The Semantic Web Vision

Course Work Dr Yasser Fouad Blogs.alexu.edu.eg 2

3 The Semantic Web “The Semantic Web is an extension of the current web in which information is given well- defined meaning, better enabling computers and people to work in co-operation.“ [Berners-Lee et al, 2001]

4 Today’s Web Currently most of the Web content is suitable for human use. Typical uses of the Web today are information seeking, publishing, and using, searching for people and products, shopping, reviewing catalogues, etc. Dynamic pages generated based on information from databases but without original information structure found in databases.

5 What is a Web of Data? Thinking back a bit HTML and URIs Markup language and means for connecting resources Below the file level Stopped at the text level [Miller 04]

6 Web 2 It is all about people, collaboration, media,... [The mind-map pictured above constructed by Markus Angermeier, source Wikipedia]

7 Web 2.0 and Folksonomies [

8 Semantic Web Content: New “Users” applications agents

9 What is a Web of Data? (continued) Now XML, RDF, OWL and URIs Markup language and means for connecting resources Below the file level Below the text level At the data level [Miller 04]

10 Semantic Web: Resource Integration Shared ontology Web resources / services / DBs / etc. Semantic annotation

11 Web resources / services / DBs / etc. Shared ontology Web users (profiles, preferences) Web access devices Web agents / applications External world resources Smart machines and devices Industrial and business processes Semantic Web: which resources to annotate ? Multimedia resources

12 Keyword-Based Search Engines Current Web activities are not particularly well supported by software tools – Except for keyword-based search engines (e.g. Google, AltaVista, Yahoo) The Web would not have been the huge success it was, were it not for search engines

13 Today’s Web

14 Problems of Keyword-Based Search Engines High recall, low precision. Low or no recall Results are highly sensitive to vocabulary Results are single Web pages Human involvement is necessary to interpret and combine results Results of Web searches are not readily accessible by other software tools

15 The Key Problem of Today’s Web The meaning of Web content is not machine- accessible: lack of semantics It is simply difficult to distinguish the meaning between these two sentences: I am a professor of computer science. I am a professor of computer science, you may think. Well,...

Machine Accessible Meaning CV name education work private

17 The Semantic Web Approach Represent Web content in a form that is more easily machine-processable. Use intelligent techniques to take advantage of these representations. The Semantic Web will gradually evolve out of the existing Web, it is not a competition to the current WWW

History of the Semantic Web Web was “invented” by Tim Berners-Lee (amongst others), a physicist working at CERN TBL’s original vision of the Web was much more ambitious than the reality of the existing (syntactic) Web: TBL (and others) have since been working towards realising this vision, which has become known as the Semantic Web – E.g., article in May 2001 issue of Scientific American… “... a goal of the Web was that, if the interaction between person and hypertext could be so intuitive that the machine-readable information space gave an accurate representation of the state of people's thoughts, interactions, and work patterns, then machine analysis could become a very powerful management tool, seeing patterns in our work and facilitating our working together through the typical problems which beset the management of large organizations.”

Where we are Today: the Syntactic Web [Hendler & Miller 02]

What information can a machine see…                          

Solution: XML markup with “meaningful” tags?                        …

22 Just for case you do not know: Introduction to XML

23 Internet and World Wide Web Code: G52IWW Students: Undergraduate Internet and World Wide Web Code: G52IWW Students: Undergraduate HTML: Internet and World Wide Web G52IWW Undergraduate XML :  User definable and domain specific markup

24 XML: Document = labeled tree module lecturertitlestudents nameweblink... =  DTD: describe the grammar and structure of permissible XML trees  node = label + contents

25 Semantic Technology Market Forecasting Semantic solution, services & software markets will grow rapidly, topping $60B by 2010.

26 The Semantic Web Impact – Knowledge Management Knowledge management concerns itself with acquiring, accessing, and maintaining knowledge within an organization Key activity of large businesses: internal knowledge as an intellectual asset It is particularly important for international, geographically dispersed organizations Most information is currently available in a weakly structured form (e.g. text, audio, video)

27 Limitations of Current Knowledge Management Technologies Searching information – Keyword-based search engines Extracting information – human involvement necessary for browsing, retrieving, interpreting, combining Maintaining information – inconsistencies in terminology, outdated information. Viewing information – Impossible to define views on Web knowledge

28 Semantic Web Enabled Knowledge Management Knowledge will be organized in conceptual spaces according to its meaning. Automated tools for maintenance and knowledge discovery Semantic query answering Query answering over several documents Defining who may view certain parts of information (even parts of documents) will be possible.

29 The Semantic Web Impact – B2C Electronic Commmerce A typical scenario: user visits one or several online shops, browses their offers, selects and orders products. Ideally humans would visit all, or all major online stores; but too time consuming Shopbots are a useful tool

30 Semantic Web Enabled B2B Electronic Commerce Businesses enter partnerships without much overhead Differences in terminology will be resolved using standard abstract domain models Data will be interchanged using translation services. Auctioning, negotiations, and drafting contracts will be carried out automatically (or semi-automatically) by software agents

Wikis Collections of web pages that allow users to add content via a browser interface Wiki systems allow for collaborative knowledge Users are free to add and change information without ownership of content, access restrictions, or rigid workflows 31

Some Uses of Wikis Development of bodies of knowledge in a community effort, with contributions from a wide range of users (e.g. Wikipedia) Knowledge management of an activity or a project (e.g. brainstorming and exchanging ideas, coordinating activities, exchanging records of meetings) 32

Semantic Web Enabled Wikis The inherent structure of a wiki, given by the linking between pages, gets accessible to machines beyond mere navigation Structured text and untyped hyperlinks are enriched by semantic annotations referring to an underlying model of the knowledge captured by the wiki − e.g. a hyperlink from Knossos to Heraklion could be annotated with information is located in. This information could then be used for context-specific presentations of pages, advanced querying, and consistency verification 33

34 Book Outline 2. Structured Web Documents in XML 3. Describing Web Resources in RDF 4. Web Ontology Language: OWL 5. Logic and Inference: Rules 6. Applications 7. Ontology Engineering 8. Conclusion and Outlook