Hi Gregor,
thanks for your great comments! I am trying to answer them here.
2012/7/5 Gregor Hagedorn g.m.hagedorn@gmail.com:
On https://meta.wikimedia.org/wiki/Wikidata/Notes/URI_scheme#Proposal_for_Wikid... I am missing the arguments why Wikidata needs the multitude of URI forms. The list needs commenting and arguments why
"URIs should be canonical within Wikimedia projects"
is given up.
It is not. There is a canonical form. This does not mean it is the only one, but every other form can be canonicalized into the canonical one, and tools should work with that. (This is the same meaning as with titles in Wikipedia: whereas both https://en.wikipedia.org/wiki/Obama and https://en.wikipedia.org/wiki/Barack_Obama are URLs for the article on Barack Obama, only the latter one is canonical -- the first one is just a convenience URL).
(Of lesser importance, I wonder why the internal opaque ID has to be prefixed by a letter (Q) - why not a simple number?)
Originally this comes from a limitation in XML: the local part of a QName must not start with a number, so we prefixed it with a letter. As most export formats should also work in XML, we took that as an important enough restriction to make it move into our Identifiers. Furthermore, using a letter like Q which is rather seldom otherwise increases the likelihood of a Wikidata ID being recognized with little context (i.e. in a text, Q7237 will be in the end more readily recognized as a Wikidata ID than 7237 alone).
At them moment I believe a choice should be made between: http://%7Bsite%7D.wikidata.org/wiki/%7Btitle%7D and http://wikidata.org/title/%7Bsite%7D:%7Btitle%7D but perhaps the argument why both are needed could be added.
This is for merely technical reasons. Both URLs are convenience URLs anyway. The canonical one is the one with the ID.
On the issue of interlanguage/interwiki linking, I believe the semantics should not be opposite in Wikidata and Wikipedias, see my comment https://meta.wikimedia.org/wiki/Talk:Wikidata/Notes/Wiki_links
Added comment there. In short, the current proposal is actually more consistent over all the Wikimedia-projects, which means it is inconsistent how it is handled "internally" within the Wikipedia-projects. This means that the current suggestion is more or less what the software already does, and does not require much additional implementation.
Gregor
Cheers, Denny