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Re: RDF in 500 words

• To: Dave Winer <dave@u...>
• Subject: Re: RDF in 500 words
• From: Paul Prescod <paul@p...>
• Date: Sun, 17 Nov 2002 15:37:49 -0800
• Cc: Danny Ayers <danny666@v...>, Xml-Dev <xml-dev@l...>
• In-reply-to: <EBEPLGMHCDOJJJPCFHEFAELLIHAA.danny666@v...>
• References: <EBEPLGMHCDOJJJPCFHEFAELLIHAA.danny666@v...> <071601c28d9c$72f48fc0$33a1dc40@murphy>
• User-agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en-US; rv:1.2b) Gecko/20021016

Why would you take a jab at someone's attempt to explain a technology in 
easy to understand terms?

Dave Winer wrote:

> Danny here's some free advice.
>
> Go build some apps that kick butt.
>
> And forget about debates.
>
> They don't matter.
>
> That's less than 500 words.
>
> I bet it's less than 100.
>
> Have a nice day.
>
> Dave
>
>
> ----- Original Message -----
> From: "Danny Ayers"
> To: "Xml-Dev"
> Sent: Saturday, November 16, 2002 9:51 AM
> Subject:  RDF in 500 words
>
>
>
> >There are 6 key documents in the RDF suite, and just the Primer [1] now
>
> runs
>
> >to 89 pages of A4. To counter allegations that RDF is altogether too
> >heavy/complicated/difficult/wordy, I thought I try Andrew's 500 word
> >challenge on it.
> >
> >
> >--------------------------------
> >In RDF, a resource is something that can be identified on the web, and a
> >description is something said about a resource.
> >
> >Resources have a universal identifier, their URI, which in the case 
> of web
> >pages will be the same as their address (URL). Pretty much anything else
> >(people, places, concepts) can be identified in this way by assigning
>
> URIs.
>
> >Descriptions are made in RDF using statements. A statement has three
>
> parts:
>
> >the thing being described, the characteristic of interest and the 
> value of
> >that characteristic. For example, the thing being described might be a
>
> book,
>
> >say "A Christmas Carol"  the characteristic of interest  (property) the
> >author, and the value would be the name of the author, "Charles Dickens".
>
> In
>
> >RDF jargon these three parts are the subject, predicate and object, and
> >together they form a triple. The subject is a resource, the predicate 
> is a
> >special kind of resource and the object can either be another resource or
> >literal text.
> >
> >As a resources, the predicates are also unambiguously identified using
>
> URIs,
>
> >but the same predicate can be reused - when we ask who the author of a
>
> book
>
> >is, we are asking the same question whichever book we are talking 
> about or
> >whoever happens to be the author. If we want to say more about a
>
> particular
>
> >book, we can use its identifier in another statement with a different
> >predicate (property) and object (value). The basic nature of 
> resources and
> >predicates are defined with the help of a small set of terms in the RDF
> >specifications. This set of terms allows us to give more information in
>
> our
>
> >descriptions, so we could define a classification 'paperback' and say 
> that
> >this is a kind of book. The class 'book' would in turn be described as a
> >kind of resource.
> >
> >In this example we have identified the author by the text of their name,
>
> but
>
> >usually it is more useful to use a URI as that will be unambiguous, and
> >allow us to say things about the author as well.  So we could have 
> another
> >statement that says that this author's favourite colour is blue. Our
> >knowledge can be expressed as these two statements, but as the author 
> is a
> >common feature in this we can visualise the knowledge as the three
>
> resources
>
> >linked by the connection from the book to the author and from the author
>
> to
>
> >the colour blue. This structure is an example of an RDF graph. There may
>
> be
>
> >other resources that we can link in as well, like books by the same 
> author
> >or the book's publisher.
> >
> >It  isn't entirely always necessary or even possible to identify
>
> resources.
>
> >Let's say we have identified the book and the colour blue. We can still
>
> make
>
> >two statements,   "A Christmas Carol" was written by X,  and the X's
> >favourite colour is blue. This can still be visualised as a graph with
>
> three
>
> >items and two connections, and in the jargon X is known as a blank node.
> >
> >seeAlso: http://w3.org/RDF
> >-----------------------------------
> >
> >Cheers,
> >Danny.
> >
> >[1] http://www.w3.org/TR/2002/WD-rdf-primer-20021111/
> >
> >-----------
> >Danny Ayers
> >
> >Semantic Web Log :
> >http://www.citnames.com/blog
> >
> >
> >
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• References:
  • RDF in 500 words
    • From: "Danny Ayers" <danny666@v...>
  • Re: RDF in 500 words
    • From: "Dave Winer" <dave@u...>

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