In message <[email protected]>, Toby Inkster
<[email protected]> writes
If I use the URL of my machine readable data to identity myself (myself
being the subject of discourse) then it immediately creates ambiguities.
What would it mean for the file to have a dc:created property? Would the
value of that property be my date of birth, or would it be the date I
first uploaded my data?
The latter, surely. I thought there were clear conventions for
recording metadata about/within RDF resources.
Say that you adopt the URL <http://tobyinkster.co.uk/me> as the
identifier for the concept of you, and provide an RDF file with that
URL. Any RDF statements within that file with that URL as subject (or
predicate, of course) are about you. The file is simply a container for
these assertions and has no identity as a subject in its own right.
The classic example is that if I use the same URL to represent myself
and my web page, then how can I state that I am the creator of my web
page without also asserting that I'm my own father.
But that's my point: you shouldn't be using the same URL to represent
yourself and your web page! Your web page is a resource, about which
you can make RDF assertions, including (a) that it's a human-readable
version of the RDF associated with <http://tobyinkster.co.uk/me>, and
(b) that the entity represented by <http://tobyinkster.co.uk/me>
authored that page.
The URL of the file and the URL of the subject of discourse must differ
so that we can make unambiguous statements about each, and make
statements about the relationship between the two.
Exactly.
An incredibly easy
way to do this is to just add a fragment to the URL of the subject of
discourse. Examples include:
<http://tobyinkster.co.uk/> represents my web page
<http://tobyinkster.co.uk/#i> represents me
<http://id.loc.gov/authorities/sh85082139> is a web page
<http://id.loc.gov/authorities/sh85082139#concept> is the
abstract concept of Mathematics.
Yes, this also achieves the original goal, but at the expense of
complicating life for Linked Data agents.
The page for Mathematics which you cite doesn't actually have an id
"concept", so strictly speaking the concept URI isn't dereferenceable.
What the agent does get is the complete page as XHTML. It then needs to
parse that page (N.B.), find the alternate representation:
<link rel="alternate" type="application/rdf+xml"
href="/authorities/sh85082139.rdf" />
and go to fetch that RDF resource. This, to my mind, reverses the order
of priority I outlined, privileging the human-readable version of the
subject description over the machine-processible version. It also
assumes that all web page authors will be as punctilious as the Library
of Congress, in producing web pages which are XHTML and which include
"alternate" links to the RDF. So that's raising the bar for authors in
a different way.
Richard
--
Richard Light
