Mandated and Unmandated Open Access: Comparing Green and Gold
yassinegargouri at HOTMAIL.COM
Sat Aug 28 14:27:54 EDT 2010
Jan Velterop has posted his hunch that of the overall percentage of articles
published annually today most will prove to be articles in Gold OA journals,
once one separates from the articles classified as self-archived Green OA
those self-archived articles that are also published in Gold OA journals:
aware of credible research that shows how many articles
(in the last 5 years, say), outside physics and the Arxiv preprint servers,
have been made available with OA exclusively via 'green' archiving in
repositories, and how many were made available with OA directly ('gold') by
the publishers (author-side paid or not)?
The 'gold' OA ones may of course also be available in repositories, but
shouldn't be counted for this purpose, as their OA status is not due to them
being 'green' OA.
It is my hunch (to be verified or falsified) that publishers (the 'gold'
road) have actually done more to bring OA about than repositories, even
where mandated (the 'green' road).
J. Velterop, American Scientist Open Access Forum, 25 August 2010
The results turn out to go strongly contrary to Velterops hypothesis.
Our ongoing project is comparing citation counts for mandated Green OA
articles with those for non-mandated Green OA articles, all published in
journals indexed by the Thompson/Reuters ISI database (science and
social-science/humanities). (We use only the ISI-indexed sample because the
citation counts for our comparisons between OA and non-OA are all derived
The four mandated institutions were Southampton University (ECS), Minho,
Queensland and CERN.
Out of our total set of 11,801 mandated, self-archived OA articles, we first
set aside all those (279) articles that had been published in Gold OA
journals (i.e., the journals in the DOAJ-indexed subset of ISI-indexed
journals) because we were primarily interested in testing the OA citation
advantage, which is based on comparing the citation counts of OA articles
versus non-OA articles published in the same journal and year. (This can
only be done in non-OA journals, because OA journals have no non-OA
articles.) This left only the Green OA articles published in non-Gold journals.
We then extracted, as control articles for this purely Green OA subset, 10
keyword-matched articles published in the same journal and year. The total
number of articles in this control sample for the years 2002-2008 was 41,755
(our preprint for PloS, Gargouri et al. 2010, covers a somewhat smaller,
earlier period: 2002-2006, with 20,982 control articles).
Next we used a robot to check what percentage of these control articles was
OA (freely accessible on the web).
Of our total set of 11,801 mandated, self-archived articles, 279 articles
(2.4%) had been published in the 63 Gold OA journals (2.6%) among the 2,391
journals in which the authors from our four mandated institutions had
published in 2002-2008. Both these estimates of percent Gold OA are about
half as big as the total 5% proportion for Gold OA journals among all
ISI-indexed journals (active in the past 10 years). To be conservative, we
can use the higher figure of 5% as a first estimate of the Gold OA
contribution to total OA among all ISI-indexed journals.
Now, in our sample, we find that out of the total number of articles
published in ISI-indexed journals by authors from our four mandated
institutions between 2002-2008 (11,801 articles), about 65.6% of them (7,736
articles) had indeed been made Green OA through self-archiving by their
authors, as mandated (7,457 or 63.2% Green only, and 279 or 2.4% both Green
In contrast, for our 42,395 keyword-matched, non-mandated control articles,
the percentage OA was 23.4% (21.9% Green and 1.5% Gold).
Björks et als (2010) corresponding figures for his ISI sample (1282
articles for 2008 alone, calculated in 2009), was 20.6% OA (14% Green, 6.6%
The variance is probably due to discipline blends in the samples, but
whichever sample and figures one chooses whether our 21.9% Green and 1.5%
Gold or Björks et als 14% Gold and 6.6% Green, the figures fail to bear
out Verlterops prediction that:
publishers (the 'gold' road) have actually done more to bring OA
about than repositories, even where mandated (the 'green' road).
Moreover (and this is really the most important point of all), the hunch is
the wrongest of all precisely for where OA is mandated, for there the
percent Green is over 60%, and headed toward 100%. That is the real power of
Green OA mandates.
Gargouri, Y., Hajjem, C., Lariviere, V., Gingras, Y., Brody, T., Carr, L.
and Harnad, S. (2010) Self-Selected or Mandated, Open Access Increases
Citation Impact for Higher Quality Research. PLOS ONE (under review)
Björk B-C, Welling P, Laakso M, Majlender P, Hedlund T, et al. (2010) Open
Access to the Scientific Journal Literature: Situation 2009. PLOS ONE 5(6):
e11273. http://dx.plos.org/10.1371/journal.pone.0011273 .
Subject: Current Percentage of Green and Gold OA
From: Stevan Harnad <amsciforum at GMAIL.COM>
Reply-To: ASIS&T Special Interest Group on Metrics <SIGMETRICS at LISTSERV.UTK.EDU>
Date: Wed, 25 Aug 2010 14:17:58 -0400
text/plain (51 lines)
On Wed, Aug 25, 2010 at 10:00 AM, Velterop <velterop at gmail.com> wrote:
> Is anyone on this list aware of credible research that shows how many
> articles (in the last 5 years, say), outside physics and the Arxiv
> preprint servers, have been made available with OA exclusively via
> 'green' archiving in respositories, and how many were made available
> with OA directly ('gold') by the publishers (author-side paid or not)?
> The 'gold' OA ones may of course also be available in repositories, but
> shouldn't be counted for this purpose, as their OA status is not due to
> them being 'green' OA.
The percentage of total annual journal article output that is Green OA
has been hovering at about 15% for the past half decade at least. Here
are figures for Green OA only, for a Thomson/Reuters ISI sample of
21,000 control articles. Articles in Gold OA journals were excluded
from the count: http://bit.ly/MandVSNonMand
Source: Gargouri, Y., Hajjem, C., Lariviere, V., Gingras, Y., Brody,
T., Carr, L. and Harnad, S. (2010) Self-Selected or Mandated, Open
Access Increases Citation Impact for Higher Quality Research. PLOS ONE
(under review) http://eprints.ecs.soton.ac.uk/18493/
Bo-Christer Björk's sample of 1282 Thompson/Reuters ISI articles, he
found much the same percentage Green (14%) but he also had an estimate
of Gold (6.6%). (Since ISI does not index all journals, Björk also
made an estimate for a total sample of 1837 ISI + nonISI journals, and
there the relative percentage for Gold was 8.5% and Green was 11.9%)
Source: Björk B-C, Welling P, Laakso M, Majlender P, Hedlund T, et al.
2010 Open Access to the Scientific Journal Literature: Situation 2009.
PLOS ONE 5(6): e11273. doi:10.1371/journal.pone.0011273 [Table 3]
> It is my hunch (to be verified or falsified) that
> publishers (the 'gold' road) have actually done more to bring OA about
> than repositories, even where mandated (the 'green' road).
I would say that the data above pretty definitively falsify your hunch...
(The 160 institutional and funder mandates so far have not made a
detectable dent in the c. 15% figure, though this may soon change.)
(Do you imagine, though, Jan, that the way most authors are complying
with their institution's or funder's mandate to make make their
articles OA is by publishing them in a Gold OA journal, rather than
publishing them in whatever journal they judge appropriate, and then
depositing the final draft in their OA IR, as the mandates state?)
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