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

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Mon, 29 Jun 2009 08:03:10 -0400
Message-ID: <4A48AD7E.3080605@openlinksw.com>
CC: public-lod@w3.org, semantic-web at W3C <semantic-web@w3c.org>
Martin Hepp (UniBW) wrote:
> Hi Tom:
>
> >Amen. Thank you for writing this. I completely agree. RDFa has some
> >great use cases but (like any technology) has its limitations. Let's
> >not oversell it.
> We seem to agree on the observation, but not on the conclusion. What I 
> want and suggest is using RDFa also for exchanging a bit more complex 
> RDF models / data by simply using a lot of div / span or whatever 
> elements that represent the RDF part in the SAME document BUT NOT too 
> closely linked with the presentation level.
>
> <body>
> <h1>This is the car I want to sell</h1>
> Actually, a pretty cool car, for only $1.000. Offer valid through July 
> 31, 2009
>
> <span>
> ... my whole RDF in RDFa
>  </span>
> <body>
>
> The advantage of that would be that
>
> - you just have to maintain ONE file,
> - data and metadata are close by, so the likelihood of being up to 
> date increases, and
> - at the same time, the code does not get too messy.
> - Also - no problems setting up the server (*).
> - Easy to create on-line tools that generate RDFa snippets for simple 
> pasting.
> - Yahoo and Google will most likely honor RDFa meta-data only.
>
> Also note that often the literal values will be in content attributes 
> anyway, because the string for the presentation is not suitable as 
> meta-data content anyway (e.g.  dates, country codes,...)
>
> I think the approach sketched above would be a cheap and useful way of 
> publishing RDF meta-data. It could work with CMS / blogging software 
> etc.  Imaging if we were able to allow eBay sellers to put 
> GoodRelations meta-data directly into the open XHTML part of their 
> product description.
>
> The main problem with my proposal is that there is the risk that 
> Google considers this "cloaking" and may remove respective resources 
> from their index (Mark raised that issue). If that risk was confirmed, 
> we would really have a problem. Imagine me selling Semantic Web markup 
> as a step beyond SEO ... and the first consequence of following my 
> advice is being removed from the Google index.
>
> A second problem is that if the document contains nodes that have no 
> counterpart on the presentation level (e.g. intermediate nodes for 
> holding n-ary relations), then they will also not be dereferencable. 
> The same holds for URIs or  nodes that are outside the scope of the 
> actual RDFa / XHTML document - I see no simple way of serving neither 
> XHTML nor RDF content for those.
Martin,

If Google doesn't see invisible DIVs as cloaking, the issue vaporizes.

Also, if people take the SEO + SDQ (Linked Data Expressed in RDFa) 
approach they will at least remain in the Google index via usual SEO 
oriented keyword gimmickry, albeit generally suboptimal.

If we make a recipe doc showcasing these issues, we will more than 
likely get Google to recalibrate back to the Web; especially if we can 
demonstrate that other search engine players --that have support RDFa -- 
not being afflicted with the same cloaking myopia.

Kingsley
>
> Best
>
> Martin
>
>
>
> Tom Heath wrote:
>> Martin,
>>
>> 2009/6/27 Martin Hepp (UniBW) <martin.hepp@ebusiness-unibw.org>:
>>   
>>> So if this "hidden div / span" approach is not feasible, we got a problem.
>>>
>>> The reason is that, as beautiful the idea is of using RDFa to make a) the
>>> human-readable presentation and b) the machine-readable meta-data link to
>>> the same literals, the problematic is it in reality once the structure of a)
>>> and b) are very different.
>>>
>>> For very simple property-value pairs, embedding RDFa markup is no problem.
>>> But if you have a bit more complexity at the conceptual level and in
>>> particular if there are significant differences to the structure of the
>>> presentation (e.g. in terms of granularity, ordering of elements, etc.), it
>>> gets very, very messy and hard to maintain.
>>>     
>>
>> Amen. Thank you for writing this. I completely agree. RDFa has some
>> great use cases but (like any technology) has its limitations. Let's
>> not oversell it.
>>
>> Tom.
>>
>>   
>
> -- 
> --------------------------------------------------------------
> 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
>
>
>
>   


-- 


Regards,

Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Monday, 29 June 2009 12:03:49 UTC

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