Re: 'escape' method

This strikes me as a detailed description of why WCAG asks for links to be  
grouped. The original idea was that one could indeed simply jump out of  
the group - UAAG had a requirement that a user could navigate a document  
tree - so if there is a group of links in the tree they form a node, and  
the user can climb upand lok at the next or previous node instead. (Sorry  
to those who don't think in XML trees naturally - this might sound a bit  
strange).

Al, does it make sense that you are talking about how something like that  
ought to work in order to be helpful?

cheers

Chaals

On Fri, 15 Apr 2005 19:50:31 +0200, Al Gilman <Alfred.S.Gilman@IEEE.org>  
wrote:

>
> This expands on Jon's agenda item about what we are marking in the  
> content
> and the [range of] anticipated assistive processing including UA  
> behaviors
> that will be enabled by this markup.
>
> ** introductory overview
>
> Here I want to discuss two relaxations on the 'conventional wisdom' of  
> accessibility.
>
> a)  problem: from
>
> What it is we need to mark?  Groups of related links.
>
> to
>
> What it is we need to trap and mark up better?  Concentrations of  
> under-motivated links.
>
> b) solution: from
>
> Navigation destinations with Table-of-Contents -appropriate hint or  
> label or link text.
> .. supported by list and go-to methods..
>
> to
>
> Additionally an 'escape' or "get me out of here" method that
> - mimics the 'escapable structures' feature in DAISY books
> http://www.niso.org/standards/resources/Z39-86-2002.html#Escape
> - suffices to replace skip-nav links in the content
> - is similar to 'seek' functions in radio tuners and media players.
>
> ** discussion
>
> I call it 'escape' because it is available from anywhere within an  
> escapable structure, and
> not only from the beginning of that structure.  It moves you past some  
> current context
> that is of a class that the 'escape' method is proper to.  In DAISY this  
> is things like
> forms and tables.  I think that navbars would be another category that  
> this would
> be good for.
>
> Skip-nav can be achieved by using the 'escape' method when at the start  
> of the masthead.
> But we would have to look at what the actual algoritm is so it doesn't  
> take a confusing
> number of 'escapes' to get to the main content in that way.
>
> This solves a more general problem.
>
> The users who have trouble being lost in navbars will have a problem  
> wherever there
> is a high concentration of links that are under-motivated and  
> under-structured.
> The visual browsing experience allows rapid skimming of the scene, so  
> the usability
> is not broken by a shotgun blast of many links with loosely affiliated  
> context cues
> as to what the linked resources might add to the experience.
>
> The eyes-free user and the high-cost-per-input-symbol user both need  
> better
> structured ways to manage their review of the action opportunities  
> represented
> by the hyperlinks.
>
> Also, while the Table of Contents metaphor is very valuable in  
> organizing our work,
> navigating indirectly through the Table of Contents is by its  
> indirection less likely
> to be used.  In the talking book experience, the conventional wisdom is  
> that
> we need to serve users who will approach the content as a topic tree and  
> use
> the table of navigation, and also users who will play the book like a  
> serial tape and
> may need some skip or local navigation commands, but generally ignore the
> contents tree.
>
> I have been thinking we should try to adapt this bimodal use wisdom from  
> the book
> domain to the web page domain.
>
> There are of course limitations to the portability of the precedent.   
> Books are
> still, by and large, bigger than web pages.  And they are created in a  
> way that
> makes the table of contents more something that reflects the author's  
> mind
> than the way web pages get built.  But anyway, giving some way to skip  
> out
> of regions of rough sledding is an alternate model of what the assistive  
> function
> is that I think we should consider.
>
> Of course in the DAISY context we have high-political-correctness people
> (the alternate format edition producers) controlling the markup of  
> escapable
> sections.  So it makes sense to make the skip command move to the end
> of a marked section.  On the web we are not so fortunate.  So skipping to
> the first sign of lower link density is practial, if heuristic.
>
> What I am angling for here is that we take a reasonably low level of  
> assumed
> commitment from the authors, but still consider an 'escape' method that
> would be applicable to a) forms and tables without inspecting further  
> markup,
> and b) containers with 'roles' we designate as skippable, including  
> 'navigation.'
>
> Al



-- 
Charles McCathieNevile                      Fundacion Sidar
charles@sidar.org   +61 409 134 136    http://www.sidar.org

Received on Sunday, 17 April 2005 18:04:55 UTC