Making sure that a solution is usable for a wide variety of people, with different abilities, understandings, and capabilities, ensures that the solution can be used as much as possible. This isn’t just a matter of developing for dif­ferent physical and mental abilities (though that’s important, especially from a social justice perspective). Accessibility also refers to the different modes we all operate under at differ­ent times. For example, sometimes we search, sometimes we browse. Sometimes, we’re lightning-focused, and other times we prefer to meander. There are contexts where a visual interface is more easily used, and other times when a verbal, auditory, or even textural inter­face might be more appropriate.

Designing for accessibility requires us to explore a full range of uses and modes in order to develop solutions that address the widest array of peo­ple possible.

Using the example of a map again, a long list of directions might be best rendered on a map instead of a text list since there are few visual cues in the list to help drivers know where and when to turn. A page of text, in either a list or story, doesn’t make it as easy to pick out the street names, map directions, and so on, as in a graphic map. However, given driving require­ments, a geographically-appropriate voice system might be even better than a map since the instructions can be spoken clearly precisely when they are needed, allowing drivers to keep their eyes on the road and not on a map or list. Of course, the most effective systems combine several types of renderings to increase their ac­cessibility and usability further.

Designing for accessibility requires us to ex­plore a full range of uses and modes in order to develop solutions that address the widest array of people possible. This awareness not only makes our solutions usable for a wider range of people, but it also makes them more useful across a wider range of contexts.

A selection of accessibility issues includes the following areas:

• Hearing impairment

• Speech impairment

• Vision impairment

• Dexterity impairment

• Color blindness (several types)

• Loss of balance or mobility due to age or illness

• Searching contexts versus browsing contexts

• Entertainment versus information contexts