Re: Proposed Sub-Heading Text for Guideline 8

It seems to me that searching is an example of a direct navigation technique.
Sequential navigation can also be done only on the basis of a structure,
which may (or in fact may not) be a hierarchy. On the Web, in a structured
language such as HTML or XML (even in poorly-written examples of the
language) navigating the structure which is defined by the formal syntax of
the language is a helpful strategy. 

In HTML in particular, there is an alternative strategy which is useful -
that of navigating certain types of elements. The two types of navigation
that are outside the formal structure, but still often useful, are navigation
of active elements to the exclusion of others (most browsers, including
internet explorer, lynx, netscape, opera, w3 and probably others, allow
this). The other is navigation by header elements. To my knowledge this is
part of opera and w3.  

It seems we should have a requirement for search navigation, and that it
should cover renderable content (which includes values of the alt and title
attribute, although we may need to define that explicitly since it is only
implicit in the document). We should also require some form of structure
navigation. I am not sure whether we should specify more than that as
requirements, although I would suggest that navigation of active elements
needs to be a distinct requirement, and that navigation of header elements be
a strongly recommended technique for structured navigation in HTML-reading
User Agents.

Charles McCN



On Fri, 30 Jul 1999, Jon Gunderson wrote:

  Guideline 8: Provide navigation mechanisms 
  
  JRG: Proposed Sub Head Text
  Users need to be able to navigate the web content.  Speech and Braille
  users especially need to have advanced navigation techniques, since speech
  and dynamic Braille displays offer only a temporal or very limited view of
  the document at one time.   Users need to be able navigate both active and
  non-active elements using strategies that support the users current
  familiarity of the document and the task they are trying to accomplish. The
  following are four basic types of navigation strategies user agents need to
  support:
  
  Sequential: Move sequentially between a set of element types based on the
  linear order of the element(s).  This type of functionality is important
  for exploring the contents of a new document.  The user knows they will
  view all elements that are part of the sequential navigation.
  
  Direct: Move directly between an element or a set of elements based on the
  element content or numerical position of the element.  This type of
  functionality is important for faster access to web content when they know
  the location of the information of interest.  This often happens when the
  user is using a frequently visited document.
  
  Searching: Search for an element based on element content or attributes.
  All elements or only a sub set of elements maybe part of the search.  This
  function is important to users that are looking for particular key words or
  other type of web content to efficiently identify if the information is in
  the document and move to the element containing the information.
  
  Hierarchical: Based on the document model tree move between the logical
  relationships between elements.  This type of navigation allows the user to
  efficiently move between logical units of the document.  This can be very
  useful for strongly structured documents like books or instructional
  materials.
  
  Jon Gunderson, Ph.D., ATP
  Coordinator of Assistive Communication and Information Technology
  Division of Rehabilitation - Education Services
  University of Illinois at Urbana/Champaign
  1207 S. Oak Street
  Champaign, IL 61820
  
  Voice: 217-244-5870
  Fax: 217-333-0248
  E-mail: jongund@uiuc.edu
  WWW:	http://www.staff.uiuc.edu/~jongund
  	http://www.als.uiuc.edu/InfoTechAccess
  

--Charles McCathieNevile            mailto:charles@w3.org
phone: +1 617 258 0992   http://www.w3.org/People/Charles
W3C Web Accessibility Initiative    http://www.w3.org/WAI
MIT/LCS  -  545 Technology sq., Cambridge MA, 02139,  USA

Received on Saturday, 31 July 1999 18:12:29 UTC