RDFa PrimerBridging the Human and Data webs

Presented by: Didit (2008-22485)

RDFa introduction

RDFa, Resource Description Framework in attribute

Is a set of extension to XHTML now part of W3C recommendation Have a purpose

to augment web page visual data with machine readable hints

to reduce the gap between what user and programs understand from a web page

RDFa background

In a traditional technology (ordinary html page) there are a large gap between what human and programs understand

RDFa technology

RDFa used a generalize attributes from XHTML meta and link elements

This allow user to annotate XHTML markup with semantic

RDFa technology

Set of attribute provide by RDFa about: a URI specifying the resource of the

metadata rel & rev: specifying a relationship with another

resource href, src, resource: specifying the partner

resource property: specifying a property for the content of

an element

RDFa technology

Content: optional attribute that override the content of the elements when using the property attribute

Datatype: optional attribute that specifies the datatype of text specified

Typeof: optional attribute that specifies the RDF type of subject

RDFa example

Consider Alice a bloger who wants to declare her content to be freely reusable as long as she receive due credit when her article are cited

RDFa example

Labeling the title and author Use property and attribute Import existing DC vocabulary to express title and

author

RDFa example

Expressing multiple items per page

RDFa example

Nesting cause overriding of the outer value

RDFa example

Describing contact information

RDFa example

Describing social networks

Benefit of RDFa

Publisher independence Data reuse Self containments Schema modularity Evolvability