Transcript ppt

RDFa Primer
Bridging the Human and Data webs
Presented by: Didit (2008-22485)
RDFa introduction
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RDFa, Resource Description Framework in
attribute
Is a set of extension to XHTML
now part of W3C recommendation
Have a purpose
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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
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In a traditional technology (ordinary html
page) there are a large gap between what
human and programs understand
RDFa technology
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RDFa used a generalize attributes from
XHTML meta and link elements
This allow user to annotate XHTML markup
with semantic
RDFa technology
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Set of attribute provide by RDFa
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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
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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
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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
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Labeling the title and author
 Use property and attribute
 Import existing DC vocabulary to express title and
author
RDFa example
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Expressing multiple items per page
RDFa example
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Nesting cause overriding of the outer value
RDFa example
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Describing contact information
RDFa example
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Describing social networks
Benefit of RDFa
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Publisher independence
Data reuse
Self containments
Schema modularity
Evolvability