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RE: How to make complex data tables more accessible to screen-reader users

From: Justin James <j_james@mindspring.com>
Date: Mon, 6 Jul 2009 14:08:32 -0400
To: <public-html@w3.org>, "'www-archive'" <www-archive@w3.org>
Message-ID: <11c801c9fe64$c61465a0$523d30e0$@com>
> -----Original Message-----
> From: public-html-request@w3.org [mailto:public-html-request@w3.org] On
> Behalf Of Shelley Powers
> Sent: Monday, July 06, 2009 1:26 PM
> To: Lachlan Hunt
> Cc: Sam Ruby; public-html@w3.org; www-archive
> Subject: Re: How to make complex data tables more accessible to screen-
> reader users
> So my own hypothesis is that when it comes to the authors, focusing
> purely on the markup is ineffective because any one of the solutions
> doesn't address the real problems: confusion about what needs to be
> provided, good, clear cut examples, and encouragement from the web
> community at large, and increased encouragement from the accessibility
> community.
> And again, the only way to really test this, objectively, is to get
> volunteers from the web community at large, develop tests for each of
> the approaches, have the people perform the tasks in controlled
> environments, observe the behavior, the results, and also provide
> questionnaires to test web authors preferences, understanding, etc.

Usability expert Jakob Neilsen has said on quite a number of occasions that
after doing tests on about 5 people, further tests refine the data, but the
overall direction is already well known. I believe that tests that you
describe do not need to be nearly as in depth, expensive, or as rigorous as
you describe. Remember, we're studying human behavior, and "in the lab"
behavior is much less important than actual "in the wild" behavior for our

Here is how I would go about a proper test of the "usability" of the HTML 5
spec regarding the @summary issue:

1. Put together a number of different spec texts regarding @summary, each
representing one of the many viewpoints on this subject. Put this text
within the context of a subsection of the HTML 5 table specs. So the only
difference between the table specs is the @summary information.

2. Gather a group of 5 - 10 volunteers for each of the proposed specs. Each
volunteer should be experienced with HTML 4, but have no connection with
this group (in other words, have none of the "context" around the @summary

3. Present each volunteer with a set of 3 - 5 tasks, involving table
creation. Give them an HTML template already made, so that all they need to
do is add the table. Each task should have the data that needs to go into
the table, and guidelines regarding captions/labels (but not explicitly say,
"use this caption"). For example: "Make a table showing the sales for each
of four different fruits. For each fruit, you know the name, country of
origin, number of pounds sold, price per pound, and total dollar sales
amount." That's it. No mention of accessibility, etc. Each volunteer may use
whatever tools they prefer (WYSIWYG editors, plain text editors, etc.).

4. Examine the HTML created by each group, and see if the users created a
table that truly meets the accessibility needs. Was @summary provided? Was
it truly useful? What about other basic table elements, like <th>? Were the
used appropriately?

5. Follow up with specific questions, such as "after reading the spec
provided, why did you chose to use @summary in the way that you did?" or
"what benefit do you expect @summary to provide to what kinds of users,
based on the spec that you read?"

I think that this would take no more than 1 hour of each volunteer's time,
could be conducted remotely (via a screen share, Web conference, phone call,
etc.) and therefore not require special usability labs, circumstances, etc.

> Accessing existing web pages is good for developing hypothesis, makes
> good anecdotal information, and can help determine where problems
> might arise. But it can't usefully be used to provide a definitive
> conclusion about what exactly is the root cause of the problems. Why?
> Because the data arises in the wild, not within a carefully controlled
> environment, where external factors can be filtered.

At the same time, for our purposes, "in the wild" results are the only ones
that matter in the end. Ian's "dry science fiction" phrase, and all of that.

> Sure, but I can't see this group being able to develop truly effective
> usability studies within the short time we have, and neither do I see
> any indication that we have the resources to conduct the proper tests.

I think the test I outlined above serves as a perfectly fine example. It
took me less than 10 minutes to devise and type up.

> I may be wrong: chairs, does the W3C have a usability lab?

You really do not need one for this circumstance. It is not like we are
doing eye tracking studies, need to record user interaction, time the tasks,
or any of the other items that a usability lab is used for.

> But you can't filter out all of the extraneous environmental factors
> when you're working with data in the wild.

I agree that you need to control as many factors as possible (which the test
I outline above does). At the same time, you need to study the way people
*actually* work, which means at their own desk on their own equipment, using
the workflow that they feel comfortable with. That's how a "listening lab"
works, instead of given the user precise instructions ("use the search
feature to find out the company's yearly revenues"), you provide the users
with a goal ("find the company's yearly revenues") and study how they go
about the task, listening to their narrative as they explain why they are
doing what they are doing.

> Even if we create a few web pages and ask people to try them out or
> try editing something and look at the results, we aren't conducting
> the study in a controlled environment, nor are we including safeguards
> to ensure bias doesn't creep into the result.

You are setting the bar not only far higher than it needs to be, but at a
level that actually invalidates the results.

> Normally, I don't think we would need this level of rigor, but when
> you have such a strong disagreement in the group, you have to go the
> extra distance to ensure truly comprehensive and inclusive results.

I agree, if for nothing else than to make sure that if the debate is not
actually ended, there is a set of data which we can at least all agree is
valid for discussion.

> But again--and I'm not sure I'm saying this clearly, so inviting
> others to rephrase or add to what I'm saying--we don't fully
> understand the root causes of the data that we do see.

I think that this is a fair assessment. The test I describe above makes sure
that the test subjects are fully informed regarding @summary, by providing
them with the relevant subset of the proposed HTML 5 spec, without
highlighting @summary to the point where subjects know what it is we are
looking for. At the same time, "all else is equal" (other than their work
environments), so we will be able to easily determine why @summary was or
was not used as needed.

Received on Monday, 6 July 2009 18:09:48 UTC

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