Transcript Accessibility without Compromise

The Universally Usable Web:
Accessibility without Compromise
Harry Hochheiser
Department of Computer and Information Sciences
Towson University
[email protected]
Universal Usability
• Interfaces that work for all users despite
differences in abilities, experience, or technology
• Not “dumbing down” the interface
• Not “Click here for text-only site”
• Not prohibitively difficult or expensive
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A four-step program for making your
site universally usable
• Learn
– Guidelines and Principles
• Test
– Use automated tools to identify usability problems
• Revise
– Fix major problems where possible
• Plan
– Build Accessibility into your next major upgrade.
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Learn: Accessibility Guidelines
• W3C Web Accessibility Initiative
– http://www.w3.org/WAI
• Web Content Accessibility Guidelines 1.0 (WCAG)
– WCAG 2.0 coming soon
• Section 508
• Ensure Graceful Transformation
• Make Content Understandable and Navigable
• What’s good for accessibility is good for all users
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Web Content Accessibility Guidelines (1.0)
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Provide equivalent alternatives to auditory and visual content.
Don't rely on color alone.
Use markup and style sheets and do so properly.
Clarify natural language usage
Create tables that transform gracefully.
Ensure that pages featuring new technologies transform gracefully.
Ensure user control of time-sensitive content changes.
Ensure direct accessibility of embedded user interfaces.
Design for device-independence.
Use interim solutions.
Use W3C technologies and guidelines.
Provide context and orientation information.
Provide clear navigation mechanisms.
Ensure that documents are clear and simple.
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Web Content Accessibility Guidelines (2.0)
• Perceivable
– Provide text alternatives for any non-text content so that it can be changed into
other forms people need, such as large print, Braille, speech, symbols or simpler
language
– Provide synchronized alternatives for synchronized media
– Create content that can be presented in different ways (for example simpler
layout ) without losing information or structure
– Make it easier for users to see and hear content including separating foreground
from background
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Operable
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Make all functionality available from a keyboard
Provide users with disabilities enough time to read and use content
Do not design content in a way that is known to cause seizures
Provide ways to help users with disabilities navigate, find content and determine
where they are
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Web Content Accessibility Guidelines (2.0),
continued
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Understandable
– Make text content readable and understandable
– Make Web pages appear and operate in predictable ways
– Help users avoid and correct mistakes
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Robust
– Maximize compatibility with current and future user agents, including assistive
technologies
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May become a “candidate recommendation” by April or May 2008
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Test
• Automated checks for compliance with guidelines
– Firefox Accessibility Extension (Illinois Center for Information
Accessibility) - functional accessibility evaluator?
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More tests – IBM aDesigner
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Still More Tests
• Multiple evaluations
– Different tests find different problems
• Screen Reader Output – Fangs for Firefox
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Revise
• Fix major problems and those that are easy
– Alt tags for images
– Language
– Inaccessible scripts
• Priority 1,2, then 3
– WCAG 2.0: A, AA, and AAA
• Nothing is ever perfect
• Note problems/shortcomings for redesign
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Plan
• Inventory accessibility concerns before the next
redesign
• Pay attention to
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Tables in layout
CSS usage
JavaScript/AJAX
Embedded content (Flash, Java, etc.)
• Develop plan for fixing problems in new design
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Universal Usability
• AJAX, JavaScript, and other flashy tools are
neat…
• But what do they really add to the user
experience?
• Use sparingly and appropriately.
• Resulting site will be
– More accessible
– Easier to test, maintain, and implement
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