Accessibility VS. Usability

[HTMLBasicTutor]

Further to Doc's reference of accessibility becoming manditory:

WEB SITE ACCESSIBILITY
Web sites which are perfectly accessible to fully-abled people may be impossible for people with disabilities to access. For example, that beautiful new law firm site that your high-priced designer just created may be impossible for a person using screen reading technology to navigate; particularly if they are blind/low vision or have a specific learning disability. Those “frames” or neat drop-down Java menus on your site may be impossible to use via voice command software. Your fancy “streaming audio” online CLE courses or video conferencing events may be impossible for a deaf person to hear. And so on.

But ADA compliance shouldn’t be the only reason to make your site fully accessible. The experts tend to agree that universal design is good for everyone. According to Kelly Pierce, the co-founder of “Digit-Eyes,” the Chicago blind computer users network, and who serves on the Techwatch committee for the National Council on Disability, “when World Wide Web sites are accessible to people with disabilities, they are highly usable and accessible to everyone else as well.”

He continues: “As the Web matures and grows in popularity, webmasters can be less and less certain that the visitor is using the latest version of Navigator or Explorer.” In other words, accessible Web design also assures “backwards compatibility” with older Internet browser software. But it’s not just older technology that benefits from good design. Many newer ways to access the internet benefit greatly from universal design, “people may be online with their PalmPilot, or on WebTV, or browsing using their telephone. The closer companies and other organizations design their sites to HTML standards, the more accessible they are to people with disabilities and everyone else,” says Pierce.

According to David Clark, webmaster for the Center for Applied Special Technology (http://www.cast.org/), “it is not just accessibility for people with disabilities, it's about ‘universal design.' Making the changes required for people with disabilities benefits everyone. Examples include people with slow modems who turn graphics off, people who access the Web while driving in a car, and even doctors wanting to access the Web while their hands are busy with a surgery.”

In the future, therefore, universal access will mean that internet kiosks, electronic textbooks and other new information appliances will be accessible to everyone. But how do you make your site universally accessible? It’s not that hard. It just requires some common sense. (And if you do it right, it should not require the maintenance of a separate “text-only” Web site).

Is Your Site ADA-Compliant ...
or a Lawsuit-in-Waiting? This article is from the November 1998 issue of The Internet Lawyer newsletter

Have you ever heard of the Sydney Olymics and Target getting sued due to the inaccessibility of their sites?

Web accessibility lawsuits- some past cases

[Webnauts]

On my web sites I use Javascript to open external links and I suppose are accessible. If you have Javascript disabled in your browser you still will access the destination page. I ned to ass here that you are already warned through the link title attribute and the alt tag of the new window symbol next to the link, indicating that a new window will open.

Do you see any accessibility problems there? For example look at the links in the "Resources" of the article.

Also I wrote many years back an article about this topic: http://www.webnauts.net/new-window.html (Am I probably contradicting)? I can explain.

[skodicious]

I heartily agree that accessibility is an important issue, especially for marketers. Accessibility, in a marketing sense, deals with increasing the audience size within any given market.

Usability makes elements of web or interface design more accessible and intuitive--thus increasing product usage or return visits.

[LazyJim]

The difference between accessibility and usability is that an inaccessible website blocks access to certain people by requiring a certain technology (e.g. mouse, Flash), or ability (e.g. sight, detailed mouse control); Whereas a web site with bad usability just takes more effort, skill or knowledge for some or all visitors to complete the task they came to do. Resulting in a portion of visitors not bothering and going away unfulfilled, or trying but giving up and getting annoyed.

Example
Imagine an article with a lot of text and images used to communicate the information.
If there is no text alternative to the images a visitor without the ability to see the images cannot access the information.
If the text is not presented well, even a visitor proficient at reading by sight can struggle to read the article. They may simply leave the site and/or can incur eye strain where usability is particularly bad.

The useit.com site contains further details, but ironically is not a great example of usability! (as already mentioned)

[HTMLBasicTutor]

Here is John Eric Brandt of jebswebs thoughts on Accessibility: Why should my website be accessible?

[HTMLBasicTutor]

When you find a huge population of Internet users, you definitely want to target them and make them want to visit your site. And one of the major groups that many web developers are aiming to target is that of the aging population.

More and more senior citizens are using the Internet at a regular basis. And no matter what your niche is, you can be sure that there will always be older people who would find your site and would want to read what you have in store.

This is more than enough reason to make your site more usable and accessible to the aging population....

4 Easy Steps to Make Your Site More Usable to Older People

[PerfectMoney]

for me accessibility related to speed,design and keywords placement,usability is about content,what user get once they reach certain page on your web