Introduction
Content adaptation in the ubiquitous Web:
- Content adaptation is an important element of the
Ubiquitous Web
- Focus on information resources, emphasis on multimedia
information
- In the ubiquitous Web information should be usable in different
contexts
- Existing resources have to be adapted to the actual
context
- Web infrastructure should provide several components
to enable efficient adaptation
Outline
Components for content adaptation:
- Context description
- Transformation for adaptation
- Negotiation protocols
- A distributed architecture
Context Description
Context must be described in a machine-readable manner
- CC/PP and UAProf
are available -- description of device capabilities and user
preferences
- DCI is in
progress -- interfaces to access dynamic properties (device capabilities,
configurations, user preferences, environmental conditions)
- MWI is working on device description
Adaptation
Some technologies are available for adapting contents
- CSS (format, style), ACSS (change of modality)
- Alternate content
switch
element in SVG, SMIL
- DISelect -- content
filtering and selection
- Transformations
Transformation
In multimedia documents both structure and media objects may have to be
transformed
- XSLT for structure transformation
- specific tools for media objects
Some problems with XSLT
- Validation: how to make sure that transformed
documents are valid?
- Streamed data: transforming data on the fly, large
documents
Negotiation Protocols
How to choose the right transformation(s) based on context description?
- compromise: available transformations and constraints from the
context
- negotiation to find the best compromise
HTTP 1.1 offers limited negotiation (choosing among the available
versions)
More flexibility is needed to adapt documents dynamically
Architecture
Several components are required:
- Context description
- Negotiation based on context
- Transformation of content and structure
Include these components in all clients and servers?
A Distributed Architecture
![NAC architecture](NAC.png)
Summary
Content adaptation is a key issue for the ubiquitous Web
It requires
- Context description:
on-going effort at W3C
- Transformation:
further research is needed
- Negotiation protocols:
lack of standardization effort
Thank you!