Search engines are interested in getting structured data from websites for better user experience in searching. Google uses them for rich snippets in the search results, to show things like ratings and author pictures.
There are three different ways to markup structured data.
Microformats let you markup data with pre-existing attributes. Both Microdata and RDFa are more flexible, as they let you use prebuilt schemas or create your own
Which should you use? Glenn uses microformats most of the time as they’re simpler, but they only cover some things. Microdata can be used to describe more unusual objects.
Glenn talked through how to mark-up a Yorkshire pudding recipe using microformats:
- You can have a property inside another, such as yield inside the summary.
- You can have marked up data within paragraphs of freeform text.
- Some properties have parent-child structure. For example, ‘ingredient’ has the child properties ‘amount’ and ‘name’.
- Properties can take data that aren’t text, eg has to be an image
- Some data are more complex. For example there are many ways to write same date, so you have to use a specific data structure that says what the text means, eg title=”2011-10-27″ when text says ‘27 Oct 2011’.
Google’s Webmaster area has a rich snippet page that tells you how they want you to mark up data, and what’s most likely to be pulled into the search results. Not all data are pulled into the SERPs at the moment, but as more may be used in the future it makes sense to mark up as much as possible.
Best thing to do to help is to use Google’s rich snippets testing tool – this gives an example of how how it looks your page could look in the SERPs and shows the data it’s parsed.
There are compound microformats (microformats with microformats nested inside them). For instance hRecipe can hold an aggregated review and author.
To mark up an author, link all recipes (or articles) to a profile page using rel=author, then link form the profile page to a Google profile with rel=me. See the Google Webmaster Tools help page on authorship.
Does this affect SEO? Google are not telling us – Glenn suspects it does affect ranking but doesn’t know.
Audience Question: there’s spam going on with microformats, how do you avoid it?
Glenn says it does happen: people will game any technique that affects search listings. It will be the usual cat-and-mouse game between Google and spammers. Microformats are about adding extra semantic data to website, improving way machines can parse information: quality content will win out in the end.
Pierre Far from Google said that if someone’s rich snippet spam really affects the SERPs, Google will take their rich snippets out. There’s a form to report rich snippet spam. Don’t abuse it.
Audience Question: Unlike other attributes, rel=author is tied into Google+, so does it belong to google? Will it be able to tie into other social profile sites to be used by Bing and others?
Glenn hopes Google will become more open, as people are interested in connecting up social media identities.