CIS 421 › Accessibility› Accessibility Problems
Accessibility Problems we need to address
Visual Disabilities:
Blindness
- Blind users use screen readers to read content to them
- Screen readers read text but they do not read other types of content (e.g., images, video, Flash animations, etc.).
- Screen readers read HTML page in a linear fashion, starting at the top, so the reader may have to listen to the least important information first. .
- Blind users use the keyboard (tab key) rather than the mouse to navigate, so that mouse events written in JavaScript do not work.
- Data tables can be very confusing when they are read
- Frames are difficult to understand
- Screen reader may not support image maps.
- Users expect links to take them somewhere. .
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low vision
- Require screen magnification
- Require higher contrast text from background
- need to be able to use own user stylesheets
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color blindness:
- may not understand elements that are color-coded
- may not be able to discern text from background
Hearing Disabilities:
Deafness:
- Audio is unusable in audio and video clips
- Providing sign language versions would not necessarily help
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Motor Disabilities
- cannot use mouse
- fine motor skills impaired
- loss of limbs
- Most assistive technologies are accessible through the keyboard or emulate the keyboard
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Cognitive Disabilities (also applies to those with low reading skills)
- user cannot comprehend a certain type of content (e.g., text, numbers, pictures)
- user reads one word at a time and cannot remember long sentences or make meaning out of them
- Individual has difficulty concentrating for more than a short amount of time, particularly if there are distractions such as animated GIFs
- user may have very low or no reading skills and gets information from pictures
- photoepileptic seizures are caused by strobe-like effects and flicker. images that flicker at the rate of 55 flickers per second may violate Section 508. Be especially careful with Flash.
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Resources
Readings and Links for Accessibility
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