Re: [techs] The TH Rule

1. Bruce writes:
>Skilled use of HEADERS and ID should also work, so is >there harm in declaring that mixed tables are data tables?
Some e-commerce sites and airline sites etc make use of mixed tables that really confound users. I have seen a table  wherein the first few rows need to be navigated as a layout table then the next set of rows make a data table and use colspan. Then this sequence is repeated over the next set of rows till the end. All of this is just one table. One can assign  just one summary for the entire table - not for different sections. So how does a screen reader figure out when to use table navigation keys and when not to? And using table nav keys to go to first cell or last cell , works on the entire table and not the  section  which is a data table.

So one needs to discourage the practice of using  mixed tables.
2. Although caption is visible text unlike summary, it really helps to distinguish    data tables and is good for accessibility. Also enhances usability. Any data table without a caption is just bad practice as any book on Statistics 101 willsay. And if style can be used to change the display characteristics of  a th, why not use style to  make the caption  not show up visibly  if the author so desires? (See table 1 in attached file). One can set  style="display:none" to hide the caption but JAWS recognizes it.

  
3. For screen reader behavior of row with td only and row with td and scope:
Please see attached htm file. First table uses td for first row  and first col. Only JAWS reads row and col headers. But WinEyes 4.5 and HPR 3.02 do not read the col or row headings. headings.

 In the second table that uses  scope for first row and first col, JAWS and HPR reads  the headings correctly but WinEyes does not support  scope and does not read any headings.
Thanks,
Sailesh Panchang
Senior Accessibility Engineer 
Deque Systems,11180  Sunrise Valley Drive, 
4th Floor, Reston VA 20191
Tel: 703-225-0380 Extension 105 
E-mail: sailesh.panchang@deque.com
Fax: 703-225-0387
* Look up <http://www.deque.com> *