Re: Your comments on WCAG 2.0 Public Working Draft of May, 2007

Thank you for your comments

Although horizontal scrolling is a usability problem for the average
user, it is also an accessibility problem for many people with
disabilities because they are disproportionately affected by the
presence of horizontal scrolling.

People with cognitive disabilities, and professionals working with
them, have consistently told us that horizontal scrolling is a
problem.

Horizontal scrolling is very different for a low vision user who has
Assistive Technology (AT) such as Zoomtext, because the viewport in a
magnifier easily follows the movement of the mouse. This is a very
different experience from people who are not using AT. It is very
difficult to scroll back and forth without AT. And  one of the
criteria at AAA, is that there is greater weight put on accessibility
solutions that don't require AT.

Adjustable spacing between lines has been a consistent request from
people with cognitive disabilities and those working with them.
Originally, there were requests for double spacing but a consensus was
achieved among the commenters  that a minimum of 1.5 spaces was
acceptable. Professionals providing input on the need for adjustable
line height included The University of Dundee, Scotland department of
Human Computer Interface which focuses on HCI with Cognitive
Disability as the context, The Adaptec Project, Dawson College
Montreal, and the University of Colorado, Institute of Cognitive
Science. There are studies that support allowing for increased line
height such as:

MULTIFUNK: Bringing computer-supported reading one step further,
Date: April 2002,  ISBN: 82-539-0491-6, Author: Gjertrud W. Kamstrup,
Eva Mjøvik, Anne-Lise Rygvold og Bjørn Gunnar Saltnes

"Cognitive difficulties and access to information systems - an
interaction design perspective", Peter Gregor and Anna Dickinson,
Applied Computing, University of Dundee

"Case Study of a Dyslexic Person's Visual Perceptual Problems: A Fizz
Effect",  Nigel Beauchamp, IMPACT Research Group, Computer Science,
Loughborough University

"A Dyslexic Perspective on e-Content Accessibility" Peter Rainger,
Date of Publication: 20/01/03

In 9 years, we have received no requests from the disability community
for mandatory single line spacing or point increases of only 1-4.
Rehe's research is addressed to general usability, and is not
addressing computer interfaces. There is nothing in the wording of
this level AAA Success Criteria that prohibits single spacing, as long
as a mechanism is available to achieve 1.5 spaces.

Regards,

Loretta Guarino Reid, WCAG WG Co-Chair
Gregg Vanderheiden, WCAG WG Co-Chair
Michael Cooper, WCAG WG Staff Contact

On behalf of the WCAG Working Group

On Nov 6, 2007 6:46 AM, Liam McGee <liam@communis.co.uk> wrote:
>
> Dear Loretta, thanks for your response to my comment.
>
> The change does not deal with the problem raised in my original comment,
> thus I continue to be dissatisfied with this SC. I have modified my
> comments in the light of the revision you have made and re-presented
> them below. Hope they make sense... please email if clarification is
> required.
>
> The new SC 1.4.7 referred to in your response (appended at the end of
> this email); 1.4.8 in the Nov 2007 editor's draft; requires that for the
> visual presentation of blocks of text, a mechanism available to achieve
> the following:
>
>   "text is resized without assistive technology up to 200
>   percent in a way that does not require the user to scroll horizontally
>   to read a line of text "
>
> Problem 1:
> ----------
> Horizontal scrolling is not an accessibility issue (or, at least, I have
> no evidence that this is the case from experience with users with
> disabilities) - horizontal scrolling does not prevent a user from
> accessing information any more than vertical scrolling does. I am well
> used to scrolling all over the viewport when using screen magnification
> software, for example. This *is* a usability issue, but it does not
> prevent access to information.
>
> More critically, the need for horizontal scrolling depends on the
> pixel-width of the viewport, and this is *impossible for the designer to
> control*. A moderately long word (or a URL) on a PDA will easily fail
> this - and some languages have a lot of long words.
>
>
> Proposed Change:
> ----------------
> Suggested change: replace "in a way that does not require the user
> to scroll horizontally" with "while remaining readable to the user"
>
>
> Problem 2:
> ----------
> "line spacing is at least space-and-a-half within paragraphs,
> and paragraph spacing is larger than line spacing [LC- 569]"
>
> Query:
> ------
> I am interested in the research basis for this requirement.
>
> Leading/line height/line spacing is important to legibility but optimal
> leading is proportional to line length, and excessive leading has been
> shown to *diminish* legibility (Burt C. (1955): A Psychological Study of
> Typography; Cambridge University Press, Cambridge). Rehe's research
> suggested optimal leading ranges of 1 to 4 points, with heavier
> typefaces requiring more leading (Rehe RF (1974). Typography: how to
> make it most legible. Indiana: Design Research International).
> Many reviews of the area simply conclude that evidence is sketchy at
> best, and that more robust research (especially into on-screen
> legibility) is required.
>
> If we consider Rehe's argument that increasing beyond 1.4 reduces
> legibility, then 1.5 seems a funny number to pick. Of course, you may
> have some fantastic research to back up the 1.5 choice, but I'd be
> interested to know what it was.
>
>
> Many thanks, and keep up the good work
>
> Liam McGee
>
>
> Loretta Guarino Reid wrote:
> > ----------------------------------------------------------
> > Comment 1: Preferment of liquid over elastic design for accessibility reasons
> > Source: http://lists.w3.org/Archives/Public/public-comments-wcag20/2007Jul/0231.html
> > (Issue ID: 2356)
> > ----------------------------
> > Original Comment:
> > ----------------------------
> >
> > Firstly, the need for horizontal scrolling depends on the pixel-width
> > of the viewport. This is not under the designer's control
> >
> > Secondly, this is in any case problematic as a long word (or a URL) in
> > a columnar layout will easily fail this (loss of content as the layout
> > breaks). This may be even worse in languages where long words are a
> > common occurrence. In a layout context, it is saying "a word may not
> > be more than half the width of a column".
> >
> > Thirdly, horizontal scrolling is certainly a usability issue, but not
> > an accessibility issue - horizontal scrolling does not prevent a user
> > from accessing info (or at least, no more than vertical scrolling
> > does). I would rather scroll horizontally then have headings and URLs
> > become unreadable - which really is an accessibility issue. I am well
> > used to scrolling all over the viewport when using screen mag
> > software, for example.
> >
> > Proposed Change:
> > Suggested change: remove "and in a way that does not require the user
> > to scroll horizontally"
> >
> > ---------------------------------------------
> > Response from Working Group:
> > ---------------------------------------------
> >
> > We have addressed this problem in a different way. We have removed SC
> > 1.4.7 (Reflow). All the techniques from the success criterion are also
> > sufficient techniques for SC 1.4.4 (Resize text) and are listed there.
> > The other aspects of SC 1.4.7 are covered by a new success criterion
> > that addresses readability of text:
> >
> > "For the visual presentation of blocks of text, a mechanism is
> > available to achieve the following: (Level AAA)
> >
> >         * foreground and background colors can be selected by the user
> >         * width is no more than 80 characters
> >         * text is not aligned on both the left and the right [LC-1253]
> > [LC-569 (add)]
> >         * line spacing is at least space-and-a-half within paragraphs,
> > and paragraph spacing is larger than line spacing [LC- 569]
> >         * text is resized without assistive technology up to 200
> > percent in a way that does not require the user to scroll horizontally
> > to read a line of text "
>
>
>

Received on Tuesday, 11 December 2007 23:34:38 UTC