Including schema microdata in your web pages is a lot like eating well, exercising or getting a good night’s rest – you know you should be doing it, but actually following through can be harder than it sounds. Unless you’re a health nut, in which case please stop telling us about Crossfit.
Although schema and other structured markup formats have been around for several years, relatively few sites bother to include schema microdata, and even fewer people actually know what schema is or what it’s for. However, there’s no need to be embarrassed – we’re going to answer your questions about schema and why you should make it an integral part of your SEO strategy . Pay attention – there’s a test at the end*.
What is Schema?
Schema is a type of microdata that makes it easier for search engines  to parse and interpret the information on your web pages more effectively so they can serve relevant results to users based on search queries.
What is Schema.org?
Schema.org  is the centralized home on the web for the Schema project, a collaboration between Google, Bing, Yahoo! and Russian search engine Yandex (the one trying out search without link s) to standardize structured markup.
How Does Schema Work?
As with other markup formats, schema microdata is applied to the content of a page to define exactly what it is and how it should be treated. Schema elements and attributes can be added directly to the HTML code  of a web page to provide the search engines’ crawlers with additional information.
In the example below from schema.org, which focuses on content about James Cameron’s 2009 movie, “Avatar”, you can see that adding the
itemtype attribute to the relevant
<div> block makes it easier for search engines to identify that this content relates to a movie, as defined by the schema.org type hierarchy . Similarly, the addition of the
itemscope attribute specifies that everything contained in that particular
<div> block references a specific item – in this case, James Cameron’s $237 million remake of “Fern Gully.”
Let’s look at another example from schema.org:
Times and dates can be very difficult for search engines to interpret correctly. This is due to differences in how dates are formatted, whether the event in question took place in the past or is scheduled to occur in the future, and the fact that search engines (like all computers) are actually pretty stupid. In this example, the inclusion of the
Event itemtype attribute makes it clear that this is an event taking place on a specific date (as you can see by the addition of the
datetime attributes), making it easier for search engines to return relevant results  to the user. This eliminates any ambiguity for users searching for information about the 1984 film of the same name, which is arguably one of the finest movies ever made. Unlike “Avatar.”
Can Schema Improve SEO?
Including schema microdata in your HTML code can help search engine crawlers interpret the content of your pages more effectively. This, in turn, can increase your visibility . However, it’s important to note that including schema (or any other structured markup format) in your code is not a quick and dirty SEO “hack” – instead, think of schema as a best practice to make it easier for search engines to find and display your content.
Does Schema Improve Search Rankings?
No, not at this time. Google claims that the inclusion of schema microdata is not currently used as a ranking signal . However, it does improve your site’s rich snippets, which can help your site appear more prominently in SERPs.
What Else Can Schema Do for Me?
Aside from making it easier for search engines to properly categorize your site’s content, marking up your pages with schema microdata can also be used to define and display rich snippets  of your content in SERPs. Contrary to common misconception, Google does in fact use schema markup to display rich snippets. Clear, concise rich snippets can result in higher click-through rates , as users can quickly and easily determine whether the content on your site is what they’re looking for.
Image credit: Google 
How Do I Markup My Pages with Schema Microdata?
Okay, I’ll level with you – marking up your pages with schema microdata can be kind of a pain, especially if your site has hundreds (or thousands) of pages. The markup has to be added manually to each page, which is a lot of work for larger sites. However, if you’re still in the planning stages or have a smaller site (lucky you), then adding schema microdata will be less hassle. Follow the steps outlined in this guide  to get started. Once you’re satisfied with your markup, use Google’s Structured Data Testing Tool  to check that everything is working correctly.
Do I Have to Markup Every Property on Every Page?
No, but the more properties you apply schema microdata to, the clearer the nature and purpose of your site’s content will be to the search engines. Also, it’s worth remembering that you have to apply schema markup to a certain number of properties before Google can create rich snippets using your microdata. You can check what information can be extracted from your markup using Google’s Structured Data Testing Tool.
What About Facebook Open Graph and Twitter Cards?
Some marketers mistakenly believe that including Open Graph tags (and Twitter Cards, to a lesser extent) is all they need to do to ensure that their content is as shareable as possible. However, schema microdata can be used in conjunction with social media  tags to provide search engines with even more detail about a page’s content. Include schema markup alongside your Open Graph tags to make your content shareable and highly optimized.
Does Schema Support Other Markup Data Types?
Yes. When Google announced the schema.org project, a lot of webmasters were dismayed to learn that information types supported by other structured markup formats weren’t compatible with schema microdata. Google listened, and now schema plays nice with data types featured in RDFa and other formats.
Can I Add to the Schema Vocabulary?
Kind of. Schema’s type hierarchy contains many commonly used item types. Most have relevant subtypes, but the extent of these subtypes can vary. In some cases, you might want to add your own item types to your markup. You can do this by using extensions. To create a custom item type, simply add a slash at the end of an existing item type, and enter the new term.
In the example above,
Person is the existing itemtype, while
ElectricalEngineer are the custom item types. Details about naming conventions and extending existing properties, classes and enumerated items can be found on schema.org .
Do you use schema microdata or another type of markup format? If not, why not? Let us know in the comments!