The document discusses evaluating the accessibility of rich internet applications. It presents QualWeb 3.0, which introduces new modules to trigger and observe changes to the DOM tree caused by JavaScript. An experiment evaluated 50 inspiring web applications and found it could automatically trigger changes without human intervention. The results showed accessibility evaluations varied between states and more fails/warnings were found compared to static evaluations. The approach allows more complete evaluation of rich internet applications against WCAG 2.0 techniques.

1. Evaluating the accessibility of
Rich Internet Applications
Nádia Fernandes, Daniel
Costa, Sérgio Neves, Carlos
Duarte, Luís Carriço
W4A 2012 – Accessible Web 2.0

2. Motivation
• The Internet has become an indispensable
tool for our everyday life
• And it is used by all kind of people
– With different physical and/or mental capabilities
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3. Problems
• The content of Web pages must become
accessible to all users
• Developers need a way to help them
implement an accessible page
• Tools should be provided to enable evaluation
of the accessibility
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4. Solution
• The Web Content Accessibility Guidelines
(WCAG)
– A set of best practices for developing an accessible
Web page
• Automated accessibility evaluators
– QualWeb (Nádia et al)
– Achecker
– And more…
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5. New Challenges
• Web pages are no longer static content displayers
• With the Web development, Rich Internet
Applications are becoming a trend
• New elements are introduced on the Dom tree
triggered by javascript functions
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6. New approach
• QualWeb 3.0
– New WCAG techniques evaluated (including CSS
techniques)
– Added a new module that triggers and observes
changes made on the Dom tree
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7. Architecture
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8. Interaction Simulator
• This component is responsible for activating
interactive elements in the HTML document
– For each interactive element it is attached a
function (Crawler) that triggers this element
periodically
– At the same time there is an Observer which
analyses the Dom tree to see if it has changed
– A change in the Dom tree is considered a new state
of the RIA
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9. QualWeb evaluator
• The evaluator receives the new state and
performs the evaluation
• 20 HTML WCAG 2.0 and 6 CSS WCAG 2.0
• Then generates an EARL report
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10. Experimental study
• 5o inspiring Web applications
– http://speckyboy.com/2009/09/02/50-inspiring-
web-application-and-service-web-site-designs/
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11. Goal
• The goal of this experiment is to validate this
new approach
• Understand if it is possible to automatically
trigger changes on the Web page
• Understand if those changes affect the
accessibility of the page
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12. Results
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13. Results
• There was an average of 5 different states per
page
– The number of fails and warnings increased 4% and
10% in comparison with the original state
• In this experiment the average of pass results is
28% , fail results represent an average of 12% and
60% for warnings.
• 43% of the Warning results come from the CSS
evaluation
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14. Advantages
• The main advantages are:
– The evaluation is made on browser environment
• VS “Offline” evaluation
– Evaluates WCAG 2.0 techniques (HTML and CSS)
• VS WCAG 1.0
– Can evaluate parts of the Web page that were
otherwise unreachable
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15. Conclusions
• The results obtained show that it is possible to
evaluate automatically states that can be
triggered without human intervention
• We demonstrated that there are differences when
evaluating different states of the Web page
• We have developed a more complete evaluation
of Web pages
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16. Future Work
• Implement more WCAG 2.0 techniques
• Perform more tests
• Remove some limitations we had
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17. Questions?
• Daniel Costa – dancosta@di.fc.ul.pt
• Nádia Fernandes – nadiaf@di.fc.ul.pt
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