What is Linked Data?
Linked data is a method for publishing structured data using vocabularies like schema.org that can be connected together and interpreted by machines. Using linked data, statements encoded in triples can be spread across different websites.
Linked Data Examples
How does Linked Data works? This simple example will help you understand how linked data conveys concepts and connections.
Let’s say that on Website A we can present the entity Jason and the fact that he knows Marie. On website B we can provide all the information about Marie and on the Website C we can find information about Marie’s birthplace.
Each page contains the structured data to describe an entity (Jason, Marie and Italy) and the link to the entity that could be described on a different page or even on a different website.
Below, you can find a real-life example of the linked open data graph visualization from the website of our client, Salzburgerland Tourism.
What is the role of Linked Data?
Back in 2006 Tim Berners-Lee described linked data as follows:
The Semantic Web isn’t just about putting data on the web. It is about making links, so that a person or machine can explore the web of data. With linked data, when you have some of it, you can find other, related, data.
In computing linked data describes a method of publishing and linking data coming from heterogeneous data sources that can be interlinked and shared.
Linked Data builds upon standard Web technologies such as HTTP and URIs, but rather than using them to serve web pages for human readers, it extends them to share information in a way that can be read automatically by computers. This enables data from different sources to be connected and queried.
Queries over linked data are made using a semantic query language called SPARQL that allows to retrieve and manipulate data stored in Resource Description Framework (RDF) format.
Learn how we got to the Linked Data in SEO and why you need to build a Knowledge Graph side-by-side with your website to stand out in search results by reading our article.
Linked Data Explained
This great introduction video on linked data, the Google Knowledge Graph and Facebook Open Graph protocol was done by @manusporny.
Why is it Important to Publish 5-stars Linked Data?
Tim Berners-Lee suggested a 5-star deployment scheme for Open Data. Below, you can find examples for each grade in order to understand why publishing 5-stars linked data is so important:
★ Make your content available on the web with an open license.
★★ Make your content available as machine-readable structured data (e.g., Excel instead of an image scan of a table). If you’re using WordLift, you will also be able to enrich your structured data with more related pieces of information, the so-called properties.
★★★ Make your content available in a non-proprietary open format (e.g., CSV instead of Excel).
★★★★ Assign a unique and permanent URl to each entity to identify them and to make your content easily findable by people using stable IDs.
★★★★★ Link your data to other data to provide a context: now the web is connected and you’ve reached the 5th star.
Linked Data Principles
There are four simple principles to follow when publishing data on the web (and yes, structured data is linked open data as it is fully accessible).
- Use URIs as names for things (this is the unique identifier that we introduced above)
- Use HTTP URIs so that people can look up those names (this means that the ID of every entity shall be accessible via HTTP URI)
- When someone looks up a URI, provide useful information, using the standards (Behind these URIs we need to publish data using a linked data standard called RDF)
- Include links to other URIs. so that they can discover more things (and here is where we need to add owl:sameAs property).
To put it simply, a 5-stars open dataset is simply a way to publish metadata (using linked data standard) that makes it readable and accessible by machines.
That is why by connecting a piece of text, written by a human with an open dataset created by a machine, our content becomes fully accessible and machine-friendly.
Some of the primary datasets that implement the 5-stars linked data schema are foundational for the machine learning algorithms behind semantic search engines like Google and Bing as well as digital personal assistants like Alexa, Cortana, and the Google Assistant.
These datasets (like DBpedia, Wikidata, Geonames just to name it a few) are all interlinked together to form a Linked Open Data Cloud.
When you add structured data to your WordPress website using a plugin like WordLift, that structured data gets published as open linked data. In short, your WordPress website, and the metadata of your own content becomes part of that Linked Open Data Cloud. Thus by adding an additional layer to the Semantic Web your WordPress website also becomes part of it!
Read more on what the Linked Open Data Cloud is and how to add your datasets.
How WordLift creates Linked Open Data out of a Website
WordLift publishes your content as Linked Open Data. We have created a simple workflow for online publishers, bloggers, business owners and editorial teams to democratize semantic technologies. With our software, anyone can build optimized knowledge graphs for content publishing, search engine optimizationoptimisation and semantic search.
Want to know more? Here’s how to make your own SEO-friendly Machine-Readable Entity.