- From: Ben 'Cerbera' Millard <cerbera@projectcerbera.com>
- Date: Mon, 13 Aug 2007 17:04:29 +0100
- To: "HTMLWG" <public-html@w3.org>
As I understand it, HTML5's heading association algorithm [1] was designed to work with the most common data tables known at the time [2]. There is ongoing research from various Participants into gathering tables from the web to understand the ways authors are using them. Similar work is ongoing for how ATs enable users to interact with these tables (and other HTML structures). My initial thoughts from the tables I've seen (and the small proportion I have dissected in detail): 1. It's very common for data tables to have one or more rows of headers across the top of the table: a. 1 or 2 rows are both common. b. 3 rows happens less often but still enough to think about. c. More than 3 rows seems rare, although it does exist. d. When more than 1 row of column headers are used, headers in the higher rows tend to span several of the columns in the lower rows. 2. Row headers are done in various ways: a. Commonly, they are given a column header using <th> and are themselves using <th>. b. About as commonly as 2a, they use plain <td> and are given a column header using <th>. c. Occassionally there is an empty <th> or <td> at the top of the row headers column. The row headers then use <th>. 3. Data tables are sometimes found inside layout tables. 4. Data cells which are logically empty usually contain or some other placeholder which isn't really data. 5. Authors seem to use print media conventions when producing their tables. For example, <th colspan> which must replace any <th colspan> of the same width which occurs above it if there are <td> cells in between them. 6. The HTML4 algorithm [3] is rather vague but seems to handle a lot of cases. Do these observations match what other Participants see on the web? Is it OK if really strange cell arrangements which haven't provided scope="" or headers="" remain hard to use? Could those print media conventions be detected automatically? The aim of all this is for HTMLWG to produce a better table headers association thingy. But it's a complex subject. Let's work together to document the problems authors face before we carve anything in stone. :-) [1] <http://www.whatwg.org/specs/web-apps/current-work/multipage/section-tabular.html#header-and-data-cell-semantics> [2] <http://lists.w3.org/Archives/Public/public-html/2007Jun/1039.html> [3] <http://www.w3.org/TR/html4/struct/tables.html#idx-table-19> -- Ben 'Cerbera' Millard Collections of Interesting Data Tables <http://sitesurgeon.co.uk/tables/readme.html>
Received on Monday, 13 August 2007 16:16:24 UTC