As I understand this module cooperates with core rdf module.

Nevertheless Google says that they prefer microdata.

http://www.google.com/support/webmasters/bin/answer.py?answer=1211158
Why microdata? Why not RDFa or microformats?
Historically, we’ve supported three different standards for structured data markup: microdata, microformats, and RDFa. Instead of having webmasters decide between competing formats, we’ve decided to focus on just one format for schema.org. In addition, a single format will improve consistency across search engines relying on the data. There are arguments to be made for preferring any of the existing standards, but we’ve found that microdata strikes a balance between the extensibility of RDFa and the simplicity of microformats, so this is the format that we’ve gone with.

So, what about doing it with microdata?

Comments

scor’s picture

scor commented

several reasons. when they evaluated the syntaxes, they looked at RDFa 1.0 which didn't look as simple as microdata or the newer RDFa 1.1. RDFa 1.1 addresses a lot of the usability issues which were raised / learnt from the microdata community. RDFa 1.1 Lite was presented at the recent schema.org workshop where the schema.org sponsors were present, and there was a consensus to support multiple formats. The RDFa integration in Drupal has been in the works for 2+ years and since Drupal 7 ships with the RDFa syntax in core, why not using it? microdata also presents some challenges: it is "picky" wrt to the placement of the attributes, while RDFa allows more flexibility (check Lin's blog for more details on the differences and challenges). RDFa and microdata are very similar at a high level (structured data via adding attributes in HTML, attribute-value pairs grouped into types). Google hasn't said they will penalize those who don't use microdata.

dropbydrop’s picture

dropbydrop commented

Thanks Stephane for your great answer. I really understood a lot.

Till now my experiments with rdfa + schema.org markup did not produce any snippet at google rich snippet tool, so I was wondering if they insist on using microdata for schema.org.

If it works for you and other maybe I have to recheck the syntax.

scor’s picture

scor commented
Status: Active » Closed (won't fix)

please create an issue specifically about what you were trying so we can debug (include the steps you took to set it up). Were you trying other types other than the ones known to work (person, event, recipe)?