The Universally Usable Web:Accessibility without Compromise

Harry HochheiserDepartment of Computer and Information Sciences

Towson Universityhhochheiser@towson.edu

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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)

1. Provide equivalent alternatives to auditory and visual content.2. Don't rely on color alone.3. Use markup and style sheets and do so properly.4. Clarify natural language usage5. Create tables that transform gracefully.6. Ensure that pages featuring new technologies transform

gracefully.7. Ensure user control of time-sensitive content changes.8. Ensure direct accessibility of embedded user interfaces.9. Design for device-independence.10. Use interim solutions.11. Use W3C technologies and guidelines.12. Provide context and orientation information.13. Provide clear navigation mechanisms.14. 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

• Operable – 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

• Understandable– Make text content readable and understandable– Make Web pages appear and operate in predictable ways– Help users avoid and correct mistakes

• Robust– Maximize compatibility with current and future user agents, including assistive

technologies

• 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– 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