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Re: review of section 6

From: Charles McCathieNevile <charles@w3.org>
Date: Tue, 23 Feb 1999 20:00:45 -0500 (EST)
To: WAI UA group <w3c-wai-ua@w3.org>
Message-ID: <Pine.LNX.4.04.9902232000330.10835-100000@tux.w3.org>
On Tue, 23 Feb 1999, Charles McCathieNevile wrote:

  I have interspersed my comments between (often lengthy) chunks of the
  document (look for CMN:). Where I don't see any problems, I have left out
  the relevant excerpt (look for SNIP)
  
    6.1 Provide information about the document view
            
     Users that are viewing documents through linear channels of perception
  like speech (since speech is temporal in nature) and tactile displays
  (current tactile technology is limited in the amount of information that
  can be displayed) have difficultly maintaining a sense of their relative
  position in a document. The meaning of "relative position" depends on the
  situation. It may mean the distance from the beginning of the document to
  the point of regard (how much of the document has been read), it may mean
  the cell currently being examined in a table, or the position of the
  current document in a set of documents.
  
     For people with visual impairments, it is important that the point of
  regard remain as stable as possible. For instance, when returning to a
  document previously viewed, the user's previous point of regard on the
  document should be restored. The user agent should not disturb the user's
  point of regard by shifting focus to a different frame or window when an
  event occurs without notifying the user of the change. Disturbing the
  user's point of regard may cause problems for users who have movement
  impairments, who are blind, who have visual impairments, who have certain
  types of learning disabilities, or for any user who cannot or has chosen
  not to view the authors representation of information.
  
  CMN: This paragraph (above) could be significantly trimmed without losing
  any content.
       
  SNIP
  
     6.1.9 [Priority 2]
            When a document is loaded or when requested by the user, make
  available document summary information. 
  
  CMN: This is too vague. What information is required?
    
     6.1.11 [Priority 3]
            Provide the user with information about document loading status
  (e.g., whether loading has stalled, whether enough of the page has loaded
  to begin navigating, whether following a link involves a fee, etc.)
  
  CMN: This is also very vague. Perhaps this should be combined with 6.1.9,
  and made explicit as to what tyes of information are required.
  
    6.2 Provide information about document structure
   
     Hierarchical navigation (through the document tree) is useful for
  efficiently navigating the major topics and sub-topics of a document.
       
     6.2.1 [Priority 2]
            Allow the user to view a document outline constructed from its
  structural elements (e.g., from header and list elements).
  
     6.2.2 [Priority 2]
            Allow the user to navigate the document tree.
     
     6.2.3 [Priority 2]
            Allow the user to navigate sequentially among headers.
  
     6.2.4 [Priority 2]
            Allow the user to navigate sequentially among block elements
  (e.g., paragraphs, lists and list items, etc.)
     
     6.2.5 [Priority 2]
            Allow the user to search for an element in the current document
  based on its text content. In case of a match, the selection should be
  moved to the element.
  
  CMN: This section could be structured much better.
  
  The checkpoints are, so far as I can see, as follows:
  
  1. Allow the user to navigate the document's structural tree [p2]
  
  2. Allow the user to generate and navigate a tree based on teh semantics
  of a DTD [p3]
  
  Technique: For an HTML document, construct a tree where headers are
  considered children of preceding headers with greater priority, and
  block-level elements are considered children of headers. Amaya does
  something like this in its 'outline' view.
  
  3. Allow the user to search for content. In case of a match, move the
  selection to the content [p2]
  
  4. Allow the user to search for an element, by specifying text content or
  the content of descriptive attributes (eg TITLE, ALT). In case of a match,
  move te selection to the element [p3]
      
    6.3 Provide information about events
            
     It is important to alert users, in an output device-independent
  fashion, when important events occur during a browsing session. To avoid
  confusion that the effects of scripts may cause, users should be notified
  when scripts are executed (or be able to disable scripts entirely). This
  is also important for security reasons; users should be able to decide
  whether to allow scripts to execute on their machines.
            
     6.3.1 [Priority 1]
            Allow the user to navigate among elements with associated event handlers.
  
  CMN: Is this relevant to UAs which do not handle the events? I suspect
  not. Should it apply to navigating the children of an element which
  handles bubbled events? I suspect so. All Children? Harder to say.
  
     6.3.2 [Priority 2]
            Alert the user when scripts or applets are executed.
            
     6.3.3 [Priority 3]
            Provide information about document changes resulting from the
  execution of a script.
  
  CMN: I suggest that 6.3.2 and 6.3.3 be rewritten as follows:
  
  1. Provide notification of content and structure changes to the Document
  Object Model. [p1]
  
  2. Provide notification of style changes to the Document Object Model.
  [p2]
  
  3. Provide information about content and structure changes to the Document
  Object Model. [p2]
  
  4. Provide information about style changes to the Document Object Model.
  [p3]
  
  Charles McCN
  --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
  
  

--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 Tuesday, 23 February 1999 20:00:47 GMT

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