WCAG 2techniques for SC 1.3.2 and 2.4.3

Further to my email  on the same subject sent last week:
It appears from reading the 'understanding' material for SC 1.3.2 and 2.4.3, and associated techniques, that the expected reading order determined visually is key to identifying correct reading sequence from an accessibility standpoint.
G59(Placing the interactive elements in an order that follows sequences and relationships within the content) states:
"When the order of the HTML source matches the visual order of the Web page, tabbing through the content follows the visual layout of the content. When the source order does not match the visual order, the tab order through the content must reflect the logical relationships in the content that are displayed visually".
Then  C27: suggests making the DOM order match the visual order.
“The objective of this technique is to ensure that the order of content in the source code is the same as the visual presentation of the content”.
Then it goes on to describes  the problems  if the DOM order does not match visual order. These are  accurate and very valid. So if above stated objective is not attained, then does the content not fail the SC?  
Comment:
For every page there is only one intended  reading order and the author  sets out the page in that manner. This will generally be the order one might reasonably expect  based on a visual inspection of the page. The focus order of nav elements should follow that reading order.   
It is the user’s prerogative to read / navigate it in a different order if he so chooses. And he may do so because the alternate order helps him to better understand the content or simply because  only certain blocks of content  are of immediate relevance / interest. Proper structural markup would support this.  
If these techniques are to be applied to  make content comply with SC 1.3.2 then can one conclude that if actual reading and focus order do not follow expected visual order, then there is a problem and content fails SC 1.3.2 / SC 2.4.3?  

I agree that CSS can be used to change presentation. But it should not suggest a reading / focus order that is different from DOM / actual order that is programmatically determinable. 
   
Sailesh Panchang
Web Accessibility Specialist
www.deque.com

Received on Thursday, 14 October 2010 16:12:00 UTC