Re: public-swd-wg@w3.org

Thanks a lot Ed. I have updated the FAQ with your suggestions.

Ivan

Ed Summers wrote:
> On behalf of the Semantic Web Deployment Working Group I reviewed the
> semweb-faq [1] in light of SKOS. I have a few suggestions which I've
> included below with a bit of commentary. Please feel free to use
> whatever is useful in these suggestions.
> 
> I also crafted a short answer to a question "What is SKOS?"--which was
> largely pulled from a recent writeup of SKOS & RDFa by Alistair Miles
> [2]. Alistair has given his approval for the text to be used if you
> think it would be helpful to directly address SKOS in the faq.
> 
> Thanks for asking for our input on this very useful document!
> 
> //Ed
> 
> -----
> 
> ... Must I use ontologies for Semantic Web Applications?
> 
> "These different technologies differ in expressiveness but also in
> complexity: applications have a choice (RDF Schemas represent the
> simplest ontology level, OWL Full being the most complex one, SKOS
> when less rigorous terminologies, glossaries, are to be used, etc).
> They also have a choice of not to use any of those; the usage of
> ontologies is not a requirement for Semantic Web applications."
> 
> I think it's important to encourage people to reuse ontologies before
> creating their own, and SKOS is a good example of a re-usable
> ontology. So here is some slightly modified language.
> 
> These technologies differ in expressiveness but also in complexity.
> Applications have a choice along a range from RDF Schema for
> representing the simplest ontology level, to OWL Full for maximum
> expressiveness. In addition semantic web users are encouraged to
> leverage existing ontologies where possible: e.g. SKOS for
> representing basic structures like thesauri, taxonomies or other
> controlled  vocabularies. Good places to look for existing ontologies
> are detailed elsewhere in this FAQ [3].
> 
> -----
> 
> ... tagging, folksonomies
> 
> "While tagging is easy and somewhat useful, it destroys a lot of the
> semantics of the data. In the Semantic Web, instead of tagging data
> items with strings, they can be related to other resources which can
> be uniquely identified, like ones representing people and places. The
> relationships are very specific, like who took the photograph, who is
> in the photograph, where the photograph was taken."
> 
> It seems to me that the semantic web community is beginning to see
> that folksonomy and tagging may have a role to play in the semantic
> web. For examples of this see flickrwrapper at dbpedia [4] and
> Alistair Mile's latest thinking on SKOS [2]. I think it would serve the
> semantic web effort well by encouraging this collaboration rather than
> dismantling it. So here's a rephrasing of the above:
> 
> While tagging is easy and somewhat useful, it often destroys a lot of
> the semantics of the data. A folksonomy tag is typically 2/3 of a RDF
> triple. The subject is known: e.g. the URL for the flickr image being
> tagged, or the URL being bookmarked in delicious. The object is known:
> e.g. http://flickr.com/photos/tags/cats or
> http://del.icio.us/tag/cats. But the predicate to connect them is
> often missing. Machine-tags [5] lend themselves to RDF more since they
> better capture the relationship between the subject and the object.
> Folksonomy providers are encouraged to capture or infer the semantics
> around their tags and to leverage semantic web technologies such as
> RDF and SKOS to publish machine readable versions of their concept
> schemes.
> 
> -----
> 
> ... What is SKOS?
> 
> The Simple Knowledge Organization System (SKOS) is an ontology for expressing
> the basic structure and content of concept schemes such as thesauri,
> classification schemes, subject heading lists, taxonomies, glossaries,
> folksonomies, other types of controlled vocabularies. It provides a standard,
> low-cost way of migrating existing concept schemes to the Semantic Web,
> so that they can be used as-is for the development of lightweight Semantic Web
> applications. SKOS is increasingly seen as a bridging technology, providing
> the missing link between the rigorous logical formalism of ontology languages
> such as OWL and the chaotic, informal and weakly-structured world of social
> approaches to information management, as exemplified by social tagging
> applications.
> 
> [1] http://www.w3.org/2001/sw/SW-FAQ
> [2] http://isegserv.itd.rl.ac.uk/blogs/alistair/archives/84
> [3] http://www.w3.org/2001/sw/SW-FAQ#findont
> [4] http://www4.wiwiss.fu-berlin.de/flickrwrappr/
> [5] http://www.flickr.com/groups/api/discuss/72157594497877875/
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
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