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Re: CHANGE PROPOSAL: Table Summary

From: Ian Hickson <ian@hixie.ch>
Date: Sun, 6 Dec 2009 13:59:11 +0000 (UTC)
To: Laura Carlson <laura.lee.carlson@gmail.com>
Cc: HTML Accessibility Task Force <public-html-a11y@w3.org>, Roger Johansson <roger@456bereastreet.com>
Message-ID: <Pine.LNX.4.62.0912061336050.24966@hixie.dreamhostps.com>
On Sun, 6 Dec 2009, Laura Carlson wrote:
> Ian wrote:
> > Nobody has collected equivalent data showing summary="" is useful at 
> > improving accessibility in practice,
> Last month Roger Johansson asked on his blog, "Do you find table 
> summaries helpful?"[1]. and received three responses from screen reader 
> users.
> [1] http://www.456bereastreet.com/archive/200911/do_you_find_table_summaries_helpful/

Interesting stuff.

I've commented on the responses below, but I should first say that it is 
well-established that asking questions in usability studies leads to 
results that are dramatically biased towards a supportive answer (e.g. if 
we ask people in Google usability studies whether they'll like a 
particular feature we're adding, they'll almost universally say yes, even 
though objective studies of their behaviour can show that they do not use 
the feature at all, or rarely benefit from it when they do). I would not 
be at all surprised if the same kind of non-self-aware reporting affected 
questions of this nature also.

Also, it's important to remember that nobody (as far as I know) is arguing 
that table explanations are undesireable -- the question is only one of 
what markup mechanism is most likely to lead to the highest rate of 
accessible tables overall. In other words, not "should we have summary 
information", but "how can we maximise the number of users who can make 
use of tables".

Now, notwithstanding my admission that the results are likely not ideal 
for drawing conclusions from, the comments do lead to some interesting 

 - comment 2 suggests that we should just make the explanatory text be 
   part of the captions

 - comment 3 agrees that explanatory text is helpful, but doesn't make any 
   assertion regarding how they should be presented

 - comment 4 reports that the quality of explanatory text varies wildly, 
   and suggests that better education of authors might be the way forward, 
   without making any assertion regarding what the markup should be

(Only two of the comments were actually from screen reader users, by the 
way; the first was reporting from memory the results of another study.)

> Some questions:
> Would it in-scope for this task force to do similar survey of screen 
> reader users on a wider scale? Would such a survey help bring this issue 
> to resolution? If so, are there any accessibility task force members 
> willing to collaborate on such a survey? Could the W3C WBS survey tool 
> be used for such a survey?

I'm not sure that a survey would be the best way of collecting data about 
the best way to improve accessibility. I think a better way to get data 
about this would be a set of usability studies of Web authors followed by 
double-blind studies of the pages they write. For example, take six to 
nine Web developers, and give them the task of marking up some Web pages 
that include particularly complex data tables in an accessible way that is 
still aesthetically pleasing to them. The developers would be split into 
three groups, one being given instructions on using summary="", one being 
given instructions on writing paragraphs around the table, and one being 
given no instruction at all. Then, take the resulting pages, and bring in 
six to nine users of assistive technologies, and randomly give each one 
some of the pages created, and ask them to fill in a questionnaire based 
on the data in the table. Then, a researcher who is not aware of any of 
these events is asked to "grade" the questionaires, and determine which 
show a better understanding of the underlying data.

This I think would most effectively demonstrate whether one method or 
another is better.

I think it would be fantastic if we could do this. If people agree that 
this is a reasonable thing to do, I might (emphasis on "might") be able to 
get the resources to do this early next year.

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Sunday, 6 December 2009 13:59:40 UTC

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