers there are in many fields that never get any citations at all!

  4. “For those of you who can’t be bothered to look up the definition of an impact factor , for a given year it is basically the sum of the citations for all papers published in the journal over the previous two-year period divided by the total number of papers published in that journal over the same period.”

    Some papers don’t get cited at all in the first two years, then get cited a lot.

    • Correction: it had one citation in each of the first two years. Now, well over 12,000. So, a journal containing only papers like this one would have an impact factor of 1. Also, each year the Nobel Prize would go to someone for a paper in this journal, and all the other authors (or, at best, all but two others) would be left out. πŸ™‚

  5. I wonder what is worse: the concept of impact factor or the concept of social-media ratio. Note the assumption that all or at least most comments are negative. O tempora o mores! Sic transit gloria mundi!

    Dum vivimus vivamus!

  6. When looking at citations for a particular author, it appear that the citation histogram at ADS has as the x axis the year of the cited paper, while Google Scholar Citations has as the x axis the year of the citing paper. Does anyone know how to get the other type of histogram at each site?

    Google Scholar Citations seems, in general, to find more citations, but not all of them are correct. Also, it seems to be impossible to get automatic changes corrected (even if one selects the option to confirm suggested changes). Does anyone know how to talk to a human at Google Scholar Citations? ADS, on the other hand, is not quite as quick and generally has fewer, but they are usually all correct, and any mistakes are dealt with quickly and professionally by the friendly staff.

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