- From: Jason White <jasonw@ariel.ucs.unimelb.edu.au>
- Date: Sat, 27 Oct 2001 16:51:24 +1000
- To: Web Content Guidelines <w3c-wai-gl@w3.org>
Upon analysis, I think OTACS 2 and the WCAG 1.0 priority 1 definition are, in effect, very similar, but OTACS 2 is less restrictive. In WCAG 1.0, priority 1 checkpoints were those which removed barriers that would otherwise make it absolutely impossible for an identifiable group of users to access the content. In applying this definition, the current state of technology (not actual implementations, but rather what was possible in principle using known algorithms and approaches) was taken into account. Thus, if certain functionality required to make the content accessible could be supplied by software, the corresponding checkpoint did not count as priority 1. Furthermore, the notion of what it meant for a user to "access the content" was somewhat narrow. It was assumed for example that loss of structure did not render the content completely inaccessible, but merely difficult to use. OTACS 2 is similar to the WCAG 1.0 priority 1 definition, but it involves a less restrictive concept of accessibility. It assumes that the user must be provided with means of reading, navigating and interacting with the content effectively. The checkpoints in the minimum set are those which, if satisfied, eliminate barriers that would otherwise prevent an identifiable group of users, with the aid of client-side software, from reading, understanding, navigating and interacting with the content. This formulation is equivalent to OTACS 2, but it is written from the user's rather than from the author's perspective. Essentially, the user's ability to read the content, traverse and appreciate its structure, or provide input via a user interface, will necessarily be restricted in ways that can't be rectified by client-side software unless the checkpoints in the minimum set have been met. Thus I think OTACS 2 and the foregoing equivalent are broader than WCAG 1.0 priority 1, in that they do not take the restrictive approach to accessibility which the latter implies. I can't think of a good, short label that can be attached to my alternative formulation, unfortunately. Perhaps it should be called the FILU principle: "functionality is lost unless", where "functionality" means the user's ability to perceive, understand and interact.
Received on Saturday, 27 October 2001 02:51:31 UTC