On May 18, 2009, at 14:45, Dan Brickley wrote:
On 18/5/09 10:34, Henri Sivonen wrote:
It seems to me that the positions that RDF applications should
"Follow
Their Nose" and that link rot is not dangerous (to RDF) are
contradictory positions.
That's a strong claim. There is certainly a balance to be found
between taking advantage of de-referencable URIs and relying on
their de-referencability. De-referencing is a privilege not a right,
after all.
If there's value in apps dereferencing namespace URIs, those URIs
going undereferencable leads to loss of value. Hence, link rot would
cause loss of value i.e. be 'dangerous' by breaking something.
If I lost control of xmlns.com tommorrow, and it became un-rescuably
owned by offshore spam-virus-malware pirates, that doesn't change
history. For nine years, the FOAF documentation has lived there, and
we can use URIs to ask other services about what they saw during
that period: http://web.archive.org/web/*/http://xmlns.com/foaf/0.1/
Do any RDF consumer apps that dereference namespace URIs actually fall
back on web.archive.org?
If I'm a FOAF author, what recourse do I have if URI dereferencing-
based functionality breaks in some apps due to xmlns.com going
unavailable when other apps have hard-coded xmlns.com URIs so if I
simply changed my predicates I'd break existing apps? At least authors
who rely on Y!/AOL/Google serving JS libraries can start using a copy
of any JS library on another CDN without changing how the script runs.
Since there is useful information to know about FOAF properties and
terms from its schema and human-oriented docs, it would be a shame
if people ignored that. Since domain names can be lost, it would
also be a shame if directly de-referencing URIs to the schema was
the only way people could find that info. Fortunately, neither is
the case.
I wasn't talking about people but about apps dereferencing NS URIs to
enable their functionality.
That link rot hasn't been a practical problem to the Semantic Web
community suggests that applications don't really Follow Their Nose
in
practice. Can anyone point me to a deployed end user application that
uses RDF internally and Follows Its Nose?
The search site, sindice.com does this:
Thanks.
Whether you consider sindice.com end-user facing or not, I don't know.
I wouldn't characterize it as an end-user app. It exposes terms like
"RDF" and "triples" and shows qnames to the user.
--
Henri Sivonen
hsivo...@iki.fi
http://hsivonen.iki.fi/
