by Stephanie Parker
"I have a dream for the Web in which computers become capable of analysing all the data on the Web", said Tim Berners-Lee in 1999. Therein lay the future. Linked Data is part of the vision of the semantic web to enrich the structure of the Web by embedding semantic annotations into data to improve the quality of search, collaboration, publishing and advertising and enable applications to become more integrated and intelligent.
Initiatives recently spearheaded by the UK and U.S. governments to make non-personal public data available online are aimed at increasing accountability and raising awareness of government functions among citizens. Linked Data is a way of making that information available easily and efficiently. In general, it is open, modular and scalable. Because linked data is expressed in open, non-proprietary formats it is accessible through an unlimited variety of applications. This can also be combined (mashed-up) with other pieces of linked data, with the option of adding more to existing data even when the terms and definitions used change over time.
The Resource Description Framework (RDF), a W3C standard for describing resources in the Web and a major component in what is proposed by the W3C for the Semantic Web, serves as the "interconnection bus" for current data formats. One of the distinguishing features of the linked data technology is that it allows data communication to be composed of mixed vocabularies, which come from a community, be it local, state, national or international. RDF uses Uniform Resource Identifiers (URIs) to allow the linking of things and concepts. The URI thus helps identify a resource on the internet, enabling interaction with representations of the resource over a network using specific protocols. RDF also allows interoperability to be added wherever this is cost-effective.
"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", said Professor Dame Wendy Hall, University of Southampton.
Digital Libraries can benefit from RDF to facilitate digital resource management and support knowledge management for an interoperable information environment like that found in a digital library (DL). A good case in point is the Digital Library of the Association for Computing Machinery (ACM), the world’s largest, most comprehensive and respected on-line resource in the field of computing, which is due to adopt RDF in 2010. Providing the full text of every article from every journal, magazine, conference proceedings, newsletter, oral history interview and video published since 1954, the ACM Digital Library has been at the forefront of technology since its inception. “The introduction of Semantic Web tools in the ACM Digital Library will enable its hundreds of thousands of professional and student users to more easily find, share, and combine information on the Web", explained Dame Wendy Hall, President of ACM.
The potential for RDF is huge. Media and publishing are among the early adopter sectors with use cases from the BBC and The New York Times, which refers to its Linked Data as its "Treasure Map". Life science publishers have also adopted this model and cutting-edge research, information on climate change and academic publishers are all beginning the transition. All these early use cases are demonstrating new ways to manage and discover information. The ultimate goal is to make semantic web mainstream and enable information professionals through dedicated courses. Some of the challenges involve the security architecture of data, which can be best addressed by learning from lessons in the past.
"Linked data could 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”, said Dame Wendy Hall. 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, spotting clues that enable researchers to make that all-important step forward. Dame Wendy Hall remarked, “Linked Data means lots more innovation but attitude is as important as the technology to get critical mass. The key thing is to arrive at universal standards just as we did with the web".
The Semantic Web is not a separate web but an extension of the current one. The UK government’s recently announced plans to create a new institute for Web Science with Tim Berners-Lee at its helm and hosted by Oxford and Southampton universities, means that the vision is now a step closer. Imagination is our only barrier.
Online Information Conference, 1-3 December 2009, London – keynote by Wendy Hall and Nigel Shadbolt, University of Southampton. W3C – RDF and on-line government data Podcast at http://2009.online-information.co.uk/online09/podcasts.html