The advent of Web 2.0 technologies has allowed once static Web documents to be transformed into online interactive applications. To facilitate the accessibility of this dynamic content, Google have developed the AxsJAX framework that can insert Accessible Rich Internet Applications (ARIA) statements into the content dynamically. Such statements allow assistive technologies to interact with dynamic content and make it accessible to users. SADIe is an approach that uses semantic annotations of a Website's Cascading Style Sheet (CSS) to drive a transformation process that can improve access to Web pages for visually impaired users who use a screen reader. Previously SADIe transcoded static pages by refactoring the content into a format more suited to the sequential audio output of a screen reader. In this paper we present a prototype SADIe transcoder that uses CSS annotations to generate AxsJAX framework code and insert it into Web pages. Such an approach allows users to access static content using a consistent set of key presses in a manner akin to an online application. This demonstrates the flexibility of the SADIe approach as the same annotations can be used to generate an alternative transcoding format. It also supports the use of SADIe as a lightweight method for allowing Web designers to make use of AxsJAX without requiring knowledge of the underlying AxsJAX technologies.

1. Combining SADIe and AxsJAX To
Improve Accessibility
Darren Lunn, Simon Harper
and Sean Bechhofer

2. Summary
• SADIe transcodes content based upon the
meaning of the visual rendering.
• AxsJAX allows ARIA statements to be
injected into Web content dynamically.
• Can combine SADIe’s identification of
elements and AxsJAX functionality to
create consistent page interaction.
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3. The Web
• Focus on presenting information visually
– Images
– Columns
– Chunks
• Some knowledge is only available implicitly
from the page rendering.
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4. Implicit Information
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Banner
Menu
Main Content
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5. Assistive Technologies
• Traversal of content is serial.
• Important information may not be
encountered until later on.
• Some information such as menus can be
repeated for every page.
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6. Transcoding
• Adaptation of content from one format to
another.
• Rules / Patterns.
– Can adapt a large number of pages.
– Can suffer from reduced accuracy.
• Annotation.
– Accurate.
– Time consuming as every page is annotated.
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7. 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 the CSS
definition implicitly defines the purpose of
the Web element.
• A single CSS definition is applied to every
page within the Website.
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8. SADIe Transcoding
Heading
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Summary
Menu
Heading Summary
Main Story
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9. The Web 2.0
• Content can change dynamically without
page refreshes.
• Documents are no longer static but
interactive.
– YouTube
– Flickr
– Facebook
• Akin to an application.
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10. ARIA
• Accessible Rich Internet Applications.
• Allows developers to mark-up dynamic and
interactive regions of content
• Mark-up provides assistive technology with
access to dynamic content.
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11. Google AxsJAX
• Open source framework to insert ARIA into
documents dynamically.
• Collection of JavaScripts that contain all the
necessary code for inserting ARIA.
• Uses high level abstract patterns
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12. Content Navigation Rules
• A key part of the framework.
• Uses XML and XPath expressions to define
where ARIA should be inserted.
• Assigns key presses to ARIA statements to
allow users to interact with content.
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13. Using CSS To Define XPaths
• Xpath can use absolute locations.
– /html/body/table[3]/tbody/
• XPath can also use element properties to
match nodes.
– //ul[@class=‘X’]
• CSS employs element attributes to apply
rendering.
– <ul id=quot;cnnNavigationquot;>
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14. Use SADIe To Create CNR
• Use CSS annotations to identify areas of
content.
• Use annotations to generate the XPath and
AxsJAX Code.
• Rather than rearrange the document, inject
AxsJAX into document dynamically.
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15. Consistent Key Presses
• N: move to next chunk of information.
• P: move to previous chunk of information.
• M: jump to menu.
• S: provide a summary of the page
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16. SADIe + AxsJAX
Pressing S reads out the
summary but does not
loose the focus of the story
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17. Future Work
• More key presses
– Chose four key presses applicable to a majority
of pages
• User studies
– Demonstrated the technical feasibility of the
approach
• Dynamic content
– So far focused on consistent navigation of
static pages
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18. Summary
• SADIe transcodes content based upon the
meaning of the visual rendering.
• AxsJAX allows ARIA statements to be
injected into Web content dynamically.
• Can combine SADIe’s identification of
elements and AxsJAX functionality to
create consistent page interaction.
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19. Questions?
http://hcw.cs.manchester.ac.uk/