1 Semantic Web Technologies for UK HE and FE Institutions: Part 1: Background to the Development of the Web Brian Kelly UK Web Focus UKOLN

2 Background Brief History of the Web: 1991Tim Berners-Lee invents Web at CERN. Web consists of three architectural components: data format (HTML), addressing (URIs) and transport (HTTP) 1993Early adopters in UK HE begin evangelising (to an initially sceptic audience) 1995Web seen as the killer app in UK HE (farewell to Gopher, home-grown info systems, …) Who can remember the excitement caused when the Web first appeared? "You mean I just have to click here and this Virtual Frog appears from the US? It's magic" Also notice the short time it took to become mainstream. Who can remember the excitement caused when the Web first appeared? "You mean I just have to click here and this Virtual Frog appears from the US? It's magic" Also notice the short time it took to become mainstream.

3 The Web Grows Up The Web: Initially simple to understand and easy to deploy  Limited in functionality, expensive to maintain, … So we see rapid developments in core architecture: CSS: simple separation of structure and content. You must be using CSS – no argument, just some implementation issues. XML: the killer meta-language for creating languages. XML must be the key format for your IT strategy – no argument, just some implementation issues. SVG, SMIL, MathML: examples of 'cool' formats being developed in W3C, with many other formats being developed elsewhere (e.g. OASIS) XHTML 2.0: Will allow us to escape from the mess caused by non-compliant HTML/XHTML 1.0 documents (XHTML 2.0 must be compliant)

4 More On XML XML is more than just a meta-format for creating other formats: XSLT: Enables XML resources to be converted to other formats (other XML languages or other formats such as PDF) XLink, XPointer,...: Address the limitations of the hypertext model in the initial Web (e.g. embed link into existing document; link to the 2nd-4th bullet point; …) XML Schemas: Define structure and constraints of XML documents XML Namespaces: Allow XML documents to be merged without problems caused by name clashes (e.g. of document, of person, of book, …) …

5 More The Just Documents XML: Can be used to define protocols (rules) and not just document formats Is at the heart of "Web Services" – a Web-based infrastructure for allowing computers to communicate with computers in a rich way Key aspects to Web Services: SOAP: An XML-based protocol for communications between computers WSDL: An XML-based description of a Web Service UDDI: A mechanism for finding Web Services … Web Services is about connecting computers

6 But XML Isn't Enough … But XML still has its limitations: George Orwell 1984 … An XML record George Orwell 1984 … An XML record How will an automated tool know that these records (and ones in other languages) are similar? Coding transformations into the automated tool is not a scalable solution How will an automated tool know that these records (and ones in other languages) are similar? Coding transformations into the automated tool is not a scalable solution

7 RDF – XML To The Rescue! The solution to this problem is: To use an XML To embed some form of magic into the XML tags The XML application is called RDF RDF is at the heart of the Semantic Web Encoding magic Into an XML record George Orwell 1984 … The magic isn't, in fact, magic, but a simple mathematical expression which enables data to be integrated with data from other sources together with use of URIs. The Semantic Web is about connecting data

8 Semantic Web Technologies for UK HE and FE Institutions After several years of discussion about the Semantic Web and RDF much architectural work has been done and we are now beginning to see interesting Semantic Web applications. So let's now hear about: How RDF actually works How RDF and the Semantic Web relate The potential for Semantic Web technologies in UK HE and FE institutions