B. Output Display Independence
C. Control Device Independence
Items we were unsure about and other notes
Priority 1
1. Provide alternative text
for all images, applets, and image maps, including images used as
submit buttons and all of the links within a client-side image map.
Otherwise, users who are blind, have low vision, or have chosen not to view graphics will not know the purpose of the visual components on the page. Example.
Priority 1
2. Provide descriptions
for graphics, scripts, or applets that provide important information.
Otherwise, important information presented graphically (charts, billboards, diagrams) will not be perceivable to people with blindness, some people with low vision, and users who have chosen not to view graphics, scripts, or applets or whose browser does not support scripts or applets.
Priority 1
3. Provide textual
equivalents of all audio information. If the audio is
associated with a visual presentation (movie or animation), synchronize
the textual equivalents with the visual presentation.
Otherwise, users who are deaf, or hard of hearing, or who have turned sound off cannot perceive the information presented through sounds such as speech, sound effects, and music.
Priority 1
4. Provide textual and
auditory descriptions of moving visual information (movies,
animations, etc.). If the visual presentation is associated with an
auditory presentation, synchronize the auditory descriptions with
the existing auditory presentation.
Otherwise, users who cannot see (or look at) the page will not be able to perceive information presented through action, body language, or other visual cues that are not available through the auditory information (dialogue, sound effects, etc.).
Priority 1
5. The source of a frame
should be an HTML file.
If other types of information, such as images, are used as the source of a frame there is no way to attach alternative information to the information. In the image example, there is no way to attach alt-text (.see A-1).
How to include information in a frame.
Priority 1
6. Ensure that moving,
blinking, or scrolling objects, particularly those that contain text, may
be paused or frozen.
Some people with cognitive limitations or visual disabilities are unable to read moving text quickly enough or at all. Movement can also cause such a distraction that the rest of the page becomes unreadable for people with cognitive disabilities. Screen readers are unable to read moving text.
Priority 2???
7. Avoid ASCII art
and non-letter characters within words.
Since characteres are used to create a visual image there is no way to attach alt-text as with other images (see A-1). Character spacing and non-letter characters cause problems for screen readers.
Priority 2???
8. Provide visual
notification of sounds that are played automatically.
If a user is accessing the page without sound, information presented through sounds played automatically will go unnoticed.
When the sound is played, display a visual equivalent.
OR Enable the document to be reformatted for the purpose of presentation in different media and different output devices.
Priority 2
1. Separate content and
structure from presentation.
When content is tied to presentation, such as color-coding list items to distinguish between them in some way, it is difficult to impossible to transform the information into a different modality. Example.
Priority 2
2. Use elements and
attributes appropriately.
When elements and attributes are used inappropriately, such as using structural elements for presentation purposes (e.g., H1 to create large, bold face text), user agents that allow users to navigate through the structure will be unable to do so properly. Reformatting the page for other media and devices can also be difficult.
Priority 1 (yet don't want this as the first
item in this section) ???
3. If, after best
efforts, any page is still not accessible, provide a link to an
alternative page that is accessible, has equivalent information, and is
updated as often as the inaccessible page.
Some pages will be unable to fail gracefully at this time either because the visual components are too complex, or because assistive technologies or user agents (browsers) are lacking a specific feature.
Known instances when a text-only page will be needed:
Priority 1
1. Ensure that pages
using newer technologies will fail gracefully.
With each release of HTML new features have been added. Older browsers ignore new features and some users configure their browser not to make use of new features. These users often see nothing more than a blank page or an unreadable page when new technologies do not fail gracefully.
Priority 1 and 2
2. Enable
keyboard operation of all page elements.
Someone who is using the page without sight, with voice input, or with a keyboard (or other input device other than a mouse) will have a difficult time navigating a page if keyboard shortcuts are not provided for objects on the page. Access to image maps is impossible for these users if alternatives are not provided.
Priority 1
Priority 2
Priority 3
3. Provide interim
solutions to facilitate operation via assistive technologies and older
browsers.
Older browsers are unable to "Tab" to edit boxes, text areas and lists of consecutive links, making it difficult to impossible for users to access them.
Priority 1
1. For complex
frames, describe the layout and purpose of frames and how multiple
frames and their elements relate to each other.
Users with blindness and low vision often access the screen with "tunnel vision" and are unable to get an overview understanding of the page. Complex intertwinings of frames may also be difficult for people with cognitive disabilities to use.
Priority 2
2. Provide titles for images
(used as links), frames, horizontal rules, acronyms, and
abbreviations.
Priority 2
3. Provide
abbreviations for lengthy row and column labels.
Without abbreviations, a user who is using an auditory browser to navigate a table may hear the lengthy labels each time a cell is entered. Abbreviations decrease reading time and repetition.
Abbreviations for header labels ("abbr" on TH)
Priority 2
4. Group controls,
selections, and labels into semantic units.
Groupings provide meta-information about relationships between controls that are useful for all users.
Priority 2
5. For complex
tables, provide summaries, associate cells with row and column
headers, and group cells into categories.
These guidelines benefit users that are accesing the table auditorally or viewing only a portion of the page at a time (users with blindness and low vision, or using an auto-pc, or devices with small displays)
Priority 2
1. Create link phrases
that make sense when read out of context, but that are not too verbose.
Users that access a page auditorally (users with blindness, low vision, or those using an auto-pc) often tab through the links on a page. If a link does not make sense when read out of context, they will have to stop to read around the link to gather the context.
Priority 2
2. Use elements and attributes that
comply with a W3C HTML, CSS, or XML specification.
By avoiding proprietary elements and complying with a W3C specification you increase the likelihood that your page will be more consistent across platforms as well as more usable by a variety of populations.
3. recommend against absolute font sizes and absolute positioning. Related as layout techniques...(from Charles McN)
4. Avoid color combinations that cause problems for people with color blindness in its various forms.