If you’re very observant, or if you just spend a lot of time poking at Google or Bing, over the last year or so perhaps you’ve noticed that the search engines are returning results that are a lot more informative than they used to be. “Old” style search are familiar and straightforward; they’ve got a page title, a URL and some text (usually from the content).
The type of search results that are becoming increasingly more common use what are called “rich snippets” of information. A rich snippet drops a lot more data right onto the search page; in addition to the standard information, it can include review ratings, breadcrumb navigation and a number of other details. In the example of rich snippet results shown below, you can find important information from the recipes like cooking time and calories in the results output.
On the same search results page, you’ll generally find a mix of old-style results and rich-snippet results. What’s the difference between the web pages that return the different types of results? It’s not some secret search engine conspiracy. Rather, the difference is caused by some of the markup language included in the code that generates each page.
Pages that return rich-snippet results in search make use of special extensions to the HTML5 language that allow structured data markup. Structured data markup is a fancy term for a relatively simple coding vocabulary that directly addresses search engines (and other types of machine intelligence) to help them “understand” a web page’s content. As with nearly everything else in the technology world, there are competing standards for structured data markup. Working groups for the W3C, the organization responsible for managing HTML standards, have established both RDFa (Resource Description Framework in Attributes) and Microdata vocabularies to provide structured data markup.
Major search engines began working to support structured data markup when the HTML5 standard was first published. It’s only been in the last year or so that enhanced rich-snippet results have started to show up frequently in search results. You’ll find the proportion of rich search results varies according to the subject you’re searching becuase right now the search engines support some data types better than others.
The “recipe” schema, for example, was one of the first supported data types — which is why a “peanut butter and bacon” recipe search will turn up a lot of rich search results. If you’re moderately alert, you’ll notice that Google even has a specialized recipe search. The “author” schema, on the other hand, is still a work-in-progress for the search engines because of the schema’s spam potential; thus our search for the brilliant Dr. Feynman returns a greater proportion of standard search results.