W3C home > Mailing lists > Public > public-lod@w3.org > March 2010

DC-HTML as a linked data format

From: Paul Houle <ontology2@gmail.com>
Date: Mon, 8 Mar 2010 12:49:56 -0500
Message-ID: <3e12f6f41003080949r601cfd8ei801c76e0363456b7@mail.gmail.com>
To: Linked Data community <public-lod@w3.org>
     Hello,  I was talking to Kingsley the other day about lightweight
mechanisms for adding linked data to existing HTML pages.  I started adding
some geotags and some statements from the Dublin Core vocabulary,  using the
DC-HTML format:

http://dublincore.org/documents/dc-html/

 I was pretty impressed with the ease of adding simple statements,  as seen
in a page for a topic:

http://ny-pictures.com/nyc/photo/topic/3461/Empire_State_Building

or in a page for an individual photograph

http://ny-pictures.com/nyc/photo/picture/29218/empire_seen_top_rockefeller_smoggy

     I see that DC-HTML has some serious drawbacks (you can only make
statements about the page that you're on) but it seems much more practical
than RDFa on today's web.  RDFa is certainly more capable,  but I've got a
number of issues with it:  most seriously,  I don't want to commit to XHTML
output,  because it's technically difficult to built web systems that always
output valid XHTML.  (I suppose I could generate everything from the XML
DOM,  but then I can't ever hire a web designer to make my templates;  for
that matter,  just changing something on one of the pages could go from
being a 5 minute job to a 5 hour job for a programmer.  ASP.NET offers a
pretty good answer to this problem,  but it comes with a lot of baggage that
I'd rather avoid.)  XHTML has rendering issues on today's web browsers,  and
also,  I'm pretty concerned about interoperability:  because the RDFa spec
offers web developers so many choices,  I think they'll often make the wrong
ones.

    Here are some questions I'd like to see answered.

(i) Are there useful online validators for DC-HTML and RDFa?  [Validation
can mean different things:  on one hand,  there's "view the triples asserted
here" but I'd also like some help knowing that I'm using standard (or "well
known") predicates and that I'm formatting my data correctly.  (For
instance,  is my XSD#Date formatted the right way,  are my geo coordinates
correctly formatted,  etc.)
(ii) What's the 'standards' basis for DC-HTML?  Pretty clearly it's
reccomended by the DCMI,  but because it's about asserting RDF triples,  I
could see it coming under the scope of the W3C.
(ii) What are the practical statuses of DC-HTML and RDFa support in the
"wild"?
Received on Monday, 8 March 2010 17:50:28 UTC

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