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Comments on W3C mobileOK Basic Tests 1.0 January 2007

From: Christophe Strobbe <christophe.strobbe@esat.kuleuven.be>
Date: Tue, 13 Feb 2007 15:55:13 +0100
Message-Id: <>
To: public-bpwg-comments@w3.org


Below are a few comments and questions about the working draft [1].

* 3.1 AUTO_REFRESH (partial) and REDIRECTION
The draft states: "This test does not determine whether the user is 
able to opt out of refresh."
Is the possibility of opting out going to be covered elsewhere?
Using <meta http-equiv="refresh" content="..." /> fails three 
different success criteria of the Web Content Accessibility 
Guidelines 2.0 (see failure F40 in "Techniques for WCAG 2.0" [2]). 
This is because screen readers will start reading from the top of the 
page again when the page refreshes, thereby taking away control from 
the user over his interaction with a page.
Server-side redirects [3] are preferable, but WCAG 2.0 currently also 
allows client-side redirects if they have no timeout: see techniques 
G110 (Using an instant client-side redirect [4]) and H76 (Using meta 
refresh to create an instant client-side redirect [5]).

Note that the if statements for the meta element and the HTTP refresh 
header are different: one refers to "the current resources's URI", 
while the second refers to "the current page". Shouldn't the same 
wording be used in both cases?

People are aware of validators for HTML, XHTML and CSS, but how do 
you check if an image is valid according to GIF89A or JPEG? Do image 
editors check this or do they just check whether the images are "good 
enough" for the editor? Could you provide pointers to tools that are 
reliable "validators" for GIF89A and JPEG?

This prohibits the definition of image size in style sheets [6]. Is 
that intentional or an oversight?

* 3.14 NON-TEXT_ALTERNATIVES (partial)
The draft states: "This test does not determine whether the 
alternative text is meaningful." Why not? Doesn't a meaningless text 
alternative defeat the purpose of the alt attribute?
Note that the current working draft of WCAG 2.0 requires: "text 
alternatives serve the same purpose and present the same information 
as the non-text content. If text alternatives cannot serve the same 
purpose, then text alternatives at least identify the purpose of the 
non-text content" (this is just part of success criterion 1.1.1 [7]).

* 3.24 TABLES_LAYOUT (partial)
The draft states: "This test does not catch all cases where tables 
are used for layout purposes." I agree. "Techniques for WCAG 2.0" 
also has a test for layout tables [8]:
"Check for layout tables: determine whether the content has a 
relationship with other content in both its column and its row. If 
'no,' the table is a layout table. If 'yes,' the table is a data table."
Would that be a better fit? Obviously, the test from WCAG 2.0 cannot 
be automated.

[1] http://www.w3.org/TR/2007/WD-mobileOK-basic10-tests-20070130/
[2] http://www.w3.org/TR/2006/WD-WCAG20-TECHS-20060427/Overview.html#F41
[3] http://www.w3.org/TR/2006/WD-WCAG20-TECHS-20060427/Overview.html#SVR1
[4] http://www.w3.org/TR/2006/WD-WCAG20-TECHS-20060427/Overview.html#G110
[5] http://www.w3.org/TR/2006/WD-WCAG20-TECHS-20060427/Overview.html#H76
; http://www.bigbaer.com/css_tutorials/css.scale.image.html.tutorial.htm
[7] http://www.w3.org/TR/2006/WD-WCAG20-20060427/complete.html#text-equiv-all
[8] http://www.w3.org/TR/2006/WD-WCAG20-TECHS-20060427/Overview.html#H39-tests

Best regards,

Christophe Strobbe

Christophe Strobbe
K.U.Leuven - Departement of Electrical Engineering - Research Group 
on Document Architectures
Kasteelpark Arenberg 10 - 3001 Leuven-Heverlee - BELGIUM
tel: +32 16 32 85 51

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
Received on Tuesday, 13 February 2007 14:55:20 UTC

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