2. Interesting Facts 8 to 9% of men and 0.05% of women suffer from color blindness 15 million blind and visually impaired in the U.S. 2.2 of every 1,000 people in the U.S. are deaf 3% of women and 2% of men will be diagnosed with carpal tunnel syndrome during their lifetimes
3. Disabilities that can Affect Web Accessibility Visual disabilities Blindness Low vision Color Blindness Hearing impairments Deafness Hard of hearing Physical Disabilities Motor disabilities
5. Visual Disabilities Be consistent with the layout, so if it is magnified context will not be lost Use high contrast images that can be used with style sheets Use alternative text with all images If video is used describe it in a text document Avoid non-standard document formats that may be difficult for a screen reader to interpret Avoid text presented as images
6. Hearing Impairments Include captions or transcripts of audio on the web Avoid over use of text and use images when necessary Remember sign language is a second language for hearing impaired
7. Physical Disabilities Avoid time limited response options on Web pages Always offer keyboard alternatives to mouse commands Use forms that can be tabbed through in a logical order
8. Accessibility Myths Accessible web is more expensive for streaming audio and requires higher bandwidth Accessible web requires two versions of the same website—text and graphical Accessible web is only required if you receive federal funding Web developers cannot be held liable if their client told them to ignore accessible design
9. References http://www.brailleinstitute.org http://research.gallaudet.edu/Demographics/deaf-US.php http://answers.yahoo.com/question/index?qid=1006011205418 http://www.afb.org/Section.asp?Documentid=3481 http://juicystudio.com/services/aertcolourcontrast.php#result http://www.velvetblues.com/web-development-blog/proper-use-of-alt-text-in-html/ Thatcher, Jim. Web Accessibility Web Standards and Regulatory Compliance. Berkley: Apress, 2006
Notas do Editor
WCAG Web Content Accessibility GuidelinesUAAG-User Agent Accessibility GuidelinesWAI—Web Accessibility Iniative
There are three approaches to making online content more accessible:Adaptive technology can allow for multimodal outputs or alternative inputs. For example, screen reader software can read the contents of a webpage to a blind person. But even though tech continues to get more sophisticated there are still problems, for example screen readers cannot compensate for images that don't have alternative text to describe it. Automated conversion can be done various ways. This month YouTube opened up its free software to automatically caption user videos. Solutions like this may address the challenge of making the extreme long tail of online content more accessible but they still present barriers. For example, I'm dubious that autocaptioning software will be able to compensate for poor audio levels, overlapping speech, slang, etc. Human development is probably the best way to make the content more accessible. That is, the content creators build the content in ways that extend its functionality and flexibility. For example, describing the meaning of an image is best done by its creator. From Blog
Proper Use of ALT TextBelow, we’ve listed a few cases you’ll encounter and how to use the ALT attribute.Meaningless or decorative image. Sometimes, you will have an image that is used as a spacer, a bullet, or is used for some creative effect. In this case, you’d simply specify a blank alt attribute, like this alt="". (For bullets, you may also use an asterisk, like this alt="*".)Image contains meaningful text. When your image contains text, you should put that text in the ALT attribute. Similarly, if you use an image as a link, the ALT attribute should contain the text in the image, or the link text that you would have used had you not chosen an image.Image contains meaningful non-textual information. Sometimes, an image may not fall into either of the above categories. This might be the case if it is a photograph or a graph, or some other type of informational image. In this case, the appropriate ALT text would be a brief description of the image. For a graph displaying Boston temperature data, for example, you might write alt="Boston has seen steady temperature increases during the past decade." If, however, you want to supply a simple description, you could use square brackets and use the alt attribute like this, alt="[Graph of Mean Temperature in Boston, MA during the 1990's]".In addition, there are two guidelines that should be followed. First, alt text should be kept to under 50 characters. And second, you should avoid using specialized symbols. If you need to include a symbol, consider a textual alternative.