W4A Transcoding Challenge

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/