"The power of the Web is in its universality. Access by everyone regardless
of disability is an essential aspect."
-- Tim Berners-Lee, W3C Director and inventor of the World Wide Web.
What is Web Accessibility and Web Usability?
Web Accessibility is a term used to identify the extent to which information on Web pages can be successfully accessed by persons with disabilities including the aging.
Web Usability is the term used to identify the extent to which information accessible on the Web is in a form that can be used efficiently and effectively.
A majority of Web pages are not designed and coded properly. Problems occur for the visually impaired when they depend on an adaptive device like a screen reader (software) to convert Web pages into sound using synthesized speech techniques. If graphics are not properly labeled with the ALT tag, the screen reader cannot interpret the information. Other problems can be addressed by the following:
A person who cannot hear may want to see the information.
A person who cannot see may want to hear the information.
A person who is not able to move quickly or easily may want to use as little movement as possible to see or hear the information.
A person who does not read well may want to hear the information and see words highlighted as they are read.
A person who uses an early browser or a slow Internet connection may want the information without all the extra decor.
Why is Web Accessibility Important?
There are more than 54 million physically disabled people who are unable to access information on the Web. Under the American With Disabilities Act, the Internet is viewed as a resource of "public accommodation" and must be accessible by all people.
A Solution - Design with usability in mind.
1. PRESENTATION. Design content and presentation separate in order to meet
user's needs and preferences.
a. CSS, Cascading Style Sheets are stored separately from the content to which they apply.
2. INTERACTION. Design content allowing user interaction.
3. COMPREHENSION. Design content that is easy to use and understand.
4. TECHNOLOGY CONSIDERATIONS. Design site for compatibility.
5. W3C standards. Design site using standard guidelines that will ensure legality with the American with Disabilities Act.
BOBBY can help Web page authors identify and repair Web accessibility problems. Also view CAST for additional tools. Here are a few tips:
contain "ALT" attribute.
Links should contain the "TABINDEX" attribute.
Presentation of content should be formatted in separated style sheets.
Site navigation mechanisms should be clearly distinguished from the main content to make them easy to locate.
Identify headers for the table rows and columns.
Provide a summary for tables.
Convey information in other ways besides color.
Use relative sizing and positioning (% values) rather than absolute (pixels).
Do not cause a page to redirect to a new URL.
Explicitly associate form controls and their labels with the LABEL element.
Avoid distracting motion.
Identify the language of the text.
If you can't make a page accessible, construct an alternate accessible version.
If Web content employs these design principles, then users should be able to access the content using adaptive strategies and assistive technologies. A screen reader is an example of an assistive technology that reads the page aloud.