Re: Technology-specific checks: XML, HTML, SMIL, CSS

My comments, submitted ex officio, are as follows:

1. Wendy's draft is encouraging in that it tends to confirm the viability
of the approach agreed upon at last week's meeting. My few substantive
remarks are consequently directed more at the detail than at the principle
of the work.

2. Wendy is correct in noting that there are certain technical
specifications which are closely interconnected, for example HTML
(including XHTML) and CSS. These could be treated in combination rather
than individually. Thus, techniques could be provided for HTML/CSS, rather
than separately for HTML and CSS, where applicable. Similarly, techniques
corresponding to the scenario in which XML is used with a style language
(whether XSL or CSS) could be developed. More generally, one can
distinguish between markup languages intended to represent documents, and
style languages, which play a supporting, complementary role but generally
do not encode the actual content (text, auditory/visual data, etc.). Of
course, XSL formatting objects do include the contents of the document, in
rendered form; but this occurs at a later stage of processing than that at
which access-related style dependencies (visual/auditory/tactile
formatting according to users' and/or authors' preferences) need to be
taken into account. Thus, by the time the XSL formatting objects are
constructed, it is to be expected that the necessary application of style
rules will have been carried out in such a way as to satisfy the user's
needs; if this is not so, then an access problem would result, which needs
to be avoided. Stated differently, it is possible to describe a processing
model by which style rules operate on high-level semantic constructs in a
markup language to generate formatted output (including form controls and
other user interface components as required) which can then be presented
to the user. The guidelines should encourage such processing.

3. It is also true that some guidelines will be applicable only to a
specific subset of the available web-related technologies. This should not
give rise to any difficulties, provided that it is made clear to readers
of the guidelines that not every requirement is applicable to all
technologies, and further that the generality of the principles enunciated
in the document must be qualified by contextual factors operating within
particular domains. By working through the implications of the guidelines
in each technical area, the working group can provide an excellent basis
on which to apply the general principles to technologies that may be
developed in the future. Ths effort should also assist in the
distillationof basic tenets of accessible design, which can be expressed
and elaborated in the guidelines.

Received on Thursday, 1 June 2000 04:58:23 UTC