What is RDFa? – Mark Birbeck
I was re-viewing Birbeck’s Google TechTalk on RDFa, and really liked his brief explanation about what RDFa actually is. So thought I’d quote Birbeck from his talk:
I’m using RDFa as a bit of a shorthand, because I’m saying really “embedded metadata”. I’m saying any way of actually putting information into the HTML page, rather than the traditional semantic web approach of having a “separate channel”. By separate channel, I’m saying you might have had an RDF-XML document, or even an RSS feed you could regard as a kind of semantic channel of information. But a channel of information that’s kind of distinct from the web page.
Whereas what we’ve done with RDFa, and what the people behind Microformats were doing, basically the same goal, was actually make the HTML page the carrier of the metadata. And some times it’s carrying metadata about other things, and sometimes it’s carrying metadata about itself. So really, when I say RDFa (throughout this talk) I’m generally meaning those kind of solutions that allow you to embed metadata.
The reason I’m favoring RDFa is because it’s very specific goal was to align itself with RDF, so it’s actually much more precise than Microformats, but the idea is the same that you embed information [in the HTML page].
So that’s the purpose of RDFa according to Birbeck. As far as what RDFA actually is:
As for what it is, it’s a W3C standard now. It’s something we’ve been working on for four or so years – which I guess is quick for the W3C, we’ve been working on it for quite a long time, and it recently became a standard.
And it’s very much about defining the syntax of how you embed information. It’s not really about saying what the vocabularies should be. Whereas Microformats is very much more about the vocabularies.
And a good example of the flexibility of what that brings is when Google did its Rich Snippets, it just came out with its own vocabulary. It got a lot of stick for it from the Semantic Web community, or some there. But the point is that you were able to just come out with your own vocabulary, because RDFa is about the syntax and the structure, rather than the actual terms.
So it’s very much in the spirit of the Web in the sense that it allows people to define their own vocabularies or reuse existing vocabularies, and put them into their documents however they see fit.
So RDFa is a standard, and its goal is embedding metadata in pages.
That’s a very nice exaplanation I must say. Please view the entirety of Birbeck’s talk for deeper insight into the mechanics of RDFa.