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Re: rdf AND rdf-a?

From: J. Trent Adams <jtrentadams@gmail.com>
Date: Tue, 10 Jun 2008 13:39:44 -0400
Message-Id: <>
To: public-lod@w3.org

Michael -

Adding to what Kingsley said, it's helpful to add RDFa syntax to your 
existing HTML display layer.  While not the panacea, it's a good stepping 
stone for nascent "mesh-up" developers to grok.

For example, if an existing app is already grabbing and parsing the HTML 
(even if you've banned microformats, there're other similar declaration 
inferences), it's a relatively straight forward step to add some RDFa 
handling rules into the mix.  Otherwise, relying entirely on a richer RDF 
representation might require an additional step (which might require a 
longer development cycle).

Assuming it's reasonable to want Yahoo et al. to index your markup, RDFa is 
probably a good thing to do from an SEO perspective anyway.  If you're 
doing that, you've probably settled on the namespaces anyway.  In that 
case, it's also an added benefit to rapid prototypers in your own company 
in addition to the mesh hackers building against the concepts.

 From my experience, whenever data handlers are baked into the display 
layer, I assume there's a measurable probability the HTML jockey's are 
going to muck it up.  A reasonable way around that is through the clever 
use of XSL for the layout handling.  In that case, the output files are 
handled by the core engineers, while the display is prettied up by the 
style crew.  Good separation there.

Thoughts from the edge,

At 09:28 AM 6/10/2008, Kingsley Idehen wrote:

>Michael Smethurst wrote:
>>Morning all
>>The site I'm working on uses microformats fairly heavily. And we've 
>>encountered all the usual problems: accessibility, lack of namespacing / 
>>scope etc. Anyway for accessibility reasons we've just updated our 
>>standards to prohibit the use of the microformat abbreviation design 
>>pattern (so most interesting microformats). This may change when we do a 
>>little more testing but there's no date for that so it's looking like 
>>microformats are bye-bye
>>Pretty soon (honest) we'll be putting RDF views of the data live
>>So my questions are:
>>- if we have full RDF, should we also be using rdf-a?
>>- if so what would be the benefits (yahoo search stuff?)?
>>- and what would be the costs (ham-fisted html hackers wrecking the 
>>templates springs to mind ;) )?
>>any pointers much appreciated
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>The main benefit of RDFa is that you broaden the scope of User Agent''s 
>capable of discovering and generating RDF.  This is why I've suggested the 
>following approaches to exposing Linked Data (at least one of the 4):
>1 <link rel="alternate" .../> (you can do many things with the LINK tag's 
>rel attribute which is commonly used for auto-discovery of content anyhow)
>2.  Content Negotiation
>3.  GRDDL
>4.  RDFa
>We just want to provide as many options as possible to the user agents 
>seeking the raw data behind or associated with a given Web Page.
>I would also encourage those developing user agents to include the options 
>above into their RDF discovery process. On our part, our user agents (RDF 
>Browsers, Sponger, and SPARQL processor) apply all 4 of the methods above, 
>but we start off with Content Negotiation first, and then work our way 
>down. Of course we also need to get our Browsers to remember options 2-3 
>where appropriate since they are themselves Web pages that may be consumed 
>by other user agents that may only support 1 of the options :-)
>Kingsley Idehen       Weblog: http://www.openlinksw.com/blog/~kidehen
>President & CEO OpenLink Software     Web: http://www.openlinksw.com

J. Trent Adams

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Received on Tuesday, 10 June 2008 20:02:02 UTC

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