The current web represents information using natural language, graphics, multimedia, page layout etc. Humans can process this easily and can deduce facs from partial information, can create mental associations that are used ... slide based tutorial on the semantic web

The Semantic Web lies at the heart of Tim Berners-Lee's vision for the future of the World Wide Web. Along with others at the W3C Berners-Lee is working on the infrastructure for this next stage of the Web's life. But the question "What is the Semantic Web?" is being asked with increasing frequency. While mainstream media is content with a high level  more

Semantic Technologies are designed to extend the capabilities of information on the Web and enterprise systems to be networked in meaningful ways. The adoption of World Wide Web Consortium (W3C) standards like XML, RDF (Resource Description Framework) and OWL (Web Ontology Language) serve as foundation technologies to advancing the adoption of semantic technologies. more

Semantic Web Technologies

Definition: Semantic Web Technologies is an umbrella term used to describe both the infrastructure and services provided by the Semantic Web, a framework that allows software applications to automatically discover, access and execute web services.


Semantic web technology

One of the largest problems in the development of IT systems within an enterprise is integration between applications. Even today, there are few integration standards used by software developers to allow their applications to effectively communicate with third party software. The inevitable result is that enterprise IT systems are cobbled together, inefficient hulks – and IT budgets are drained in an effort to find some way of integrating multiple disparate systems.

Development of SOA and Web Services

In an effort to alleviate these problems and their associated costs, software developers and organisations such as the World Wide Web Consortium (W3C) worked to design a number of standards by which software applications could become interoperable.

The result of this was the development of Service-oriented Architecture (SOA), a collection of interoperability standards that allow loosely coupled software services to interconnect, regardless of platform or operating language.

Furthermore, markup languages such as XML (and XML-based formats such as SOAP and WSDL) extended this ability to include web services, allowing applications to exploit services over the Internet.

Development of the Semantic Web

Though the development of XML and its various formats was an important advance in the development of interoperable web technology, the limitations of the language are all too evident.

The primary problem is that XML is not descriptive enough about the information it describes for it to be adequately computer-understandable. While the foundations for connectivity have been laid out in SOA standards and XML, there remains the simple problem that, though computers can discover services and connect to them, they have no way of understanding what these services actually do. For that we require a new language.

Semantic Web Technologies

In an effort to enable computers to understand semantic web services there have been developed several technologies that will pave the way, including Resource Description Framework (RDF) and Web Ontology Language (WOL).

RDF is a metadata model (typically based on XML) that assigns data with a semantic metadata description that can be understood by computers. The RDF model is based on the RDF ‘triple’, a method of describing data using a ‘subject-predicate-object’ expression.

For example, a computer would have no way of understanding the statement ‘The couch has the colour red’, as computers cannot use semantics to draw conclusions as to its meaning. However, by describing the statement as ‘subject-predicate-object’ it is possible to tell the computer what the statement means:

‘The couch’ = subject

‘has the colour’ = predicate

‘red’ = object

Based on these metadata, a computer could now infer the meaning of the complete statement, rather than simply recognising the words themselves.

Applications in Web Services

The various semantic web standards (such as RDF and OWL) add an extra layer on top of syntactic data to provide computers with a method to understand the semantics of information. The implications this will have for web services are potentially enormous.

By providing computers with the means to understand the information held on the Internet the online experience could become a single mashup – that is, an application that draws data from multiple locations and presents them seamlessly in a single application. Computers could scour the Internet for relevant data and present it automatically to our desktop computers.

Clearly this would be a great development in personal computing, allowing users to set their personal preferences and entrust the computer to gather information they’re interested in. However, it could have an even greater impact on business.

The Internet represents the largest repository of information on earth. Unfortunately, the volume of data and the way in which it is presented prevents us from effectively capitalising on that information at present. The development of the Semantic Web will enable computers to automatically gather valuable data from hundreds – or even thousands – of web services, presenting them to the user for analysis.

With developments in semantic web technology, it seems the days of manual browsing could be numbered. In the future, there may be no need to deal personally with the Internet at all. We will instead use semantic web applications as our window to the web.

Further information regarding semantic web technologies can be found at the University of Southampton (pdf), the Open University and CETIS.