Re: accessibility and usability

Barbara de Zoete wrote:

I am getting more and more confused as to the meaning of the words
'accessibility' and 'usability' *in the context of the world wide
web*. What do these two words mean? How do they differ from one
another? Where does the meaning overlap, if it does? Where do they
perhaps conflict with one another, if they do?

Usability = how well a user can make use of a site, e.g. how easy it is
to know what is a link, uncluttered interface, no blinking text, to
name just some issues.

Accessibility = how different browsers, people with disabilities,
people using text-to-speech browsers, or their hand phone, can make use
of the site. E.g. alt-text for images containing text, W3C
accessibility guidelines, valid HTML.

Often, the two terms are used interchangably. Usability is somewhat
more fuzzy. For example an internet agency may think "we don't have
money for accessibility", meaning they don't want to support WAP1 WML,
special print pages and so on. (Naturally they are misunderstanding web
technologies such as valid HTML and CSS which IMO make life *easier*
for the web developer.) But no internet agency I know would say "we
don't have money for usability"!

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