W3C home > Mailing lists > Public > public-comments-wcag20@w3.org > October 2008

Re: SC 3.2.5 vs. SC 2.2.4 and G75 and G76

From: Loretta Guarino Reid <lorettaguarino@google.com>
Date: Thu, 23 Oct 2008 18:37:18 -0700
Message-ID: <824e742c0810231837q47055700o8dae3b89e7640de4@mail.gmail.com>
To: sailesh.panchang@deque.com
Cc: public-comments-wcag20@w3.org

On Fri, Jul 25, 2008 at 9:50 AM, Sailesh Panchang
<sailesh.panchang@deque.com> wrote:
> Loretta,
> I beg to differ with the WG on this issue.
> A link that opens  up a presentation in a media player does cause a change
> in context but is a user initiated request (like the ones I stated in my
> email). Such links or UI elements will require advisory text like "launches
> in new window in media player" or the like. This link for instance cannot be
> turned  off as required by the "or" clause  of 3.2.5 because the content
> requires a player to display it. As the SC suggests, should the link be
> disabled or hidden if the user prefers not to view content in a media
> player?Perhaps the content and the player are fully accessible and no
> alternative rendering is available.
> User initiated change in context cannot cause an interruption because the
> user expects something to happen by activating an UI element. And advisory
> text would be a sufficient technique for this.
> Auto updating / refreshing content that is not user initiated is primarily
> an interruption which may also cause a change in context. Like a pop-up or
> the start  of a Flash presentation suddenly.
> (The techniques doc too refers to change in context caused by auto updating
> content while discussing G76).
> I would find 3.2.5 acceptable if it read:
> "Changes of context  are initiated only by user request."
> Causing a change in context  without prior notification when a UI element is
> activated by user is a failure of 3.2.5.
> I still think that G75 and G76 are no different.
> Sailesh Panchang
> Accessibility Services Manager (Web and Software)
> Deque Systems Inc. (www.deque.com)
> 11130 Sunrise Valley Drive, Suite #140,
> Reston VA 20191
> Phone: 703-225-0380 (ext 105)
> E-mail: sailesh.panchang@deque.com
> -----Original Message-----
> From: Loretta Guarino Reid [mailto:lorettaguarino@google.com]
> Sent: Thursday, July 24, 2008 10:34 PM
> To: sailesh.panchang@deque.com
> Cc: public-comments-wcag20@w3.org
> Subject: Re: SC 3.2.5 vs. SC 2.2.4 and G75 and G76
> On Thu, Jul 10, 2008 at 12:28 PM, Sailesh Panchang
> <sailesh.panchang@deque.com> wrote:
>> SC 2.2.4 Interruptions: Interruptions can be postponed or suppressed by
> the
>> user, except interruptions involving an  emergency. (Level AAA)
>> SC3.2.5 Change on Request:
>> Changes of context  are initiated only by user request or a  mechanism  is
>> available to turn off such changes. (Level AAA)
>> Comment:
>> 3.2 deals with making Web page content behave in predictable ways and the
>> emphasis is on consistent layout, navigation and identification. This is
> in
>> keeping with the "understanding" principle.
>> I believe a change in context caused by  auto updating content (3.2.5)  is
>> covered by interruptions (2.2.4) that  upset task focus. Such an
>> interruption or change in context makes it difficult to operate (or even
>> read) the Web page. So change of context by auto updating content is a
>> transgression of the "operate" principle than the "understand" principle.
>> Difficulty in understanding posed by auto updating content is a
> consequence
>> of difficulties posed during operation.
>> On the other hand, changes in context referred to 3.2.1 or 3.2.2 are also
>> unexpected but are based on user action (focus change / form input) and
>> certainly hamper understanding. As a consequence it makes operation
>> difficult.
>> The supporting techniques for 2.2.4 and 3.2.5 too are identical:
>> G75 for 2.2.4: Providing a mechanism to postpone any updating of content
>> G76 for 3.2.5: Providing a mechanism to request an update of the content
>> instead of updating automatically
>> I think this is just a play of words and  both SC 3.2.5 and technique G76
>> can be deleted without any  loss.
> ================================
> Response from the Working Group
> ================================
> While we agree that listing automatic updates under 3.2.5 (Change on
> Request) overlaps somewhat with the requirements of 2.2.4
> (Interruptions), the two do not overlap completely in that not all
> changes of context would be considered an interruption. For example,
> providing a link that causes a movie to be opened in a media player
> rather than in the current user agent would not be an interruption,
> but would be a change of context.
> Regarding G75 and G76, providing a mechanism that postpones or allows
> users to configure the frequency of automatic updates (G75) is
> different than providing a mechanism that allows users to manually
> request them (G76). You are correct however, that G76 should have been
> listed under 2.2.4 and we have corrected that error.
> 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

Response from the Working Group
The working group believes these are different.  An interruption
usually means that the user is returned to their original position
after the interruption ends.  A change of context generally would not.
So 2.2.4 wouldn't necessarily cover 3.2.5.  And 3.2.5 doesn't cover
2.2.4 because interruptions can take the form of a dialog box or other
event that doesn't necessarily change the context.

We do agree that these are very similar - and a single success
criterion might be constructed that would cover both.  But it is too
late in the process now to do this. And it would not change the
substance of the guidelines.

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
Received on Friday, 24 October 2008 01:37:59 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:11:11 UTC