W3C home > Mailing lists > Public > w3c-wai-gl@w3.org > April to June 2005

Proposal for Guideline 1.1

From: Wendy Chisholm <wendy@w3.org>
Date: Tue, 26 Apr 2005 22:35:27 -0400
Message-ID: <426EFA6F.5000705@w3.org>
To: wai-gl <w3c-wai-gl@w3.org>
Attached is an html file with the issue summary for Guideline 1.1 as 
well as proposed text for the guideline and related definitions. 

The proposal for the first criterion is really rough. Ideas welcome.  
"@@s" indicate questions. Comments related to issues and changes 
enclosed in {}

Best,
--wendy

===
Summary of issues

    * Issue 1486, issue 1487, issue 1488 - rewording proposals from the 
report on the impact of not setting a baseline.
    * Issue 1368 - GL 1.1, SC L1 - division of content isn't clear - 
propose that we handle this in the Guide. If that's not acceptable, 
perhaps add a paragraph to Guideline 1.1 that explains the differences 
between the criterion.
    * Issue 1369 - Commentor feels that example 4 was inadequate. See 
proposed wording below.
    * Issue 1433 - Commentor feels that context should determine the 
appropriate text alternatives for non-text content. Specifically cited 
example 4. Fixed example 4, but the issue is not addressed. perhaps this 
will be clarified in the guide?
    * Issue 1434 - Broken link. Overcome by events.
    * Issue 1075 - Text alternatives that are not explicitly associates 
are sometimes okay. I added a long note to this criterion. Not sure if 
it solves the issue.
    * Issue 791 - Clarification needed about the benefit of text 
alternatives for people who have difficulty reading text. Created a 
separate benefit to explain.
    * Issue 1439 - Guideline 1.1, Level 1, point 6 is needed. Deleted 
the editorial note that noted the similarities between criterion.
    * Issue 895 - To grossly oversimplify the issue, "is a noscript 
required for every script." Include scripted content in proposed 
definition of non-text content, text, and functional and slightly 
modified what is required for functional non-text content.
    * Issue 587 - Definitions needed for text alternative, text, 
unicode, non-text content, and ASCII art. Should also close issue 673.


Proposal for Guideline 1.1 Provide text alternatives for all non-text 
content.

Level 1 Success Criteria for Guideline 1.1

   1. For all non-text content that is functional text alternatives 
identify the non-text content in such a way that the label serves the 
same purpose as the non-text content. If the non-text content is a 
collection of functional non-text content, each function and collection 
of functions within is identified. [I] {Issue 1486 - Deleted the phrase: 
", such as graphical links or buttons" tried rewording to include web 
apps and widgets within web apps. This is probably not technically 
correct and could use a plain language rewrite.}

      How to provide text alternatives for content that is functional. 
(Informative)

   2. For all non-text content that is used to convey information, text 
alternatives convey the same information. [I]

      Note:      for multimedia, this means that two alternatives are 
provided:
         1. a transcript
         2. a text alternative that identifies the purpose or function 
of the multimedia

      How to provide text alternatives for content that conveys 
information. (Informative)

   3. For non-text content that is intended to create a specific sensory 
experience, such as music or visual art, text alternatives identify and 
describe the non-text content. [I]

      How to provide text alternatives for content that creates a 
specific sensory experience. (Informative)

   4. Non-text content that does not convey information, functionality, 
or create a specific sensory experience is implemented such that it can 
be ignored by assistive technology. [I] {Editorial: replaced "provide 
information" with "convey information" and added "create a specific" to 
"sensory experience" for consistency. Issue 1487 - replaced "marked" 
with "implemented.}

      How to provide text alternatives that can be ignored by assistive 
technology. (Informative)

   5. Any text alternatives are explicitly associated with the non-text 
content. [I]

      Note: At a minimum, a text alternative that serves the same 
purpose as the non-text content must be explicitly associated with the 
non-text content (per the first success criterion). However, if an 
additional text alternative is needed to understand the non-text 
content, it must be easy to find either because:
          * the additional text alternative appears immediately before 
or immediately after the non-text content [in reading order? in object 
model?] or
          * the additional text alternative is referred to in the 
explicitly associated text alternative or
          * the additional text alternative is itself explicitly 
associated. {Issue 1075 - Added the note in an attempt to clarify how 
and when text alternatives may not be explicitly associated with 
non-text content.}

      How to explicitly associate text alternatives with non-text 
content. (Informative)

   6. For live audio-only or live video-only content, such as internet 
radio or Web cameras, text alternatives describe the purpose of the 
presentation or a link is provided to alternative real-time content, 
such as traffic reports for a traffic Web camera

      Note: real-time content does not imply real-time captions. {Issue 
1439 - deleted editorial note, "Editorial Note: This is similar to #1 
above, yet it seems we need to specifically address audio-only and 
video-only content to avoid confusion.}

