- From: Gerard Torenvliet <g_torenvliet@sympatico.ca>
- Date: Wed, 2 Apr 2003 09:49:20 -0500
- To: "'Graham Oliver'" <goliver@accease.com>, "WAI Mailing List" <w3c-wai-ig@w3.org>
I mostly agree with what Graham says here. However, since people continue to view 'accessibility' as meaning 'accessible to screen readers' and nothing else, we need to become a little more nuanced in our terminology. The idea that I've been working on lately is that both accessibility and usability are relational terms. That is to say, a design is not accessible (or usable) in and of itself, but only with respect to some target user or groups of users. In other words, accessibility or usability are dependent on the person or group of persons against whom those terms are being evaluated. Under this conception, usability and accessibility are actually orthogonal (but complementary). Accessibility is a measure of how much of the data and functionality presented by an interface that a user with certain characteristics can access. Usability, on the other hand, is a measure of the ease with which that data and functionality can be accessed by the same user. Note that there are a few implications of this approach: 1. A system can be designed that is highly usable to a target group of users. However, if that target group only includes those with a certain disability, it may not be very usable at all for those who do not have that disability. 2. A system can be designed that is highly accessible to users with a broad set of disabilities, but that is not usable for that group. For example, any corporation can take their web site and ensure that it complies with the letter of Section 508. Because this is the case, with enough work, all of the information and functions should be accessible. However, this does not mean that they will be easy to use; in fact, to the contrary - experience has shown that to make a web site that is accessible and easy to use cannot easily be achieved by retrofitting an existing inaccessible site. 3. Accessibility is a limiting criterion on usability. If data and information can't be accessed, it can't be used. When I get sufficient encouragement, I would like to flesh these ideas out to an article-length. Anybody on this list who wants to encourage me with a venue to publish would be welcomed! :-) Cheers, -Gerard -----Original Message----- From: w3c-wai-ig-request@w3.org [mailto:w3c-wai-ig-request@w3.org] On Behalf Of Graham Oliver Sent: April 1, 2003 7:13 PM To: 'w3c-wai-ig@w3.org' http://www.accease.com/tips/0304.html Cheers Graham AccEase Ltd : Making on-line information accessible Mobile : +64 21 458 967 Email : goliver@accease.com Web : www.accease.com
Received on Wednesday, 2 April 2003 09:49:23 UTC