Things Only I Can See
Students of physics cite Emmy Noether’s theorem as the key to understanding such principles as the conservation of energy. Noether’s work was critical to the development of what we now know as modern abstract algebra, which served to demystify the laws of physics for people a lot smarter than me. (I’m baffled by physics and beyond help).
Do we have the beginnings of a similar architecture for creating compliant, accessible web applications? There was a terrific article by Martin Kliehm about a week ago on A List Apart about the W3C’s standards draft for creating accessible Web 2.0 applications. (It’s known as ARIA for Accessible Rich Internet Applications). The intention is to increase usability by sidestepping some of the limitations of (X)HTML, tapping into the extensibility features inherent in compliant browser environments.
Kliehm presents a good overview of the new attributes, including semantic identifiers, schema namespaces and extending the document type definition (DTD). One of the more interesting developments is the ability to turn any item on the page into an object that can contain focus, thus enhancing tab navigable accessibility:
Assistive technologies need to know what object they are working with and which item has focus. Currently, only links and form elements can have focus. ARIA-State extends common text containing elements with the tabindex attribute, allowing these elements to receive focus either through scripting or via tab navigation.
For example, currently the only way to give focus to a flickr text input is by clicking on it with a mouse. With tabindex=”0″, it would become keyboard accessible. Moreover, the tabindex value can be negative. Elements with a negative tabindex can receive focus via scripting, but are excluded from tab order.
Ah, but Kliehm also aludes to a potential problem. No issue relating to web accessibility can be discussed without a mention of Joe Clark, who argued two years ago that negative tab indexing once proposed by IBM and Mozilla disregarded web standards. Clark felt that “harmonizing” on a flawed spec (propagated by Microsoft, of all people) contradicted the very standards that the W3C was attempting to put into place. In response, the role attribute was introduced as an XHTML 1.1 module; this and other property recommendations are expected to be fully endorsed by the W3C this year.
Accessibility or markup validation … can’t we have it both ways?