Level 2 Success Criteria for Guideline 1.1

   1. No level 2 success criteria for this guideline.

Level 3 Success Criteria for Guideline 1.1

   1. For multimedia content, a combined transcript of audio 
descriptions of video and captions is available. [I] {Issue 1488 - 
replaced "provided" with "available."}

      How to provide descriptions of all important visual information 
for multimedia. (Informative)

Who Benefits from Guideline 1.1 (Informative)

    * People who are blind, have low vision, or have cognitive 
disabilities can have text alternatives read aloud to them by assistive 
technology.
    * People who have trouble reading text may use tools that both read 
text aloud and highlight the words as they are read. In some cases, it 
may be difficult for someone to recognize visual information and the 
text alternative may help him or her understand the purpose of the 
non-text content. {Issue 791 - separated the 1st benefit into 2 to 
clarify how text alternatives may benefit people who have difficulty 
reading text.}
    * People who are deaf, are hard of hearing, or who are having 
trouble understanding audio information for any reason can read the text 
presentation or have it translated and presented as sign language by 
assistive technology.
    * People who are deaf-blind can read the text in braille.
    * Additionally, text alternatives support the ability to search for 
non-text content and to repurpose content in a variety of ways.

Examples of Guideline 1.1 (Informative)

    * Example 1: an image used as a button.
      A magnifying glass icon is used to link to the search page of a 
Web site. A screen reader identifies the button as a link and speaks the 
text alternative, "Search."

    * Example 2: a data chart.
      A bar chart compares how many widgets were sold in June, July, and 
August. The short label says, "Figure one - Sales in June, July and 
August." The longer description identifies the type of chart, provides a 
high-level summary of the data comparable to that available from the 
chart, and provides the data in a table.

    * Example 3: an audio recording of a speech (no video).
      The link to an audio clip says, "Chairman's speech to the 
assembly." A link to a text transcript is provided immediately after the 
link to the audio clip.

    * Example 4: a recording of a symphony.
      The Mars Philharmonic Orchestra's "Upcoming performances" page has 
a link to a 3 minute clip of the orchestra's rendition of Beethoven's 
5th Symphony. The purpose is to encourage readers to buy tickets to a 
live performance. The link to the audio clip says, "Beethoven's 5th 
Symphony performed by the Mars Philharmonic Orchestra." On the same page 
is information about Beethoven and the 5th Symphony. Elsewhere on the 
Mars Philharmonic Orchestra's Web site is an educational area. There is 
a link to the same 3 minute clip of the orchestra performing Beethoven's 
5th Symphony. The link is the same, "Beethoven's 5th Symphony performed 
by the Mars Philharmonic Orchestra." However, the page describes how 
this clip relates to the drama that Beethoven creates in his 5th 
symphony and describes a specific rhythm captured in this clip. It goes 
on to explain how this symphony "crystallized Beethoven's mature 
compositional innovations." (from Symphonies of Beethoven) {Issue 1369 - 
to clarify that in different situations a description may be provided 
and may be very different. Previously, there was no description, only an 
audio clip.}

    * Example 5: an animation that illustrates how a car engine works.
      An animation shows how a car engine works. There is no audio and 
the animation is part of a tutorial that describes how an engine works. 
All that is needed is a description of the image. From "How car engines 
work: Internal combustion"

    * Example 6: a pair of images used to create a visual effect.
      Two images are used to create curved edges on a "tab" interface. 
The images do not provide information, functionality, or a sensory 
experience and are marked such that they can be ignored by an assistive 
technology.

    * Example 7: an internet radio station.
      A radio station broadcasts over the internet. The station's Web 
site describes the type of music played, a schedule of the shows, and 
the "current song" is updated each time the DJ starts a new track. 
Interviews are recorded and published in the archives. Transcripts of 
the archived interviews are provided per Guideline 1.2 Provide 
synchronized alternatives for multimedia.
      Editorial Note: Does the above example help to clarify level 1 
success criterion 6 or does it need additional clarification?

    * Example 8: a traffic Web camera.
      A Web site allows end-users to select from a variety of Web 
cameras positioned throughout a major city. After a camera is selected, 
the image updates every 2 minutes. A short text alternative identifies 
the Web camera as, "TraffiCam." The site also provides a table of travel 
times for each of the routes covered by the Web cameras. The table is 
also updated every 2 minutes.

Proposals for definitions

Related to issue 587 (defn of text equiv/alternative) and issue 895 
(when to provide text alternatives for application-like non-text 
content, e.g., defn of non-text content)

ASCII art

        Proposed definition: An arrangement of characters intended to
    convey information. See non-text content. {Propose new definition to
    clarify that ASCII art is not text and is intended to "convey
    information"}

        Current definition: Graphic representations that are created by
    a spatial arrangement of text characters. Although it can be
    rendered on a text display, it is not text.


content

        Proposed definition: Information that forms Web sites and Web
    applications: the code and markup that define the structure,
    presentation, and interaction, as well as text, images, and sounds
    that convey information to the end-user. In this specification, the
    noun "content" is used in three ways:

           1. It is used to mean the delivery unit as a whole or in
    parts - the information that the author provides such that the user
    agent can generate an accessible perceivable unit(s).
           2. It is used to mean the perceivable unit(s) as a whole or
    in parts.
           3. It is used in the term non-text content.

