W3C home > Mailing lists > Public > public-wai-ert@w3.org > March 2008

ERT WG clarification on comments by Carlos Iglesias (CTIC) on SC 1.4.8

From: Carlos Iglesias <carlos.iglesias@fundacionctic.org>
Date: Mon, 31 Mar 2008 14:15:56 +0200
Message-ID: <09700B613C4DD84FA9F2FEA521882819033110AA@ayalga.fundacionctic.org>
To: "Loretta Guarino Reid" <lorettaguarino@google.com>
Cc: <public-comments-WCAG20@w3.org>, <public-wai-ert@w3.org>


Dear WCAG WG,

This message is a follow-up clarification on the exchange between Carlos Iglesias and WCAG WG on SC 1.4.8 [1]. While these comments were initially sent on behalf of CTIC, the ERT WG has been following the discussion and has also discussed some of the issues from an evaluator's perspective.

After a closer review of this issue regarding a width of 80 characters, the ERT WG has come to the conclusion that this requirement could be adequately tested using manual procedures. For example by resizing the browser window and counting the characters, as you suggested.

So the problem we see is not so much with the requirement itself, but with the associated techniques. More concretely, the Quick Reference document [2] describes Technique C20 "Using relative measurements to set column widths so that lines can average 80 characters or less when the browser is resized" [3] as a Sufficient Technique to meet this requirement, but we do not think satisfies it.

We also do not fully understand what WCAG WG means with the first option "Not interfering with the user agent's reflow of text as the viewing window is narrowed (General, Future Link)" and can therefore not judge how easy it would be to test for the overall requirement. We do however acknowledge that the Quick Reference and Techniques documents are still under development, and that they will be refined in the future.

To summarize, we have no objections to the responses of WCAG WG made on the Success Criteria level, and think that WCAG 2.0 can proceed with the provision as currently stated. We do however want to raise an issue on the techniques layer, which we believe needs further work to facilitate the evaluation of this specific 80-character requirement.

[1] - <http://lists.w3.org/Archives/Public/public-comments-wcag20/2008Mar/0092.html>
[2] - < http://www.w3.org/WAI/WCAG20/quickref/20080310/Overview.php#qr-visual-audio-contrast-visual-presentation>
[3] - <http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-TECHS/C20.html>

Thanks again for your hard work on this,
  CI on behalf of the ERT WG and CTIC.

____________________

Carlos Iglesias

Fundación CTIC
Parque Científico-Tecnológico de Gijón
33203 - Gijón, Asturias, España

teléfono: +34 984291212
fax: +34 984390612
email: carlos.iglesias@fundacionctic.org
URL: http://www.fundacionctic.org


> -----Mensaje original-----
> De: Loretta Guarino Reid [mailto:lorettaguarino@google.com]
> Enviado el: sábado, 22 de marzo de 2008 0:19
> Para: Carlos Iglesias
> CC: public-comments-WCAG20@w3.org
> Asunto: Re: Your comments on WCAG 2.0 Last Call Working Draft of December,
> 2007
> 
> On Tue, Mar 18, 2008 at 9:09 AM, Carlos Iglesias
> <carlos.iglesias@fundacionctic.org> wrote:
> >  > ----------------------------------------------------------
> >  > Comment 1: Concerns about 80 characters width limit
> >
> > > Source: http://lists.w3.org/Archives/Public/public-comments-
> >  > wcag20/2008Feb/0046.html
> >  > (Issue ID: 2497)
> >
> > > Status: VERIFIED / PARTIAL/OTHER
> >  > ----------------------------
> >  > Original Comment:
> >  > ----------------------------
> >  >
> >  > Having into consideration that the number of characters per line may
> >  > be affected by different parameters (window size, screen resolution,
> >  > font-size...) that are not controllable by the content creator, this
> >  > requirement may be quite difficult (not to say impossible) to
> fulfill.
> >  >
> >  > Additionally readability may be also equally affected when the line
> >  > width is to narrow, so I don't understand why to put just top limits
> >  > in case of put any.
> >  >
> >  > ---------------------------------------------
> >  > Response from Working Group:
> >  > ---------------------------------------------
> >  >
> >  > First, it should be noted that if the author does not set the column
> >  > width but lets the text wrap as it will, then he satisfies this
> >  > success criterion. It is only when authors set the column width to
> >  > fixed values that are more than 80 characters wide that a problem
> >  > arises.  Note that the success criterion says, "a mechanism is
> >  > available".  It is only when the author defines font and column width
> >  > etc. in such a way that the user cannot achieve an 80 character line
> >  > length that the author creates a problem.
> >
> >  Then an author can not set any column width at Level AAA, because the
> suggested technique of using ems width for columns doesn't work as it is
> shown in the following test case:
> >
> >  [http://www.fundacionctic.org/uaw/test-cases/em-width/test.html]
> >  [http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-TECHS-20080310/C20.html]
> >
> >  Note that every paragraph in the test case has a width of 80 ems, but
> the number of characters per line varies depending mainly on the font
> family.
> >
> >  No one of the text samples has 80 characters per line, not even near to
> them, so it is apparently clear that ems widths can not be used to set a
> column width of any specific number of characters in a reliable way.
> >
> > ----------------------------------------------------------
> 
> Thank you for pointing out the errors in the examples and description
> of this technique. We have revised the technique in a number of ways
> to address these concerns.
> 
> Refer to http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-TECHS/C20.html for
> the updated technique.
> 
> Note that the test for successful implementation of this technique
> only requires that line length can be set to 80 characters or less by
> resizing the browser window, not that they be 80 characters or less in
> all circumstances, so the concerns you mention regarding the
> variations in the number of characters in a column based on
> font-family settings would not have an impact on whether this
> technique has been successfully implemented.
Received on Monday, 31 March 2008 12:17:02 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 31 March 2008 12:17:03 GMT