Re: RE: working definition of baseline

Thanks, John. A few comments on some of your comments, preceded 
by "LGR":

1. WCAG needs authors to use technologies for which accessible user 
agents are available to the users. We refer to such a set of 
technologies as a baseline (and we need a better word than baseline 
for such a set of technologies).

JS: I agree, but would like to unpack "accessible user agents" a bit. 
We
want authors to use technologies for which there are user agents that
(a) render content produced by those technologies in an accessible way
and (b) are accessible to users with disabilities. 

LGR: Yes, although we probably need to specify that they 
render "properly authored" content in an accessible way. 


3. A baseline can be defined for a given population of users at a 
given point in time, that is, it is possible to analyze the 
accessibility properties of user agents and to assess what user agents 
should be available to a set of users and come up with the list of 
technologies supported by accessible user agents. 

JS: That phrase "should be available" jumped out at me.Authors can't
assume that something "should" be available. They have to be able to
assume that the Something either is or is not available. The 
assumptions
may be constrained by government or corporate policy or in some other
way, or the author may be in a position to know for certain that a 
given
technology *is* available (e.g., when developing an intranet for a
specific client who has spelled out system requirements, etc.). If 
there
isn't a clear policy and there isn't certain knowledge, then the author
has to assume that only the most basic technologies are supported by 
and
active in the user agent.

LGR: Yes, as I was trying to write this, it is clear that this 
analysis becomes tricky. So the assertion that it is possible to do 
the analysis is an important one. If we really require that all user 
agents support the technology, I think we are back in the lowest-
common-denominator, html-only world. If there is a user agent that is 
available to the user that supports the technology in an accessible 
way, I think we should permit the author to use that technology, even 
if that isn't, for instance, a user's preferred user agent. On the 
other hand, we can't require that the user switch platforms because 
there is only an accessible user agent for the technology on some 
other platforms. The analysis probably includes assumptions about the 
platforms used by (or available to) the audience.

Received on Friday, 6 May 2005 20:19:48 UTC