CWTS Journal Indicators

[Loet Leydesdorff]

> This is now the forth proposition for such an indicator, after the
Journal Impact Factor, the Scimago indicator, and the Eigenfactor. In this
context, allowing both practitioners and users to decide which one seems to
have the greatest scientific merit is essential.

Dear Eric,

If one has a parameter space, the number of options growths rapidly.
Without wishing doubt for a moment the good intentions of the developers of
the indicators, it seems to me that to leave it to users to make the
choices is a poor option.

The IF is transparent; it is a kind of two-year moving average and
everybody can reproduce it after collecting the data. The Eigenfactor,
however, looks like the value on the first eigenvector (eigenvector
centrality), but it is not precisely that. It seems irreproduceable to me
for a user or other members of the community. The SJR is derived from
PageRank but with modification so that nobody is able to reproduce it using
standard software. SNIP is hometrade of CWTS/Elsevier. See my recent letter
in JoI about the "revised SNIP". This is becoming fully intransparent while
there are clear network measures such as indegree, PageRank, etc. [For an
overview, see: How are new citation-based journal indicators adding to the
bibliometric toolbox?<http://www.leydesdorff.net/journal_indicators/index.htm>,
Journal of the American Society for Information Science and Technology 60(7)
(2009) 1327-1336;
<pdf-version<http://www.leydesdorff.net/journal_indicators/journal%20indicators.pdf>
>].

In my opinion, one should avoid central tendency statistics in the case of
these highly-skewed distributions. Lutz and I argued for integration of
citation curves after normalization in terms of percentiles (Integrated
Impact Indicator, I3). SNIP elaborates on fractional counting and thus
helps to solve normalization issues. SJR is non-parametric. These are
advantages. A user may be inclined to resort to using the h-index (in
addition to JIF) because of its simplicity.

Best,
Loet



On Wed, Sep 25, 2013 at 6:18 PM, Éric Archambault <
eric.archambault at science-metrix.com> wrote:

