- From: Kingsley Idehen <kidehen@openlinksw.com>
- Date: Mon, 29 Jun 2009 08:03:10 -0400
- 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 12:03:50 UTC