What is Linked Data?

Sir Tim Berners-Lee on Linked Data

Linked Data is a set of simple principles for publication of data on the Web. The use of Linked Data principles allows you to publish data in a more meaningful and reusable way.

At the heart of the Linked Data approach is the notion of the Universal Resource Identifier, or URI for short. URIs are standard Web technology: each web address is a URI, so each document on the Web is already reachable via a URI. Applying this principle to data means that we assign a URI to each specific data item, instead of just publishing a static document (such as an Excel spreadsheet or a PDF report).

This approach has a number of benefits when compared to publishing data in a static document:

  • fine-grained access
    When you publish your data via a Linked Data API, data consumers can pose requests for each individual data item, rather than having to download the entire static container. This enables data consumers to run their applications directly on your live published data and avoids conflicts and the proliferation of outdated and incorrect information.
  • powerful querying and integration/mashing
    Linked Data implies that your data is integrated with other data sources. Your data can reuse URIs from other sources (for example, URIs for locations), and other sources in turn can reuse your URIs, analogous to how websites link to each other to provide further related information. A linked data service enables data consumers to perform powerful queries, slicing your data any which way to provide new insights.
  • structure and context
    Because each data item is individually addressable, providing contextual information about that data item becomes easy. It can be qualified, annotated, and explained, facilitating correct interpretation of the data by the consumer.

Who already uses Linked Data?

The LOD cloud diagram

The Linked Data Cloud diagram, by Richard Cyganiak and Anja Jentzsch. source: http://lod-cloud.net(click to zoom)

The collection of interlinked data sets published according to Linked Data principles is known as the Linked Data Cloud, and is an ever growing global source of information.

Linked Data technology is used extensively by various open government data projects throughout the world, most notably the UK government as well as the US government.

In addition, Linked Data technology is employed by many businesses and private institutions, including for example the New York Times, the GeoNames project, and the BBC.

Want to know more?

Good starting points for learning more about the technical aspects of linked data are linkeddata.org and the W3C Semantic Web activity. Alternatively, get in touch. Rivuli provides introductory talks and workshops, and I am happy to talk with you and see if linked data is right for your organization.