1. Resource Description Framework (RDF) developed by World Wide Web Consortium (W3C) by Satya

2. How do we find things in real world Library Video store Phonebook Each of these systems is based on metadata i.e. data about data. This data about data is called metadata What about the web Dumb, brute force method hardly any metadata

3. LibraryVideo store Telephone Directory metadata1 metadata2 metadata3 ???

4. Is the foundation for processing metadata. Enables automated processing of web resources. Provides a generic metadata architecture. Uses XML as its language. RDF

5. Applications of RDF In resource discovery. In cataloging. Digital Libraries. Intelligent Software Agents. Web of trust.

6. RDF model RDF model: Presents an abstract, conceptual view framework for defining metadata. It is based on the following concepts. Resources: These are the things being described by RDF expressions. e.g.www.umr.edu or a part of it e.g. www.umr.edu/~madrias.www.umr.edu/~madrias Property: Is a specific aspect, characteristic, attribute or relation used to describe a resource. Statement: A statement in RDF consists of resource + property + value subject predicate object

7. example For the statement “Sanjay Madria is the creator of the web page www.umr.edu/~madrias. www.umr.edu/~madrias We have RDF statement as And node and arc diagram as Subject(resource) www.umr.edu/~madrias Predicate(property)creator Object(literal) “Sanjay Madria” www.umr.edu/~madrias Sanjay Madria

8. RDF syntax RDF syntax is needed for the purpose of creating and exchanging the metadata. [1]RDF ::= [' '] description* [' '] [2]description ::= ' ' propertyElt* ' ‘ [3] idAboutAttr ::= idAttr | aboutAttr [4] aboutAttr ::= 'about="' URI-reference '"‘ [5] idAttr ::= 'ID="' IDsymbol '"‘ [6] propertyElt ::= ' ' value ' ‘ | ' ‘ [7] propName ::= [ NSprefix ':' ] name [8] value ::= description | string [9] resourceAttr ::= 'resource="' URI-reference '"' [10] URI-reference ::= string, interpreted per [URI]URI [11] IDsymbol ::= (any legal XML name symbol)XML name symbol [12] name ::= (any legal XML name symbol) [13] NSprefix ::= (any legal XML namespace prefix)XML namespace prefix [14] string ::= (any XML text, with " ", and "&" escaped)

9. Description: contains the statements about resource. idAboutAttr: indicates which resource is being described idAttr: gives the anchor-id of the resource aboutAttr:gives the URI of the resource being decribed. PropertyElt:contains the name of the property and the value of the property. PropertyName: Gives the name of the property using namesapaces. value:can be another resource or a literal. resourceAttr: Specifies some other resource that is the value of this property. IDsymbol, name:any legal name symbol. NSprefix:corresponds to XML namespaces String:corresponds to XML text.

10. Example: For the statement “Sanjay Madria is the creator of the resource www.umr.edu/~madrias We have the RDF syntax(using XML) as: www.umr.edu/madrias Sanjay Madria

11. RDF schema Provides the mechanism for declaring properties and also defining relationship between these properties and other resources S=rdfs:subclassOf t=rdf:type t s t t t t t t t t t t s t s s t t t t s t t rdfs: Literal rdfs:Class rdfs:ConstraintResource rdfs:ConstraintProperty rdfs:range rdfs:domain rdfs:ContainerMembershipProperty rdf:Property rdfs:Resource rdfs:type rdfs:subPropertyOf rdfs:subCLassof rdfs:seeAlso rdfs:isDefinedBy rdfs:comment rdfs:label

12. Example s t t t s t s s s s t s rdf:class xyz:Passenger Vehicle xyz:Truck xyz:Van xyz:Mini Van xyz:Motor Vehicle rdf:Resource

13. Advantages: Interoperability of metadata Machine understandable semantic discovery better precision in resource discovery. Uniform query capability for resource discovery

14. Conclusion Distributed Information on web. Metadata Introduction to RDF The various concepts of RDF.