Read the article.

Search New Central has now published an interview with Jay Myers, Lead Development Engineer for Best Buy, on the whys and wherefores of implementing RDFa on their site.

“We really didn’t go into it with any expectations. We just wanted to see if it was something we might want to do. That’s why we were caught by surprise by the results… we weren’t really expecting any.”

“Within just a couple of months, we began to see an increase in our organic search results. Before long, it had increased by 30% over historical rates. We also saw an increase in our click-through rate.”

“I found that RDFa was a much more stable concept – based on the use of long established vocabularies (also known as ontologies) that have existed for years.”

The interview

If Massachusetts pursues enriching our content, RDFa seems a more likely candidate. We prefer to adopt things that have been created and promulgated by standards bodies: they are more stable, the deliberative process surfaces and resolves problems beforehand, and are the only reliable basis for interoperability.

The solutions described in the following apply to deployment scenarios in which the RDF data and the HTML data is served separately, such as a standalone RDF/XML document along with an HTML document. The metadata can also be embedded in HTML, using technologies such as RDFa [...], microformats and other documents to which the GRDDL [...] mechanisms can be applied. In those cases the RDF data is extracted from the returned HTML document.

What is your opinion? Do you have practical experiences — that is: no toy setup — in designing URIs in an XHTML+RDFa environment?

… pretending to be constructive, and in order to make things less biased, I embedded a dynamic page item that allows you to create your own, tailored comparison.

Check out Benjamin Nowack’s careful comparison of RDFa to other metadata embedding techniques. The one downside he points out: RDFa does not currently validate in XHTML 1.0. That’s true, but we had no other choice to achieve the features we need:

• independence: you pick your vocabulary of metadata terms
• modularity: you can reuse other vocabularies
• evolvability: you can change the meaning of your vocabulary over time (yeah, RDF!)
• DRY: don’t repeat yourself, if you render the data in HTML, why repeat it in the structured form?
• in-context: the metadata is right next to the data it describes, and if you copy and paste the HTML, you get the metadata along with it.

But fear not: RDFa does not break anything in today’s browsers. Not even in XHTML strict rendering mode. That’s a big deal, and it means that our upcoming effort to standardize RDFa for XHTML1 is going to be fairly straight-forward.

One significant advantage of RDFa: you can express metadata about other documents (embedded images) and about fragments of the document (a blockquote). And another significant advantage: you can aggregate content from multiple sources, and the metadata schemas will not conflict, thanks to XML namespaces.

Meanwhile, Evan Prodromou compares RDFa to Microformats. He seems worried that the disagreements will be problematic. We don’t think so. Microformats are useful for expressing a few, common, well-defined vocabularies. RDFa is useful for letting publishers mix and match any vocabularies they choose. Both are useful.

And since RDFa is more generic than Microformats, we have a proposal for transforming Microformats to RDFa. We’re still debating this, but it’s very promising. In fact, our calendar bookmarklet uses this technique to read both iCal RDFa, and the hCal microformat.