Semantic Web Markup for Blogs ?!?

May 1st, 2007

I read The Definitive Guide to Semantic Web Markup for Blogs expecting it to be about how to make effective use of RDF in blogs to add explicit semantic information. I was suprised to find it offered some pragmatic advice about how to use the most basic of HTML tags (e.g., TITLE and H1, H2, H3, ..) so as not to confuse search engines.

Unbelievably, nearly every WordPress, MovableType, or TypePad theme that I’ve come across in the past year fails a simple test for truly semantic (and Google-recommended) XHTML markup. … Your goal is to describe each page to the search engines through the use of hierarchical XHTML tags (

While the post contains lots of useful advice, it’s clearly not about big-S-big-W Semantic Web or even (IMHO) lowercase semantic web. If anything, its about another SW — SEO Web.

There are several plugins for WordPress and other blog frameworks that add RDF data to your blog, such as SIOC Exporter for WordPress as well has various plugins to add SKOS and FOAF data. Many people add additional RDF information in their RSS 1.0 feeds. Blogs make heavy use of folksonomies through their tagging and category systems and some have information embedded in microformats and RDFa. Finally, a number of blogs, e.g., FieldMarking, are experimenting with the notion of “data blogging” — using a blog as a medium to publish a stream of data.

If we generalize a bit to other forms of social media, like Wikis or Flickr, there’s even more going on that clearly falls in the upper or lower case views of the semantic web — Semantic MediaWiki and machine tags spring to mind.