Nowadays most people are surfing in the Internet and enjoy the vivid websites, however, the visual disabilities use their own ways to get information on line. For example, the partial sight person has to use lens or adjust the size of fonts to help his reading. The blindness uses the reader, such as Adobe Reader, to ‘listen’ the websites. Some website designers go in for the beautiful design and ignore the demands of visual disabilities. As a result, the websites are enriched by flash; they cannot be adjusted and be read by reader software. The best website not only has abundant content but also can be accessed by different users.
The Feasibility of website design for visual disabilities
The disabilities are a large number of potential customers. In America,
Adults with disabilities are much more likely than adults without disabilities to report that the Internet has significantly improved the quality of their lives (48% vs. 27%). [Harris Interactive Survey 6/2002]
In this report, it shows not only a great deal of disabilities using the Internet, but also people who with disabilities found the Internet is more helpful, compared with who without disabilities. Therefore, form this report we can see a big market of disabilities customer in the Internet. Making our websites accessible to disabilities is getting more and more important.
WCAG and Section 508
In 1999, Web Accessibility Initiative (WAI) was founded by WC3. This organization’s purpose is to improve the accessibility of website for disabilities. It issued Web Content Accessibility (WCAG), which include fourteen rules: “
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 usage.
5. Create table 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. ” [Wendy Chisholm 1999]
In 1998, American government issued Section 508, which has 16 rules. However, 11 of them are from WCAG. Latter 5 rules aim at Section 508, such as supplying the accessories interface. The government regulated this 16 rules must be carried out in the governmental Internet and Internet web. In others countries also have such law or rules, for example the UK, Australia, Canada, France, Germany and Japan and so on.
The trouble might be met
Firstly a few web use color instead of prompt text. For instance, “Click green button to continue.” This could be trouble to the people who cannot identify color. Secondly, text is unreadable. Some webs maybe think about copyright or have not support a related interface. So as to the screen reader cannot recognize the text and read it for the people who cannot see. Thirdly, the size of font cannot be changed would disturb audiences who are low sight. Finally, although Flash MX has already changed, now it can support for accessibility, blind and low sight people might not know how to operate it. There are not enough introductions in the page that display flash. Besides, “Related items spaced too far apart” [Jakob Nielsen Oct 2002]. Sometime the feedback is out of the screen, but users could not know or the screen reader could not read for them and all of them could be a problem of intercommunion.
SolutionSolution 1: 2-D or N-dimensional method.
The important information is laid on the top of website, it is easy to get by sighted audiences. The reader software read down from left to right; the disabilities can catch the main ideas too. Adding one more dimension can help visual disabilities users to organize a whole picture in their mind.
“Blind users might also benefit more from a 3-D user interface than sighted users. I imagine a gestured interface, where users are surrounded by different types of information located at different spots.” [Jakob Nielsen, April 2003]
For example, a seaside website is added with a voice of man/woman describing the seashore. We also can add a background sound, such as the sound of sea or sea gull. In the future, feeling hardware will be realized. Then we can smell the sea and feel the sea breeze. The advanced website makes the audiences in a virtual surrounding. Not only the users with visual disabilities can access, but also the sighted people can feel actually.
However, I think this method has a disadvantage. If the user does not have audio equipment, all will become nonsense. So we turn to think about color solution.
Solution 2: color method.
This method suits for people who cannot identify colors. What should designers do are setting simple colors and matching colors reasonably. For instance, black text with white background is quite easy to see. IF you do want to match other colors, please make sure colorblind users can read them. Because colorblind people are not the same – all of them only consider red or green as gray. Some of colorblind people do not have the ability of identifying blue. Therefore, check the colors that you want to use by color design software.
Solution 3: readable text
Firstly, how does screen reader work? Screen reader use windows API to find out the correct characters which show on the website no matter they are displayed on the buttons or toolbars. Find the pronunciations in its dictionary. Then sent information to computer’s sound card. So if want to the text can be read, support an interface to windows API.
Solution 4: check accessibility.
Now we can check our web accessibility on line. Here is a free web that called Bobby Online Portal. Input the URL of your website, you will get a report about the level of accessibility. This website only can deal with one URL and do one demand every minute. But you can find other software which without limit on Bobby Online website.
ConclusionWebsites should do their best to meet the users’ requests. First of all, the designer need to make sure users can access in the web and get what they want. The most difficult thing is how the special audiences – visual disabilities use web. Considering blind audiences cannot see, the only way the can get information from the Internet is listening. So fitting the web design into the screen reader software is necessary. Make sure the software can read all the important information to the people who cannot see. This concern with the interface that connect web with software and make sure software can work with the web, such as flash interface. For the colorblind users, the best ways are setting the text color and background color in a high ratio. Moreover use safe-color which the colorblind people will not miss. The text can be easily identify will help people who have to use magnifier. Besides, the size of text can be changed to big. Therefore, display tool bar on the top of website. Different disabilities audiences can choose which style they like. After they make a choice, this web page will be refreshed, all of the pages in this web will in the same style until users change it. Follow WCAG and Section 508 and check the accessibility on line—Bobby Online website. Even if the above content may not consider all the problems the visual disabilities would meet, web designer could play a role like a visual disability and try to know t what they should do for the special users. Moreover, ask people who got problems with sight do the questionnaires. According the statistical results, designer also can find out what requests are and what difficulties they usually meet are.
[Henrik Thovtrup 1991] useit website http://www.useit.com/papers/standards.html 1991
[Humphrey Taylor 2000] Harris interaction website http://www.harrisinteractive.com/harris_poll/index.asp?PID=93
June 2000
[Ian Graham 2003] Ian Graham, Web Usability, Pearson Education Limited 2003, Great Britain, 2003
[Jakob Nielsen 2003] useit website http://www.useit.com/alertbox/20030407.html April 2003
[Jakob Nielsen 2002] useit website http://www.useit.com/alertbox/20021014.html October 2002
[Jakob Nielsen 2001] useit website http://www.useit.com/alertbox/20011111.html November 2001
[Jonathan Lazar 2004] Jonathan Lazar, Alfreda Dudley-Sponaugle and Kisha-Dawn
Greenidge, Improving web accessibility: a study of
Webmaster perceptions, Computers in Human Behavior,
Volume 20, Issue 2, March 2004, Pages 269-288
[Robert Hess 2000] Microsoft website
http://www.microsoft.com/China/msdn/Archives/msdnonline/features/articles/hess10092000.asp
October 2000
[Scott Mitchell 2004] Microsoft website
http://www.microsoft.com/china/msdn/library/webservices/asp.net/USdnasppacsaraf1.mspx
September 2004
[Shawn Henry 2004] W3C website http://www.w3.org/WAI/Policy/
July 2004
本文地址：http://com.8s8s.com/it/it34679.htm