- From: Ben 'Cerbera' Millard <cerbera@projectcerbera.com>
- Date: Mon, 13 Aug 2007 15:08:43 +0100
- To: "HTMLWG" <public-html@w3.org>
- Cc: "Stephen Ferg" <ferg_s@bls.gov>
The research conducted a few years ago by Stephen Ferg [1] has been cited in public-html discussions previously [2]. Ian Hickson's reply [3] dismissed the headers="" techniques it suggested: > scope="" handles this fine. I've been having off-list discussions with Simon 'zcorpan' Pieters about header association in tables. "Nested row headers" [4][5][6] seem difficult to do in HTML with scope="" unless one re-arranges the cells to use rowspan="" or applies the headers+id technique. As such, I think Ian's conclusion may need revisiting for this case. I contacted Stephen Ferg about the opportunity for his research to shape HTML5. His response from 6th August 2007 is included here: [[[ The web site is http://stats.bls.gov The system that was eventually built on the basis of my original research is called TGS (Table Generation System). It is used to generate most of the regional tables on the BLS (Bureau of Labor Statistics) web site. (Currently we are adding the capability to TGS to generate tables in formats other than HTML: XML, PDF, and Excel.) The plan is for TGS eventually to be used to generate virtually all of the tables on the BLS site. The page for BLS region 5 (Chicago/midwest) is http://stats.bls.gov/ro5/ro5econ.htm If you click on just about any of the links, you will go to a page with TGS-generated tables. And of course there are pages for all 6 BLS regions. You can see an example of a TGS-generated table at http://stats.bls.gov/xg_shells/ro5xg01.htm As you can see, the far righthand headers are 3 deep: Percent change > 12 months ended > Jun 2007. In this table, note also the stub headings, which nest to 4 levels, e.g.:US City Average > Midwest Region > Midwest City Size Class > A. In the same table, note also the implementation of footnotes (footnote references jump to the footnote at the bottom of the table). This was the subject of one of my proposals. I've never done an automated analysis of the structure of the TGS production tables. (That might be interesting!) I'd say that most tables have two rows of headers. A smaller number (but still a substantial proportion) have one row, and a smaller number have 3 rows. TGS makes it easy to create tables with any desired number of levels of column headers, so the decision on how many levels of column headers is one of appropriateness, user-friendliness, and taste. -- Steve Ferg ]]] He has written up some other proposals for the authoring of HTML data tables [7]. His ideas have been applied to the genuine data on the Bureau of Labor Statistics's website for a few years. Even if you don't agree with the proposals, I think it's a valuable insight into how one educated content author is trying to work around limitations in the current table model. [1] <http://www.ferg.org/section508/accessible_tables.html> [2] <http://lists.w3.org/Archives/Public/public-html/2007May/1032.html> [3] <http://lists.w3.org/Archives/Public/public-html/2007May/1036.html> [4] <http://www.ferg.org/section508/accessible_tables_recommendations.html> [5] <http://sitesurgeon.co.uk/tables/clark2006/06-gui/> [6] <http://www.nsf.gov/statistics/gradpostdoc/94supp/sup19/txt/i2.htm> [7] <http://www.ferg.org/section508/htp00_proposal.html> -- Ben 'Cerbera' Millard Collections of Interesting Data Tables <http://sitesurgeon.co.uk/tables/readme.html>
Received on Monday, 13 August 2007 14:09:11 UTC