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Re: [w3c-wai-gl] <none> - Bobby

From: Charles McCathieNevile <charles@w3.org>
Date: Thu, 25 Feb 1999 16:57:09 -0500 (EST)
To: Peter Munro <disabled@tdbank.com>
cc: w3c-wai-gl@w3.org
Message-ID: <Pine.LNX.4.04.9902251646300.21555-100000@tux.w3.org>
Bobby is a marvellous tool, being developed by CAST, to highlight
accessibility problems in web pages.

However, since the bobby team is using the W3C's Web Content Guidelines as
their reference, there is a major problem if those guidelines use Bobby as
their reference...

The Guidelines provide for several approaches. They summarise the
underlying principles in a very broad sweep, so that the experienced and
the overconfident can simply draw their own conclusions about design.

There are 17 Guidelines, which the working group feels ought to be met -
each addressing a particular problem. (There is some overlap between
guidelines, but that's better than missing a problem)

Each guideline specifies a number of checkpoints - tasks which, when done,
will provide solutions to different problems (prioritised, according to an
external frame of reference).

These are all contained within the 'Guidelines document', which is in the
process of becoming a fixed reference of some kind.

There are two other documents produced by the Page Author Guidelines
Working Group:

A checklist of checkpoints. These are classified according to various
features - for example, all those dealing with form controls, or all those
dealing with dynamic interactive content, and further classified according
to priority.

There is also a techniques document. This explains in considerable detail
example solutions for the various problems.

This is my understanding of how it works.

Charles McCathieNevile

On Thu, 25 Feb 1999, Peter Munro wrote:

  My philosphy is to make a document that can be used as a quick reference
  and a learning document.
  
  Most people will try to fix separate prolems one at a time, before they
  learn how to fix all problems.
  
  Bobby testing software is setup this way.  Bobby test software shows all
  Priority 1 errors in groups.
  
  ALT TEXT  first and then the next error type next etc.
  
  It should be possible to change one type of error at a time by looking at
  the appropriate section.
  
  Here is a segment of what I am talking about.  I did not change very much
  of the existing text.  Much of the existing text has run on sentences, and
  lack definitions.
  
  
  An example of what I am talking about
  
  ---------------------------
  
    A.1 Provide alternative text for all images, applets, and image maps.
  
  Problem:
  
  Voice browsers and the visually impaired are unable to read
  
  - Images - submit, reset, bullets, 
  - Image Maps - This includes images with one or multiple links.  The cursor
  can not be put over the image.
  - Program Applets -Applets are unable to be read by
  early/freeware/shareware voice browsers.
  
  This includes images used as submit buttons, bullets in lists, and all of
  the links within an image map as well as invisible images used to layout a
  page. Alternative text does not describe the visual appearance of an image,
  applet, or image map. Rather, it is used to represent the function that the
  image, applet, or image map performs whether it be decorative, informative,
  or for purposes of layout. If alternative text is not provided, users who
  are blind, have low vision, or any user who cannot or has chosen not to
  view graphics will not know the purpose of the visual components on the
  page. Since "bare" ASCII art (characters that form images) does not allow
  alt-text, it must be marked up especially for this purpose
  
  
  Checkpoints:
  
     1.Provide alternative text for all images (e.g., in HTML, via the "alt"
  attribute of the IMG and INPUT elements, or via "title" or within the
  content of OBJECT). Note. This includes image used as image maps, spacers,
  and bullets in lists, graphical buttons and links. [Priority 1] 
     2.Provide alternative text for all applets and other programmatic
  objects (e.g., in HTML, via the "alt" attribute or within the content of
  APPLET, or via the "title" attribute or within the content of OBJECT). (See
  also A.11) [Priority 1] 
     3.For all image map links, provide alternative text for each link (e.g.,
  via the "alt" attribute of HTML AREA element). [Priority 1] 
     4.For all image map links, provide redundant textual links. [Priority 2]
  if client-side image maps are used, [Priority 1] for server-side. 
     5.Do not use an image map to create a set of buttons in a form. Instead,
  use separate buttons or images (accompanied by alternative text). [Priority
  2] 
     6.Replace ASCII art with an image and alternative text. [Priority 1] or
  [Priority 2] depending on the importance of the information (e.g., an
  important chart). Note. If the description of (important) ASCII art is
  long, provide a description in addition to alternative text. (See alsoA.2) 
  
  Solutions
  IMAGES
  The solution is ALT TEXT.  This is in the form ALT="Text description".  The
  Alt Text describes the image in words so that the message can be understood
  without the image.
  
  EXAMPLE
  
  <IMG SRC="filename.gif" ALT="Text Description " HEIGHT=Y WIDTH=X>
  
  < > - Everything within these brackets is the same command
  IMG SRC="filename.gif" - Put file filename.gif here.
  ALT="TEXT DESCRIPTION" - Put the text description of the image in the place
   of TEXT DESCRIPTION.
  HEIGHT=Y - Y= The Height of the image.  Y is an Integer.
  WIDTH=X  - X= The width of the image.  X is an Integer
  
  ??? Where does the location command go?  IE: Align commands?
  
  IMAGES WITH LINKS AND IMAGE MAPS
  The solution is ALT TEXT and text links.  Voice browsers must have an ALT
  TEXT description of the image and text links to follow.  The reason for
  this is the voice browsers can read images, and voice browsers are unable
  to move over an image to choose a link follow.  
  
  "PUT SAMPLE CODE HERE"
  
  APPLETS
  Applets allow for the additional of text description inside the applets.
  Most voice browsers are not able to read this information.  ALT TEXT is
  need by most people and should be included for all Appletts.  This is
  similar to ALT TEXT for IMAGES.
  
  
  What do you mean by bullets etc.
  
  
  The Program BOBBY says that SUBMIT and RESET do nto require ALT TEXT?
  
  
  
  
  

--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
MIT/LCS  -  545 Technology sq., Cambridge MA, 02139,  USA
Received on Thursday, 25 February 1999 16:57:20 GMT

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