the sadie transcoding platform
DESCRIPTION
The World Wide Web (Web) is a visually complex, dynamic, multimedia system that can be inaccessible to people with visual impairments. SADIe addresses this problem by using Semantic Web technologies to explicate implicit visual structures through a combination of an upper and lower ontology. By identifying elements within the Web page, in addition to the role that those elements play, accurate transcoding can be applied to a diverse range of Websites.TRANSCRIPT
The SADIe Transcoding Platform
Darren Lunn, Sean Bechhofer and Simon HarperThe University of ManchesterSchool of Computer Science
The Web
• Designed with a focus on presenting information in a visual manner– Images– Columned Layout– Chunks
• Some knowledge is only available implicitly from how the page looks
• Can be difficult to access for users of screen readers
Implicit Knowledge
= Advertisement
= Banner
= Main Content
= Menu
Transcoding• The adaptation of Web content to suit the needs of the browsing device
• Heuristic Transcoding– Uses rules / patterns– Can adapt a large number of pages– Can suffer from reduced accuracy issues
• Semantic Transcoding– Uses annotations– Accurate adaptations– Time Consuming As Every Page Is Annotated
SADIe in Action
ImageAdvertisement
Tabs
BannerMain Menu
Banner
Headline Story Overview
Main StoryMain Story
Story Overview
Headline
SADIe Approach
• The visual rendering of a Web element informs the user of its purpose
• The CSS defines the visual rendering
• Identifying the purpose of a CSS definition implicitly identifies the purpose of the Web element
Exploiting CSS
cnnNavigation{
float:left;
border-width:0 1px 0 0;
border-style:solid;
. . .
}
CSS<ul class="cnnNavigation">
<li><a href="/">Home</a></li>
<li><a href="/WORLD/">World</a></li>
<li><a href="/US/">U.S.</a></li>
. . .
</ul>
(X)HTML
Annotation Through Ontology
. . .(X)HTML (X)HTML (X)HTML
. . .CSS CSS CSS
Upper Ontology
. . .Website Ontology
CNN (Partial) Ontology
Transcoding Architecture
SADIeProxy
Web Page
IdentifyOntology
QueryOntology
Transcode Web page
User
Basic User Interface
Advanced User Interface
Incorporated Into Website
Conclusions• SADIe combines the benefits of both Heuristic and Semantic Transcoding
• Annotation occurs at the CSS level using an ontology
• One annotation propagates to all pages within the Website
• Transcoding is achieved via a proxy
• SADIe can be instigated via a User interface or embedded within a page
Questions?
http://hcw.cs.manchester.ac.uk/research/sadie/
http://hcw-eprints.cs.manchester.ac.uk/23/
http://sadie.cs.manchester.ac.uk/