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Re: .htaccess a major bottleneck to Semantic Web adoption / Was: Re: RDFa vs RDF/XML and content negotiation

From: Richard Cyganiak <richard@cyganiak.de>
Date: Thu, 25 Jun 2009 23:43:32 +0200
Cc: Danny Ayers <danny.ayers@gmail.com>, bill.roberts@planet.nl, public-lod@w3.org, semantic-web at W3C <semantic-web@w3c.org>
Message-Id: <BE2A8A69-A11D-42F4-AE4F-4C0E18FD4040@cyganiak.de>
To: martin.hepp@ebusiness-unibw.org

On 25 Jun 2009, at 18:44, Martin Hepp (UniBW) wrote:
> As a consequence, we will modify our tool so that it generates  
> "dummy" RDFa code with span/div that *just* represents the meta-data  
> without interfering with the presentation layer.
> That can then be inserted as code snippets via copy-and-paste to any  
> XHTML document.

By "dummy" RDFa markup, do you mean something that is completely  
invisible, so the data wouldn't actually appear on the page, e.g. by  
using style="display:hidden"? That would worry me a bit, because the  
content is invisible without a special RDFa or GoodRelations  
processor, and hence will probably not be kept up-to-date as well as  
information that's plainly visible in a web browser. For evidence,  
have a look at the average SemWeb geek's FOAF profile. Hence, I would  
suggest to keep the information visible. Sorry if I misunderstood and  
that was your intention all along!

Just an idea: How about creating a nicely styled static HTML page that  
sort of looks like an official certificate, with a nice big  
GoodRelations logo etc, and all the data is on the page, annotated  
with RDFa? Might be cleaner than hidden RDFa markup, and a static HTML  
page is hopefully easier to deploy than content-negotiated RDF/XML.

Re .htaccess, you are completely right, it's not an option. For  
average users, the only way they will get content negotiation right is  
if their server (e.g. Virtuoso) or installable web application (e.g.  
Neologism) supports it out of the box.

(On the value of content negotiation in general: I think the key point  
is that any linked data URI intended for re-use, when put into a  
browser by the average person interested in linked data publishing,  
MUST return something human-readable. That's a hard requirement,  
otherwise people will never be confident about what a particular URI  
means and hence they won't re-use. That was the thinking behind the  
Cool URIs note when Leo and I wrote it a few years ago. In the past,  
the only way to get that effect was with content negotiation, so even  
though content negotiation is a pain, it's what we had to do. In the  
present, we have an alternative thanks to RDFa. In the future, maybe  
there'll be a day when the average linked data user will have a  
browser that supports linked data out of the box.)


> Any opinions?
> Best
> Martin
> [1]  http://www.ebusiness-unibw.org/tools/goodrelations-annotator/
> Danny Ayers wrote:
>> Thank you for the excellent questions, Bill.
>> Right now IMHO the best bet is probably just to pick whichever format
>> you are most comfortable with (yup "it depends") and use that as the
>> single source, transforming perhaps with scripts to generate the
>> alternate representations for conneg.
>> As far as I'm aware we don't yet have an easy templating engine for
>> RDFa, so I suspect having that as the source is probably a good  
>> choice
>> for typical Web applications.
>> As mentioned already GRDDL is available for transforming on the fly,
>> though I'm not sure of the level of client engine support at present.
>> Ditto providing a SPARQL endpoint is another way of maximising the
>> surface area of the data.
>> But the key step has clearly been taken, that decision to publish  
>> data
>> directly without needing the human element to interpret it.
>> I claim *win* for the Semantic Web, even if it'll still be a few  
>> years
>> before we see applications exploiting it in a way that provides real
>> benefit for the end user.
>> my 2 cents.
>> Cheers,
>> Danny.
> -- 
> --------------------------------------------------------------
> martin hepp
> e-business & web science research group
> universitaet der bundeswehr muenchen
> e-mail:  mhepp@computer.org
> phone:   +49-(0)89-6004-4217
> fax:     +49-(0)89-6004-4620
> www:     http://www.unibw.de/ebusiness/ (group)
>        http://www.heppnetz.de/ (personal)
> skype:   mfhepp twitter: mfhepp
> Check out the GoodRelations vocabulary for E-Commerce on the Web of  
> Data!
> = 
> = 
> ======================================================================
> Webcast:
> http://www.heppnetz.de/projects/goodrelations/webcast/
> Talk at the Semantic Technology Conference 2009: "Semantic Web-based  
> E-Commerce: The GoodRelations Ontology"
> http://tinyurl.com/semtech-hepp
> Tool for registering your business:
> http://www.ebusiness-unibw.org/tools/goodrelations-annotator/
> Overview article on Semantic Universe:
> http://tinyurl.com/goodrelations-universe
> Project page and resources for developers:
> http://purl.org/goodrelations/
> Tutorial materials:
> Tutorial at ESWC 2009: The Web of Data for E-Commerce in One Day: A  
> Hands-on Introduction to the GoodRelations Ontology, RDFa, and  
> Yahoo! SearchMonkey
> http://www.ebusiness-unibw.org/wiki/GoodRelations_Tutorial_ESWC2009
> <martin_hepp.vcf>
Received on Thursday, 25 June 2009 21:45:16 UTC

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