Many siteowners and developers are unsure that rich snippets, in any form, offer sufficient ROI to make the effort worthwhile. Having to choose between RDFa and microformats as a medium just further complicates the decision.

Is it worthwhile to recode my site?

Let’s take a look first at the ROI question.

• Either gives you the ability to make more information available to the search engines, in a format that is more easily understood, semantically. That’s a major plus, from a relevancy standpoint;

• Either can be included in the SERPs, in the form of rich snippets, providing more information to entice the user to visit your site.

Both obviously can result in better SERPs ranking, higher CTR and more targeted visitors. To me, that translates into more conversions. So what was that question about ROI again?

Which one is better?

Now here, it gets a little stickier. Personal preferences, comfort level with coding, confidence in Google and W3C… they all can come into play. My personal preference is RDFa, partly because I think it is more versatile and partly because I think W3C, as the backer of the RDFa model, has approached the question with less self-interest. But that’s just me. I also think that RDFa will ultimately become the preferred medium, and I hate to have to do things twice.

Microformats

Essentially, microformats are simply a set of attribute tags… actually called entities, derived from HTML, to classify certain types of data. These hTags can describe a person, business, event, product or review, for instance. Each entity has properties, as well, such as name, address, email, company name, job title.

Here's an example of a short HTML block showing sample basic contact information for some random idiot:

 <div>
 <img  src="/www.example.com/Doc_Sheldon.jpg" />
 <strong>Doc  Sheldon</strong>
 Writer  at Search News Central
 200  Any St
 Anytown,  ZZ 12345
 </div>

Here is the same HTML marked up with the hCard (Person) microformat.

 
 <div  class="vcard">
 <img  class="photo" src="/www.example.com/Doc_Sheldon.jpg"  />
 <strong  class="fn">Doc Sheldon</strong>
 <span  class="title">Writer</span> at <span  class="org">Search News Central</span>
 <span  class="adr">
 <span  class="street-address">200 Any St</span>
 <span  class="locality">Anytown</span>, <span  class="region">ZZ</span>
 <span  class="postal-code">12345</span>
 </span>
 </div> 

You’ve probably heard that Google not long ago adopted the GoodRelations ontology for microformats. GoodRelations is a language developed by Martin Hepp, specifically for RDFa. By adopting it, Google has essentially accepted that language as being compatible with their version of microformats. (You can take a closer look at Martin’s schema on his GoodRelations Language Reference page.)

Therein is the key, I think… their version. While Google is certainly dominant in the search engine field, they’re NOT the only search engine. To offer such a means of assisting the trend toward a Semantic Web would be noble, were no such other offering on the table. But the W3C has already endorsed RDFa. That makes Google’s refusal to accept RDFa suspect, in my mind.

While microformats can be integrated well with HTML and CSS, I believe their lack of scalability make them impractical in the long run. At present, however, microformats will validate with HTML4 and XHTML 1.0, whereas RDFa validation with HTML4 is still under development. That is not to say that RDFa won’t work with HTML4, only that it won’t validate.

RDFa

RDFa uses some simple XHTML attributes to categorize data, to an extent not available with microformats. RDF triples convey much more information, in a format that is readily interpreted by search engines. This categorization is becoming increasingly helpful – even necessary – as the web becomes more semantic in nature.

An example, taken from W3.org’s website:

In her blog's footer, Alice declares her content to be freely reusable, as long as she receives due credit when her articles are cited. The XHTML includes a link to a Creative Commons license:

 
 All content on  this site is licensed under
 <a  href="http://creativecommons.org/licenses/by/3.0/">
 a Creative  Commons License
 </a>.

However, using RDFa, a minor modification removes any uncertainty as to the meaning of that link:

 
 All content on  this site is licensed under
 <a rel="license" href="http://creativecommons.org/licenses/by/3.0/">
 a Creative  Commons License
 </a>.

Now, the browsers can clearly understand that this link specifies the license of Alice’s blog.

Similarly, the blog post’s title and author can be clearly called out for the browser. In simple HTML, it would appear like this:

 
 <div>
 <h2>The  trouble with Bob</h2>
 <h3>Alice</h3>
 ...
 </div>

Whereas in RDFa, it would be:

 
 <div xmlns:dc="http://purl.org/dc/elements/1.1/">
 <h2 property="dc:title">The  trouble with Bob</h2>
 <h3 property="dc:creator">Alice</h3>
 ...
 </div>

Obviously, the user would see both identically, but the search engine will now recognize that “The trouble with Bob” is the post’s title, and that Alice is the author. Any semantic ambiguity that existed before has now been removed. For more on this concept and others, I highly recommend that you read the W3 RDFa Primer

Note: The terms used in RDFa markup are those specified in Dublin Core, which has been adopted by W3C as the recommended ontology for RDFa.

Summary

So which is better? It depends upon what you’re looking for. As I said earlier, I feel RDFa is the more appropriate choice. Yes, the coding modifications are slightly more intricate, but not much.

And it has the benefit of being more explicit, offering more versatility and I believe, greater longevity. Above all, it accomplishes far more, toward achieving semantic search capability.

To defer the task of learning RDFa and opt instead for the somewhat quicker microformats integration is certainly an option. But if you do so, it’s possible that you’ll find yourself doing it all over again later, to incorporate RDFa into your site’s design. My recommendation would be to either implement RDFa technology now, or make it a key part of your next redesign. Wouldn’t you rather lead your competition, than follow them?

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