This, 2009, is the year linked data is being heralded as a treasure map as early adopters offer some very interesting pointers on how we can browse, explore, query and re-use data on the Web at a more fine-grained level in exciting new ways. "We are already seeing examples of non-personal public data through initiatives spearheaded by the U.S. and UK governments. Other countries will follow suit. This will be one of the tipping points for the growing web of linked data and the increasing number of applications to exploit the data sets", says Professor Dame Wendy Hall, one of the pioneers of the Semantic Web from the University of Southampton, speaking from the Online Information conference in London in early December.
Putting government data online means increasing citizen awareness of government functions for greater accountability and enables the government to function more efficiently. The UK’s new policy for public data has been triggered by pioneering work in the arena of linked data in a relatively short time-frame.
“Available public data creates bottom-up pressure to improve public services. Data is essential in enabling citizens to choose between public service providers, helping them compare their local services with services elsewhere and enables all of us to lobby for improvement”, says Nigel Shadbolt, a co-pioneer of the Semantic Web, also from the University of Southampton. data.gov.uk, a developer’s version of the government website that will be made public early next year, currently gives access to 1100 datasets ranging from traffic counts on the road network, reference data on schools and the Farm Survey, illustrating the future growth potential in the step-change towards the Web of Data, or Semantic Web, encompassing technology development, politics, economics and social change.
Linked data principles provide a basis for realising the Web of Data by ensuring data is organised, structured and independent of any application programmes so it can serve a broad community of people and many applications. The main drivers behind linked data include the value-add of structured content, a mission or mandate to make data linkable and most importantly low development barriers. Key enabling technologies span Web2.0, Mash-ups, Open Source, Cloud Computing and Software-as-a-Service.
Is it complicated? Not particularly. As Ian Davis, CTO at Talis explained "What is needed is a little extra effort when publishing data through the Resource Description Framework (RDF), the HTML of data web. This is done by giving each thing an identifier or Uniform Resource Identifier (URI), just as we do with web pages. The next step is to describe these things using RDF with links to other information so as to provide a context and respond to requests on identifiers by sending the description of that thing. No special software is needed to use it. When we turn a site into an API using linked data, people can start building new things reusing data in new and interesting ways”.
The BBC programme catalogue and their music site is a good example of linked data in action. Every BBC programme, segment of a programme, every brand and every person has an identifier, a URI, with the data hidden behind the page displayed on the screen. But it doesn’t stop here. Linked data from the BBC programme pages are remixed on Twitter through fanhu.biz, a prototype service, creating a social space for fans of BBC programmes. While many of the early use sites are read-only, linked data can also be used for powerful fully interactive web applications with full editing capabilities thanks to this very flexible technology.
"The Semantic Web will transform the World Wide Web into a more useful and powerful information source. In particular it will revolutionise scientific and other web publishing by defining new web technologies that make more web content accessible to machines. These technologies will provide better tools that make it easier for people to create machine-readable content that is widely available. A good case in point is an initiative spearheaded by the Association for Computing (ACM), the world’s leading educational and scientific computing society. In early 2010 Semantic Web tools will be implemented in the ACM Digital Library (http://portal.acm.org/dl.cfm) to enable its hundreds of thousands of professional and student users to more easily find, share, and combine information on the Web”, said Dame Wendy .
How will the Web of Data evolve? For now we only have clues on the direction Web3.0 will take in the next few years, when we can expect to see linked data services available on iPhones and mobile devices and new business models emerge. While there are still some open questions as to what tools are needed, the Semantic Web will emerge and it will probably be a hybrid of data and documents side by side. How they will co-exist is the fruitful line of research and development. “We believe that linked data will be an even bigger sea change than the world wide web not only because it plays a key role in assisting a wide range of people in government and research but also socially. With linked data it will be much easier to tackle grand global challenges like climate change, energy and health issues, ageing, and world poverty by sharing data to capture correlations and trends more effectively and more quickly and spot clues that enables someone to make that all-important step forward. The key thing is to arrive at universal standards just as we did with the web, understand that attitude is as important as the technology to get critical mass that will boost innovation and that linked data means lots more innovation", explained Dame Wendy, who also serves as President of ACM, the first person from outside North America to hold this position.
Some of the early adopters have already started to unleash information that is of value socially, politically and economically. Looking ahead, other important areas creating a treasure map for online information could include globally aggregated services on university courses encompassing league tables and citations and even a global index for a world library collection, bringing fantastic new opportunities for knowledge information professionals, who already have the skill sets needed to understand data management issues and in some instances of using metadata to describe the data in their collections, a rich information source for linked data. The bottom-line is that this is an evolution and not a replacement of the Web and that future-gazing is part and parcel of being involved in bleeding-edge technologies.