On Sat, May 21, 2016 at 11:41 AM, Nicolas VIGNERON <vigneron.nicolas@gmail.com> wrote:
BTW, in Rennes, we planned to think on June 18th about importing all the 13 millions books of the BnF catalog into Wikidata (or at least some part of it).

ok, we need to talk before that date :-D
I personally think that it would be much easier to think about "federated" Wikibases, which can communicate with the real Wikidata in a second phase.

We were at least thinking this with the National library of Italy: it would allow them to control their data , but still have the possibility to have all the stuff in Wikidata at the same time.
I personally think that integrations like this have 2 different issues:
* one is technological: you have to map your existing metadata model to another
* the second is social: you are entering a different community, with an existing culture and set of tools, practice.

For example, in WD we have property "title".
Well, when I discussed with librarians in a bibliohackathon in June 2015, we argued a lot if that "title" was the same kind of "title"
that they had in their catalog... Because there are several "titles" in MARC, for example.

Also, the moment that you map an existing catalog in Wikidata, you kind of lose information, and you can't come back.
If you decide, for example, that all the different MARC titles go in property "title" in Wikidata, the moment you import it you don't know which was what, before the importing.

This is one of the reasons Cristian Bacchi designed a MARC-importer that is "lossless", and import MARC in a wikibase-based MARC set of properties...

Aubrey