> Adminstrative info for SIGMETRICS (for example unsubscribe):
> http://web.utk.edu/~gwhitney/sigmetrics.html
>
> Dear Nees Jan****
>
> ** **
>
> Thank you for this addition to the growing list of journal indicators.
> Having a publicly accessible list of scores like this is really important
> and will play an important role in the debate on journal impact. Having
> rigorous researchers such as the ones at CWTS pursuing this project
> initiated by Michel Zitt and Henry Small and pursued by Moed is certainly
> useful. ****
>
> ** **
>
> However, I feel this is still at the stage of a research project and we
> should be careful to characterize our indicators carefully before telling
> the wider community that they are ready for prime time. We can’t afford to
> have any more flaky journal impact indicators. This is now the forth
> proposition for such an indicator, after the Journal Impact Factor, the
> Scimago indicator, and the Eigenfactor. In this context, allowing both
> practitioners and users to decide which one seems to have the greatest
> scientific merit is essential. This requires that the methods and all
> ingredients be known to users and practitioners. Your paper is useful to
> understand the recipe but some ingredients are missing from the public
> disclosure and these need to be made public to help the community
> characterize your tool.****
>
> ** **
>
> In particular, I think a few more details on the methods would be useful
> here. Firstly, having more details about the bootsrapping method that you
> use to compute the stability intervals would be welcome. Have you written a
> paper on this technique? Secondly, an additional column with the field of
> each journal would be more transparent and useful to users. ****
>
> ** **
>
> Do you have an explanation for this behavior:****
>
> The Journal of Engineering Education is one of the source journals with
> the highest SNIP in 2008. Is this an artifact or in 2008 the journal became
> that good compared to 2007? I find the jump surprising as it is outside the
> boundaries that you calculated. Of course, it is not impossible by chance
> to fall outside these, just that the jump is somewhat large.****
>
> ** **
>
> Kind regards****
>
> ** **
>
> Eric****
>
> ** **
>
> Source title****
>
> Source type****
>
> Print ISSN****
>
> Year****
>
> P****
>
> SNIP****
>
> SNIP (lower bound)****
>
> SNIP (upper bound)****
>
> % self cit****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2002****
>
> 207****
>
> 7.901979****
>
> 6.625****
>
> 9.355****
>
> 16%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2003****
>
> 215****
>
> 6.587213****
>
> 5.393****
>
> 7.838****
>
> 11%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2004****
>
> 194****
>
> 9.710727****
>
> 7.719****
>
> 11.838****
>
> 9%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2005****
>
> 133****
>
> 2.498504****
>
> 1.685****
>
> 3.463****
>
> 48%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2006****
>
> 111****
>
> 4.458215****
>
> 3.042****
>
> 6.121****
>
> 16%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2007****
>
> 98****
>
> 6.650165****
>
> 4.437****
>
> 9.274****
>
> 23%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2008****
>
> 93****
>
> 20.62702****
>
> 14.286****
>
> 28.396****
>
> 10%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2009****
>
> 75****
>
> 15.92148****
>
> 12.191****
>
> 20.305****
>
> 16%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2010****
>
> 77****
>
> 16.12523****
>
> 12.181****
>
> 20.454****
>
> 14%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2011****
>
> 76****
>
> 16.1012****
>
> 11.783****
>
> 21.15****
>
> 14%****
>
> Journal of Engineering Education****
>
> Journal****
>
> 1069-4730****
>
> 2012****
>
> 90****
>
> 12.49939****
>
> 9.933****
>
> 15.098****
>
> 7%****
>
> ** **
>
> ** **
>
> *From:* ASIS&T Special Interest Group on Metrics [mailto:
> SIGMETRICS at LISTSERV.UTK.EDU] *On Behalf Of *Nees Jan van Eck
> *Sent:* September-25-13 10:09 AM
> *To:* SIGMETRICS at LISTSERV.UTK.EDU
> *Subject:* [SIGMETRICS] CWTS Journal Indicators****
>
> ** **
>
> Adminstrative info for SIGMETRICS (for example unsubscribe):
> http://web.utk.edu/~gwhitney/sigmetrics.html ****
>
> The 2012 SNIP values have been released on CWTS Journal Indicators (
> www.journalindicators.com). SNIP (source normalized impact per paper) is
> a freely available journal impact indicator that uses a source
> normalization mechanism to correct for differences in citation practices
> between fields of science. Compared with the journal impact factor, SNIP
> allows for more accurate comparisons between journals active in different
> scientific fields. SNIP is calculated by CWTS based on Elsevier’s Scopus
> database. With the release of the 2012 SNIP values, stability intervals
> have been added to CWTS Journal Indicators. These intervals indicate the
> reliability of the SNIP value of a journal. For instance, if a journal’s
> SNIP value is largely due to a single very highly cited publication, this
> is indicated by a wide stability interval. SNIP is the only freely
> available journal impact indicator that is presented with stability
> intervals.****
>
> ** **
>
> Your feedback on CWTS Journal Indicators is greatly appreciated.****
>
> ** **
>
> Best regards,****
>
> Nees Jan van Eck****
>
> ** **
>
> ========================================================****
>
> Nees Jan van Eck PhD****
>
> Researcher****
>
> Head of ICT****
>
> ** **
>
> Centre for Science and Technology Studies****
>
> Leiden University****
>
> P.O. Box 905****
>
> 2300 AX Leiden****
>
> The Netherlands****
>
> ** **
>
> Willem Einthoven Building, Room B5-35****
>
> Tel:       +31 (0)71 527 6445****
>
> Fax:       +31 (0)71 527 3911****
>
> E-mail:    ecknjpvan at cwts.leidenuniv.nl****
>
> Homepage:  www.neesjanvaneck.nl****
>
> VOSviewer: www.vosviewer.com****
>
> ========================================================****
>
> ** **
>



-- 
Professor, University of Amsterdam
Amsterdam School of Communications Research (ASCoR)
Honorary Professor, SPRU, <http://www.sussex.ac.uk/spru/>University of
Sussex; Visiting Professor, ISTIC,
<http://www.istic.ac.cn/Eng/brief_en.html>Beijing;
http://scholar.google.com/citations?user=ych9gNYAAAAJ&hl=en
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