RE: REF 2.4b - a second required success criteria

This for disentangling these issues so nicely, Giorgio.

I think you've proposed a very interesting criterion for determining
when a "skip" link is required: if it takes longer to perceive and use
it than to tab through the links, the skip link is not an accessibility
feature: it's now a barrier!  

For me personally, a link for jumping over every group of three links
would be overkill-- "big time," as the kids say.  If there were a number
of such groups on the page, the additional skip links would add
significantly to the time it takes to hear the page and to the cognitive
overhead.  There was a brief period when the Hewlett-Packard site had a
skip link for every group of links, and I found it very frustrating.

John

John Slatin, Ph.D.
Director, Institute for Technology & Learning
University of Texas at Austin
FAC 248C
1 University Station G9600
Austin, TX 78712
ph 512-495-4288, f 512-495-4524
email jslatin@mail.utexas.edu
web http://www.ital.utexas.edu
 


-----Original Message-----
From: Giorgio Brajnik [mailto:giorgio@dimi.uniud.it] 
Sent: Sunday, July 13, 2003 6:04 am
To: w3c-wai-gl@w3.org
Subject: RE: REF 2.4b - a second required success criteria



Where does the seven comes from? Why 7 and not 5?
I don't think it has anything to do with Miller's 7 +/- 2 paper on short
memory. 

For example why shouldn't this apply to any group of links (where a
group may be as small 3, 4)? We could define the 'links group'  in terms
of performance: 

- how long does it take to perceive and interpret a 'skip links'
  button and activate it?  
versus
- how long does it take to perceive and interpret each link in a
  group, and tab over it?

If the link group is small enough that the time needed to skip over it
is higher than the time needed to tab through its links, then the group
size is too small.
 
John: do you think this might be a good rationale on how to determine
the group size to be mentioned in the success criterion?

LIFT detects navbars as small as 3 and suggests to wrap them within a
'skip links' button and named anchor. How would this behavior be
interpreted with respect to the suggested success criterion?


   Giorgio

John said:

  > Date: Wed, 9 Jul 2003 16:22:21 -0500
  > From: "John M Slatin" <john_slatin@austin.utexas.edu>
  > I agree that this is really important.  I'd propose a small
editorial
  > change in the wording as well as a slight change in the actual
criterion
  > (I'd like the requirement to be triggered when any group of links
  > includes 7 or more links, rather than just 8 or more...):
  >  
  > Proposed rewording (Gregg's original proposal is below for
reference):
  >  
  > "#2 Users are able to skip over navigational bars or other groups of
  > seven or more links when reading with a synthesizer or navigating
using
  > keyboard.

Received on Monday, 14 July 2003 09:20:33 UTC