What is a peer-reviewed journal?1. A journal is a peer-review manager and copy-editor (the peers -- qualified, answerable specialists -- chosen by the editor, review for free; the editor adjudicates the reviews and the author revisions).
2. If the article is accepted, the accepted draft is certified with the journal's name.
3. The journal generates and distributes (3a) a print and/or (3b) online edition.
A journal that does not generate a print edition (3a) is still a journal.
A journal that does not generate an online edition (3b) is still a journal.
The journal certifies (and answers for) its content and quality standards with its name and track-record.
If the journal's costs are paid by subscriptions, it's a
subscription journal.
If costs are paid by subsidies, it's a
subsidized journal.
If costs are paid by the author, it's an
author-pays journal.
OA is
free online access to journal articles, immediately upon publication.
If OA is provided by the journal, it's
Gold OA publishing.
If OA is provided by the author, it's
Green OA self-archiving.
If the journal is OA, it's a Gold OA journal. If not, not.
There is hence no need for (nor any new information provided by) new terms like "diamond," "overlay" or "epi" journal.
An OA journal that charges neither subscriptions nor author-fees is a subsidized journal ("diamond" adds no further information or properties).
An OA journal that generates neither a print nor an online version is an OA journal that generates neither a print nor an online version:
the self-archived version is the only version.
The vast majority of free online journals (Gold OA) do not charge APCs.
It is arbitrary and unilluminating to invent a spectrum of colours or precious metals to classify their various possible cost-recovery models as if they were forms of OA.
OA is not about cost-recovery models (nor about peer-review models); it is about research access. (Don't conflate OA with publication cost-recovery models.)
The reason (some) physicists and mathematicians speak of
"overlay" journals is that many physicists and mathematicians, before submitting their papers to a journal for peer review, self-archive their unrefereed "preprints" in Arxiv. Most then also go on to self-archive their final, peer-reviewed "postprints" in
Arxiv. They think of the peer-review, copy-editing, and certification as an "overlay" on their unrefereed preprint.
But, by the same token,
the peer-review, copy-editing and certification is an "overlay" on every author's unrefereed preprint, whether the journal is print, online, both, or neither.
And most authors don't self-archive their unrefereed drafts at all.
Some fields of mathematics and physics already have close to 100% (Green) OA, by self-archiving in Arxiv.
So it looks as if
Episciences.org is just a new online journal platform -- there are
others) -- one that has neither a print edition nor an online edition. That means the self-archived version will be the version of record. (Green will become Gold.)
Submission is done by depositing the unrefereed draft in Arxiv (instead of just emailing it to the journal, or sending a URL from the author's website or institutional repository, as with most other journals, OA and non-OA, subscription-based, subsidy-based, and/or author-fee-based).
In addition, it looks as if Episciences.org is hoping to cover the costs of
1 and
2 above (peer review and certification) for its start-up mathematics journal(s) out of subsidies (from
CCSD and
Institut Fournier/Grenoble) rather than subscriptions or author fees.
3a and
3b (print and online edition) and their costs are being dropped and
access-provision and
archiving are to be offloaded onto Arxiv.
This is a very sensible idea, but it may be premature for sustainability: All other disciplines may first have to (be mandated to) provide 100% Green OA, as some subfields of maths and physics have long been doing, unmandated, and then all institutional subscription journal subscription funds will be freed to pay the remaining costs of 1 and 2 (whether via Gold OA fees or subsidies). Nor will Arxiv be the main locus of self-archiving in most other disciplines: Authors' own institutional repositories will be.
In principle it does not matter in the least whether the self-archiving is in a central repository like Arxiv or in each author's own
institutional repository, from which one or many subject repositories (and search engines) harvest, just as long as the preprints and postprints are reliably deposited and archived online. But in practice, there are many reasons why institutional and funder mandates should stipulate institutional deposit rather than institution-external deposit.
There are no new entities needing the name "epijournals" -- just journals. What is being proposed is by Episciences.org is journals with no print or online edition, in a subdomain (of mathematics and physics) where all authors already self-archive (100% Green). (
Postpublication commentary on peer-reviewed journal articles is postpublication commentary -- not
peer review.)
Let's see if subsidies work to keep episciences.org journals sustainably afloat. If not, they will of course have to convert to author fees. Either way,
it's just another (proposed) new Gold OA journal.
My own view is that it is too early to bury either the print or the online edition of subscription journals: Not while they still publish most of the top journals, and hence institutions cannot cancel them, nor can authors stop publishing in them.
The time for institutions to cancel, and for journals to downsize to just peer review alone and to convert to Gold, with institutions paying the (much lower) author fees out of their cancelation savings, is
after Green OA is at or near 100% (as it already is in some areas of physics and mathematics).
What I think
Tim Gowers and
Jean-Pierre Demailly (and
CERN) should hence be preaching to the world is not "epijournals" but Green OA self-archiving: Mathematicians and physicists (and, before them, computer scientists) did it without mandates, but after 20 years we see that the other disciplines won't do it until their institutions and funders
mandate it.
No-print, no-online, no-subscription, no-author-fee Gold OA journals are not "complements" to subscription journals: they are simply another competing journal.
There does exist a complement to subscription journals today: It is not Arxiv, but Green OA self-archiving by authors, in all disciplines, now at last growing because of OA mandates from their institutions and funders.
When Green OA self-archiving approaches 100% across all disciplines, however, it will indeed become a "competitor," forcing journals to jettison their print and online editions and convert to Gold OA fees to cover their much lower remaining costs" peer review.