By Ahmet Can Babaoğlu Abdurrahman Beşinci

 Suppose you want to buy a Star wars DVD having such properties;  wide-screen ( not full-screen )  the extra disc of bonus materials  lowest available price  not paying too much for shipping and handling  not waiting too long for delivery. What would you do?  The best thing you can do is to search for web pages and look for a suitable item.  However, using semantic web, agents can return the suitable results to you…

 An agent lists the prices of flat screen HDTVs with properties;  larger than 40 inches with 1080p resolution  at shops in the nearest town  open until 8pm on Tuesday evenings  Find and buy a airline ticket if there is a route from Istanbul to London this evening with price lower than $150

Tim Berners-Lee (1998 )  Inventor of WWW, URIs, HTTP, and HTML  The director of the World Wide Web Consortium ( )  Senior researcher at the MIT Computer Science and Artificial Intelligence Laboratory

A Web that includes  documents, or portions of documents,  describing explicit relationships between things and  containing semantic information intended for  automated processing by our machines. TBL’s words; Now web is a huge book, with semantic web, it will be a huge database. A technology helps machines `understand`; ◦ The Beatles was a popular band from Liverpool. ◦ John Lennon was a member of the Beatles.

 Machine process-able  Data integration  Meaningful web pages  Making deductions  SW is not AI and AI is not SW SW should be a great playground for AI

 Web of data - provides common data representation framework to facilitate integrating multiple sources to draw new conclusions  Increase the utility of information by connecting it to its definitions and to its context  More efficient information access and analysis

Agents searching Web and retrieving valuable information to the end user. Web services publishing their information Programs running to merge data of different web services and create new results from them.

 User: Exciting world - semantics of the resource, understood from content  Machine: Very little information available, only links

 User: Even more exciting world, richer user experience  Machine: More processable information is available (Data Web)

 Metadata layer ( Resource and property ) RDF ( Resource Description Framework )  Schema layer ( Hierarchical description of concepts ) RDF-S ( RDF Schema )  Logical layer ( class relations, uses logic ) OWL ( Web Ontology Language )

 XML: uses tags to describe data  RDF: 1. provides a framework to describe resources. 2. uses triples written as XML tags to express this information as a graph.

Q: There is a father relation between Anakin and Luke ok but, who or what is Anakin and Luke ? What does father mean anyway? A: RDF uses uniform resource identifiers (URIs) to direct the computer to a document or object that represents the resource.

 Computers don't have the kind of vocabulary that people do. So the computer has to have documents that describe all the words and logic to make the necessary connections.  RDF-S: adds classes, subclasses and properties to resources, creating a basic language framework  OWL: formalizes ontology, describes relationships between classes and uses logic to make deductions. It can also construct new classes based on existing information.

. Explanation; The first URI is the subject. the subject is me. The second URI is the predicate. It is "reallyLikes." The third URI is the object. The object is Tim Berners-Lee's book "Weaving the Web." So the RDF statement above says that I really like "Weaving the Web.“ RDF code;

 To declare a vocabulary or properties  specify the (multiple)-inheritance links between the types of classes (subClassOf or subProperty);  machines determine the meanings of resources based on properties and classes.

man an adult male person has for mother to have for parent a female. We declare a class #Man, sub class of #Person and #Male, and a property #hasMother having sub property of #hasParent, and that is used between instances of the class #Human and instances of the class #Female.

making logical deductions. For instance, given the ontology above, a Semantic Web agent could infer that since "Goose" is a type of "DarkMeatFowl," and "DarkMeatFowl" is a subset of the class "Fowl," which is a subset of the class "EdibleThing," then "Goose" is an "EdibleThing."

A property is symmetric.

 Precise search results  Time efficient for human  Easy to publish information  More human like thinking ( one step closer )  Data integration  Machine process-able

 The learning curve. RDF was developed by people with academic background in logic and artificial intelligence. For traditional developers it is not very easy to understand.  All the web pages’ content must be changed which is a long process.  Unrealized idea; "This simple idea, however, remains largely unrealized."  Two formats for one piece of data: one for human viewing and one for machines  concerns regarding censorship and privacy (for governments to control the viewing and creation of online information )

 Semantic Web infrastructure - stimulate the network effect of data  Data Access  Best Practices for vocabulary / ontology development  Development of ontology registries for Open vocabularies