Blindness
|
Challenges |
Solutions |
| Images, photos, graphics
are unusable. |
Provide text descriptions,
in "alt" tags and, if necessary, longer explanations
(either on the same page or with a link to another page). |
| Users often listen to
the Web pages using a screen reader. |
Allow for users to skip
over navigational menus, long lists of items, ASCII art, and
other things that might be difficult or tedious to listen to. |
| Users often jump from
link to link using the TAB key. |
Make sure that links
make sense out of context ("click here" is problematic). |
| Users generally do not
use a mouse. |
Don't write scripts
that require mouse usage. Supply keyboard alternatives. |
| Not all screen readers
support image maps. |
Supply redundant text
links for hot spots in image maps |
| It may be difficult
for users to tell where they are when listening to table cell
contents |
Provide column and row
headers (<th>). Make sure that tables--especially those
with merged cells--make sense when read row by row from left
to right. |
| Complex tables and graphs
that are usually interpreted visually are unusable. |
Provide summaries and/or
text descriptions. |
| Frames cannot be "seen"
all at once. They must be visited separately, which can lead
to disorientation. |
Don't use frames unless
you have to. If you use them, provide frame titles that communicate
their purpose (e.g. "navigational frame", "main
content"). |
| Colors are unusable. |
Do not rely on color
alone to convey meaning. |
| Users expect links to
take them somewhere. |
Don't write scripts
in links that don't have true destinations associated with them
(e.g. href="javascript: function(this)"). |
Motor Impairments
|
Challenges |
Solutions |
| Users may not be able
to use the mouse. |
Make sure that all functions
are available from the keyboard (try tabbing from link to link). |
| Users may become fatigued
when using "puff-and-sip" or similar adaptive technologies. |
Provide a method for
skipping over long lists of links or other lengthy content. |
| Users may be using voice
activated software. |
Voice-activated software
generally cannot replicate mouse movement, so make sure that
all functions are available from the keyboard. |
| Users may not be able
to control the mouse or the keyboard well. |
Voice-activated software
generally cannot replicate mouse movement, so make sure that
all functions are available from the keyboard. |
| Users may not be able
to control the mouse or the keyboard well. |
Make sure that your
pages are error-tolerant (e.g. ask "are you sure you want
to delete this file?"), do not create small links or moving
links. |