        Current definition: none.

delivery unit

        Proposed definition: The information that the user agent
    receives and renders into a perceivable unit. {Editorial: Thought we
    might need a plain language version. Propose that if we use a plain
    language version, also include the more technically correct
    definition from the DI Glossary}

        Current definition: A set of material transfered between two
    cooperating web programs as the response to a single HTTP request.
    The transfer might, for example, be between an origin server and a
    user agent. [From Device Independence Glossary]

explicitly associated

        Proposed definition: Implemented in such a way that
    relationships can be programmatically determined. {Issue 1075 - new
    definition proposed to help clarify criterion}

        Current definition: none.

functionality

        Proposed definition: Performing or able to perform an action in
    response to user input.

        Current definition: Functionality is the purpose or intended
    effect of the content. This may include presentation of information
    , data collection, securing a response from the user, providing user
    experience, linking to other content, testing, confirmation,
    purchasing, etc.

non-text content

        Proposed definition: Content that is not represented by a
    Unicode character or sequence of Unicode characters

            * functional non-text content - content that is capable of
    performing an action in response to user input and is not text.
            * non-text content used to convey information - content that
    communicates an idea or data and is not text.
            * non-text content that is intended to create a specific
    sensory experience - arrangements of sounds, colors, forms,
    movements, or other elements in a manner that cause a reaction in
    the viewer or listener.

        Current definition:
        non-text content includes but is not limited to images, text in
    raster images, image map regions, animations (e.g., animated GIFs),
    ASCII art, images used as list bullets, spacers, graphical buttons,
    sounds (played with or without user interaction), stand-alone audio
    files, audio tracks of video, and video. It also includes any text
    that can not be translated into Unicode.
        Note:    Scripts, applets, and programmatic objects are not
    covered in this definition and are addressed in guideline 4.2.

perceivable unit

        Proposed definition: The result of a user agent rendering the
    contents of a delivery unit. User agents may or may not render all
    information in a delivery unit. In some cases, a single delivery
    unit may be rendered as multiple perceivable units. For example, a
    single html file that is rendered as a set of presentation slides.
    Most perceivable units contain presentation and the means for
    interaction. However, for some devices such as printers, a
    perceivable unit may only contain presentation. {An attempt at a
    plain language definition. Similar concern as to delivery unit.}

        Current definition: A set of material which, when rendered by a
    user agent, may be perceived by a user and with which interaction
    may be possible.
        User agents may choose to render some or all of the material
    they receive in a delivery unit as a single perceivable unit or as
    multiple perceivable units.
        Most perceivable units provide both presentation and the means
    for interaction. However, on some types of device, such as printers,
    perceivable units might contain only presentation. [From the Device
    Independence Glossary]

text

        Proposed definition: A sequence of characters. Characters are
    those included in the Unicode / ISO/IEC 106464 repertoire. Refer to
    Characters (in Extensible Markup Language (XML) 1.1) for more
    information about the accepted character range.

        [@@what about functional text content? e.g., links?] [@@refer to
    XML 1.0 or 1.1 - Christophe felt 1.0 is safer, but yet it's dated
    and not as "internationalized" - ala Richard's talk at the Technical
    Plenary]

        Current definition: none

text alternative

        Proposed definition: Text that is used in place of or in
    addition to non-text content. {Issue 587 - new definition for text
    alternative}

        Current definition:

            * serves the same function as the non-text content was
    intended to serve.
            * communicates the same information as the non-text content
    was intended to convey.
            * may contain structured content or metadata.

        Note: text alternatives should be easily convertible to braille
    or speech, displayed in a larger font or different colors, fed to
    language translators or abstracting software, etc.

unicode

        Proposed definition: Unicode is a universal character set that
    defines all the characters needed for writing the majority of living
    languages in use on computers. For more information refer to the
    Unicode Consortium or to Tutorial: Character sets & encodings in
    XHTML, HTML and CSS produced by the W3C Internationalization
    Activity. [Additional optional clarification: This does not mean
    that all documents should be encoded in Unicode. It means that
    documents should only contain characters defined by Unicode. Any
    encoding may be used for your document as long as it is properly
    declared and is a subset of the Unicode repertoire. ]

        Current definition: none.



-- 
wendy a chisholm
world wide web consortium
web accessibility initiative
http://www.w3.org/WAI/
/--



Received on Wednesday, 27 April 2005 02:35:53 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 5 February 2014 23:39:37 UTC