Re: UAAG2: Clarifying obscuration (SC 1.1.4.)

Hi Jan,

I had a few comments on this proposal--but don't feel pressured to respond while on vacation!

#1 Re the new sentence "Primary media not fully obscured: Alternative content for time-based media do not fully obscure the primary time-based media", relying on the term "fully obscure(d)" seems to be saying that it can block 1/2 or even 7/8 of the primary time-based media, as long as it doesn't block 100% of it, which doesn't seem appropriate. I believe your intention was to encourage modes where captions have transparent rather than opaque backgrounds, but I don't think that comes across.

#2 The two titles use different terms for the same thing: the first says "Alternative Content for Time-Based Media" where the second says "Time-Based Media Alternatives". While the former is unwieldy it is accurate, whereas the second could be describing alternative content that *is* time-based media, rather than alternatives to it. I suggest changing the title of 1.1.6 to match the style of the others, as in "Size and Position of Alternative Content for Time-Based Media" (unwieldy though it is), or else change to "time-based media alternatives" throughout.

#3 The first is explicitly limited to "on-screen" but the second is not. We probably want them both to use that phrase.

#4 A minor editorial point, but the equivalent of "above" is "to the right *of*" rather than just "to the right".

#5 Some of the clauses use wording that implies the requirement is "always on" rather than a user choice. For example, the clause "Alternative content for time-based media *do not* obscure recognized controls for the primary time-based media" seems to say that captions can never obscure the controls, whereas the user should be able to override that if they so choose, so the SC should not prohibit it. This can be addressed either by modifying the wording of the first sentence of the SC to clarify that /the user has to be able to have/ these behaviors, or by modifying list items b, c, and d to include similar wording (e.g. change "Alternative content for time-based media do not fully obscure the primary time-based media" to "the user can prevent alternative content for time-based media from...").

As I've noted before, ideally we should ensure that the wording for each SC reflects the right amount of "when". There are really five choices, all requiring that a behavior be available, but in addition representing the valid combinations of "may be/must be the default" with "must be/may be/must not be optional". I think three of the choices are currently used in UAAG 2.0:

 1. *Must* be available, *must not* be optional, *must* be default (It is very rare for software standards to intentionally make something mandatory or prohibited at all times.)

a.E.g. (from /Designing PCs and Peripherals////for the Microsoft Windows Systems/, 1996) Chromium and nickel are known to cause allergic reactions in some users and should therefore be avoided in any part that users could contact with their skin during normal use.

 2. *Must* be available, *may* be optional *must* be default

a.E.g. If the author has not specified a navigation order, the default sequential navigation order is the document order

b.E.g. By default, the user agent shows the progress of content retrieval

c.E.g. In its default configuration, the user agent does not display any user interface components or recognized content that flashes more than three times in any one-second period, unless the flash is below general flash and red flash thresholds

 3. *Must* be available, *must* be optional, *must* be default (This is often specified by a combination of one requiring a specific default and another requiring that the behavior be adjustable.)

a.E.g. (from ISO 9241-171) 10.4.5 Provide contrast between foreground and background: Default combinations of foreground and background colours (hue and luminance) of the software should be chosen to provide contrast regardless of colour perception abilities. 10.4.4 Allow users to individualize colour coding: Except in cases where warnings or alerts have been standardized for mission-critical systems (e.g. red = network failure), software should allow users to individualize colours used to indicate the selection, process, and the types, states and status of user-interface elements.

 4. *Must* be available, *must* be optional, *may* be default

a.E.g. The user can specify whether or not distinctions in the size of rendered text are preserved when that text is rescaled

 5. *Must* be available, *may* be optional, *may* be default

a.E.g. When the rendered content extends beyond the viewport dimensions, users can have graphical viewports include scrollbars.

b.E.g. The user can request a placeholder instead of executable content that would normally be contained within an on-screen area (e.g. Applet, Flash), until explicit user request to execute. (Note this wording is somewhat ambiguous, as some readers feel "can request" implies that it needs to be off by default, others that it needs to be optional.)


