- From: Christophe Strobbe <christophe.strobbe@esat.kuleuven.be>
- Date: Wed, 15 Oct 2008 11:56:54 +0200
- To: WCAG <w3c-wai-gl@w3.org>
Hi, Two days ago, I taught a WCAG 2 introductory session to a small group of people who audit websites for accessibility. Here are a few questions and concerns that were discovered either during my preparation or the discussion we had. 1. Statement of partial conformance: <http://www.w3.org/TR/2008/CR-WCAG20-20080430/#conformance-partial> (A) This section says that 'The form of that statement would be, "This page would conform to WCAG 2.0 at level X if the following parts from uncontrolled sources were removed." ...' I assume that this would need to be followed by the other required parts of a conformance claim <http://www.w3.org/TR/2008/CR-WCAG20-20080430/#conformance-required>, but this is not stated. (B) This section also requires that the excluded content 'is described in a way that that users can identify (e.g. they can't be described as "all parts that we do not control" unless they are clearly marked as such.)' However, it is not clear where this description should be included: is it sufficient to only describe the excluded content in the conformance claim or should the excluded content also be identified in the conforming part of the content. For example, if you pull in image ads without alt text, what would you need to do? Which of the following would be sufficient? (b1) Conformance claim says that ads from ad server XYZ are excluded. Nothing special is done in the content. (Readers don't read conformance claims.) (b2) Conformance claim says that ads from ad server XYZ are excluded. In the web page, the text "advertisement" is added above or before every ad. (Readers don't read conformance claims.) (b3) Conformance claim says that ads from ad server XYZ are excluded. In the web page, the text "ads by XYZ" is added above or before every ad. (Readers don't read conformance claims.) (b4) Conformance claim says that ads from ad server XYZ are excluded. In the web page, the text "ads by XYZ" and a warning (or a link to the relevant section in the conformance claim) is added above or before every ad. 2. More info on how partial conformance and conformance requirement 5 interact would be welcomed. For example, if you have a page that triggers a semi-transparent Flash overlay (as an alternative to a pop-up prompt or a new window - e.g. for authentication) that traps the keyboard, and you exclude the Flash through a statement of partial conformance, does conformance requirement 5 still apply? In my opinion, the intent is that the conformance requirements still apply, but that is not clear from the section on partial conformance. According to our definition of "relied upon" the content still needs to conform if Flash is turned off or not supported, but I'm not sure if readers understand the implications of that definition. 3. The audience also asked if links to other media (PDF, audio, video) need to warn users in (or near) the link text (SC 2.4.4 Link Purpose (In Context) - Level A). Such a link would cause a change of context (3.2.2 On Input - Level A; 3.2.5 Change on Request - Level AAA), but who would include link activation in "Changing the setting of any user interface component" (SC 3.2.2) - even though the definition of user interface components includes links. 4. SC 1.4.2 Audio control <http://www.w3.org/TR/2008/CR-WCAG20-20080430/#visual-audio-contrast-dis-audio>: If there is a mechanism to pause or stop the audio or to control its volume, it is allowed to play automatically and for more than 3 seconds. This means that a screen reader user needs to find that mechanism while the audio is still playing, i.e. interfering with the speech output of his/her screen reader. So even content that passes this SC can interfere with the user's ability to use the whole page. 5. When I created a list of success criteria that apply to synchronised media, I found the following: SC 1.2.2 at Level A requires captions. If authors want to conform at Level AA, they also need to pass SC 1.4.4 (Resize text). If captions are implemented as text (closed captions), SC 1.4.4 applies to the captions, since there is nothing in the SC that says that captions are exempted. If video plugins don't have a resize functionality, this needs to be implemented in the content. Are there any plugins for video that can resize captions? If not, in which formats can authors implement functionality to resize text? (SMIL??) Best regards, Christophe -- Christophe Strobbe K.U.Leuven - Dept. of Electrical Engineering - SCD Research Group on Document Architectures Kasteelpark Arenberg 10 bus 2442 B-3001 Leuven-Heverlee BELGIUM tel: +32 16 32 85 51 http://www.docarch.be/ --- Please don't invite me to LinkedIn, Facebook, Quechup or other "social networks". You may have agreed to their "privacy policy", but I haven't. Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
Received on Wednesday, 15 October 2008 09:57:39 UTC