What is Linked Data? The recent LinkedData Planet conference in NYC marked, I think, a real transition point. The conference signaled the beginning movement of the Linked Data approach from the research lab to the enterprise. As a result, there was something of a schizophrenic aspect at many different levels to the conference: business and research perspectives; realists and idealists; straight RDF and linked data RDF; even the discussions in the exhibit area versus some of the talks presented from the podium. Like any new concept, my sense was a struggle around terminology and common language and the need to bridge different perspectives and world views. Like all human matters, communication and dialog were at the core of the attendees’ attempts to bridge gaps and find common ground. The reality, of course, is that Linked Data is still very much in its infancy, and its practice within the enterprise is just beginning. Linked Data Defined All references to Linked Data below embrace this definition. 1. Yes.
Linked Data and URI:s for Enterprises Why Carry the Cost of Linked Data? – Tom Heath’s Displacement Activities June 16th, 2010 by Tom Heath In his ongoing series of niggles about Linked Data, Rob McKinnon claims that “mandating RDF [for publication of government data] may be premature and costly“. The claim is made in reference to Francis Maude’s parliamentary answer to a question from Tom Watson. There’s nothing premature about publishing government data as Linked Data – it’s happening on a large scale in the UK, US and elsewhere. Let’s make a direct comparison between publishing a data set in raw CSV format (probably exported from a database or spreadsheet) and making the extra effort to publish it in RDF according to the Linked Data principles. Oh wait, you’ll need to write some documentation explaining what each of the columns in the CSV file mean, and what types of data people should expect to find in each of these. So what are the comparable processes and costs in the RDF and Linked Data scenario? Clearly these extra steps come at a cost compared to publishing raw CSV files.
Welcome — LOD2 – Creating Knowledge out of Interlinked Data How to publish Linked Data on the Web This document provides a tutorial on how to publish Linked Data on the Web. After a general overview of the concept of Linked Data, we describe several practical recipes for publishing information as Linked Data on the Web. This tutorial has been superseeded by the book Linked Data: Evolving the Web into a Global Data Space written by Tom Heath and Christian Bizer. This tutorial was published in 2007 and is still online for historical reasons. The Linked Data book was published in 2011 and provides a more detailed and up-to-date introduction into Linked Data. The goal of Linked Data is to enable people to share structured data on the Web as easily as they can share documents today. The term Linked Data was coined by Tim Berners-Lee in his Linked Data Web architecture note. Applying both principles leads to the creation of a data commons on the Web, a space where people and organizations can post and consume data about anything. This chapter describes the basic principles of Linked Data.
Introduction to Linked Open Data for Visualization Creators on Datavisualization Introduction to Linked Open Data for Visualization Creators Last week ReadWriteWeb asked: “Is Linked Data Gaining Acceptance?” Our answer: definitely yes. But you don’t have to stop there! Back in 2001 Tim Berners-Lee and his collaborators published a seminal article called “The Semantic Web” in which they presented their idea of “a new form of Web content that is meaningful to computers [and] will unleash a revolution of new possibilities”. First up is the term Semantic Web. One technological concept that is part of the Semantic Web vision is Linked Data, which describes “a method of publishing structured data, so that it can be interlinked and become more useful” (Wikipedia). The meaning of “a populated place” in this case is clearly defined, so that others can look up what it means exactly and also use this definition themselves. Linked Data by itself doesn’t have to be publicly available data, it can just as well be used in private, so we need one more definition: Open Data.
Online Access Overview The following interfaces exist for online access: Rest Api: provides basic access to a database with a full Open Street Map (OSM) planet file loaded. Sparql Endpoints: enable queries on databases with a reduced (but hopefully for many applications relevant) subset of the whole data loaded. The Sparql Endpoints come in two flavours: Static: Contains the data extracted from a OSM planet file of a certain date Live: Initially a copy of the static version that is then synchronized with the minutely updates from OSM. As of 2012 February 1st, the Virtuoso database powering the live SPARQL endpoint is not synchronized anymore. A summary of the capabilities of the interfaces are given below. Features Access to all nodes and ways and their tags of a planet file. Retrieval of data within circular and rectangular area Note: the underlying database is being synchronised with OSM. Sparql Endpoints
A skim-read introduction to linked data Linked Data | Linked Data - Connect Distributed Data across the Web