     Thanks,
     Greg

-------- Original Message --------
Subject: UAAG2: Clarifying obscuration (SC 1.1.4.)
From: Richards, Jan <jrichards@ocadu.ca>
To: w3c-wai-ua@w3.org <w3c-wai-ua@w3.org>
Date: 8/2/2013 11:56 AM
> On Thursday's call today I took an action to update  1.1.4 so that it wouldn't contradict the new definition of "obscure" that we agreed on the call:
> - Obscure: To render a visual element in the same screen space as a second visual element in a way that prevents the second visual element from being visually perceived. Note: While the use of transparent backgrounds for the overlaying visual element (e.g., video captions) is an acceptable technique for reducing obscuration, if space is available it is more effective not to overlap visual elements that are both of interest to the user.
>
> BTW: I also looked up where "obscure" came from in UAAG 1.0 and it actually had to do with video obscuring captions, not captions obscuring video (http://www.w3.org/TR/WAI-USERAGENT/guidelines.html#tech-configure-captions).
>
> ALSO I realize that the two bullets in 1.1.6 need handles:
>
> Here are my proposals:
>
> PROPOSAL 1:
>
> 1.1.4 Display of Alternative Content for Time-Based Media: For recognized on-screen alternative content for time-based media (e.g.
> captions, sign language video), the following are all true: (Level AA)
> (a) Text configurable: The user can configure recognized text within alternative content for time-based media (e.g. captions) in conformance with 1.4.1,
> (b) Alternatives not obscured: Alternative content for time-based media is not obscured by the primary time-based media,
>       [ed. Maybe obvious, but added for completeness - transparency is not an option]
> (c) Controls not obscured: Alternative content for time-based media do not obscure recognized controls for the primary time-based media, and
>       [ed. transparency is not an option]
> (d) Primary media not fully obscured: Alternative content for time-based media do not fully obscure the primary time-based media.
>       [ed. This is where transparency is allowed...then 1.1.6 requires a non-overlapping option]
>
> PROPOSAL 2 : Add handles  (marked with CAPS and @)
>
> 1.1.6 Size and Position of Time-Based Media Alternatives: The user can configure recognized alternative content for time-based media (e.g. captions, sign language video) as follows: (Level AAA)
> -@RESIZE: The user can resize alternative content for time-based media up to the size of the user agent's viewport.
> -@REPOSITION: The user can reposition alternative content for time-based media to at least two of the following: above, below, to the right, to the left,
> and overlapping the primary time-based media.
>   - Note 1: Depending on the screen area available, the display of the primary time-based media may need to be reduced in size or hidden to meet this requirement.
> - Note 2: Implementation may involve displaying alternative content for time-based media in a separate viewport, but this is not required.
>
>
> ----
> CURRENT WORDINGS (from http://lists.w3.org/Archives/Public/w3c-wai-ua/2013JulSep/0018.html):
>
> 1.1.4 Display of Alternative Content for Time-Based Media: For recognized on-screen alternative content for time-based media (e.g.
> captions, sign language video), the following are all true: (Level AA)
> - Don't obscure controls: Displaying time-based media alternatives doesn't obscure recognized controls for the primary time-based media; and
> - Don't obscure primary media: The user can specify that displaying time-based media alternatives doesn't obscure the primary time-based media; and
> - Use configurable text: The user can configure recognized text within time-based media alternatives (e.g. captions) in conformance with 1.4.1.
> Note: Depending on the screen area available, the display of the primary time-based media may need to be reduced in size to meet this requirement.
>
> 1.1.6 Size and Position of Time-Based Media Alternatives: The user can configure recognized alternative content for time-based media (e.g. captions, sign language video) as follows: (Level AAA)
> - The user can resize alternative content for time-based media up to the size of the user agent's viewport.
> - The user can reposition alternative content for time-based media to at least two of the following: above, below, to the right, to the left,
> and overlapping the primary time-based media.
>   - Note 1: Depending on the screen area available, the display of the primary time-based media may need to be reduced in size or hidden to meet this requirement.
> - Note 2: Implementation may involve displaying alternative content for time-based media in a separate viewport, but this is not required.
>
>
>
> Cheers,
> Jan
>
>
> (MR) JAN RICHARDS
> PROJECT MANAGER
> INCLUSIVE DESIGN RESEARCH CENTRE (IDRC)
> OCAD UNIVERSITY
>
> T 416 977 6000 x3957
> F 416 977 9844
> E jrichards@ocadu.ca
>
>
>