Re: When is a web site accessible?

On Wed, 13 Jan 1999, Charles McCathieNevile wrote:

  This is a personal answer to a question which, in my mind, involves some
  very difficult questions. It attempts to provide an answer which can be
  used in most practical situations, and explain something about what the
  answer means, and why it may not be perfect. (Full disclaimer on request...)
  
  First, the question is insuffficiently defined. I am going to interpret
  'accessible' as meaning the information is accessible to adults and/or
  reasonably developed children, without much reference to the capacity of
  those people to internalise and understand the information presented.
  
  (If you think my definition is nitpicking, you are right. If you think it
  is wrong in its assumptions, please explain why in a follow-up. If you
  think my answer is wrong, please do likewise. I would like to know...)
  
  My basic answer:

  A website which does the things that are specified in the Page Author
  Guidelines is very likely to be accessible. A website which does
  something that is counter to a priority 1 checkpoint of those guidelines
  is extremely likely not to be accessible. But there's a catch (or two):
  
  The explanation bit:
  By "very likely" I mean that it is possible to create a website that meets
  the guidelines but is not accessible. Somebody who thinks in terms of laws
  (a philosopher, lawyer, physicist, hacker) has a basic technical 
  background, and wants to create an inaccessible website which met all the
  requirements of the Page Author Guidelines could probably do so. But a
  person who was trying to do the 'right thing' and followed the guidelines
  with a modicum of care is unlikely to accidentally get it very wrong. It
  is true that in order to fit some of the wish-lists of people
  commissioning (or promising) websites, it may take a very thoughtful and
  skilled designer. But it takes a thoughtful and skilled person to make a
  skyscraper too. We just take it for granted, because we don't let anyone
  do it if we don't think they are good enough.
  
  By "extremely likely" I mean that I cannot think of a way it can be done -
  the guidelines are based on avoiding a number of blocks to accessibility,
  and if you create such a block then it is hard to do it in an accessible
  way. I suspect that it is still possible, but I leave it as an
  intellectual exercise.

  The big catch:
  The guidelines also need to be interpreted, some to a greater degree
  than others. One could say truthfully 'In order to create an accessible
  site, all that is required is that all the information and functionality
  of the site can be accessed in a completely device independent way, with a
  structure that is intuitively clear and comprehensible.'
  
  Unfortunately there are not a lot of people out there who can make use of
  such a statement. There are a (dwindling it seems) number of people to
  whom it is news. The guidelines elaborate on the statement itself, and add
  rationales and some specific checkpoints which are important in practise.
  They even attempt to define how important some of these things are. The
  techniques document outlines many ways of doing these things in the real
  world.
  
  This means that the guidelines are a compromise between perfect (but
  almost unusable) truth, and between complete (and therefore too big to be
  useable) specification of every detail, in a structure which provides
  several levels of detail (from the very coarse-grained approach summed up
  in the three section titles, to the very fine-grained approach of
  implementing each technique (or a functional equivalent if applicable)
  relevant to every part of a document).

Fortunately I think that they are a pretty good compromise.


(there was more. If you really want to know, email me)  

--Charles McCathieNevile -  mailto:charles@w3.org
phone: * +1 (617) 258 0992 *  http://purl.oclc.org/net/charles
W3C Web Accessibility Initiative -  http://www.w3.org/WAI
545 Technology sq., Cambridge MA, USA

Received on Wednesday, 13 January 1999 22:19:19 UTC