Your comments on WCAG 2.0 Last Call Draft of April 2006 (1 of 2)

Dear Eric Hansen ,

Thank you for your comments on the 2006 Last Call Working Draft of the
Web Content Accessibility Guidelines 2.0 (WCAG 2.0 We appreciate the
interest that you have taken in these guidelines.

We apologize for the delay in getting back to you. We received many
constructive comments, and sometimes addressing one issue would cause
us to revise wording covered by an earlier issue. We therefore waited
until all comments had been addressed before responding to commenters.

This message contains the comments you submitted and the resolutions
to your comments. Each comment includes a link to the archived copy of
your original comment on, and may
also include links to the relevant changes in the updated WCAG 2.0
Public Working Draft at

PLEASE REVIEW the decisions  for the following comments and reply to
us by 7 June at to say whether you are
satisfied with the decision taken. Note that this list is publicly

We also welcome your comments on the rest of the updated WCAG 2.0
Public Working Draft by 29 June 2007. We have revised the guidelines
and the accompanying documents substantially. A detailed summary of
issues, revisions, and rationales for changes is at . Please see for more information about the current review.

Thank you,

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

Comment 1:

(Issue ID: LC-752)

Part of Item:
Comment Type: TE
Comment (including rationale for proposed change):

Many proposed edits to definitions, some editorial and some substantive, at

Proposed Change:

Response from Working Group:

Comment 2:

(Issue ID: LC-1489)

advisory[????] – [I believe the that the word is used. If so, needs definition.]

Response from Working Group:

This term is used only in the introduction of the guidelines and while
we also use the term to describe techniques, our use of the term is
not unique to this document. We have made an effort not to include
definitions that are used in their standard, dictionary-defined way.

Comment 3:

(Issue ID: LC-1490)

alternate version
version that provides all of the same information and functionality
and is as up to date as [the] non-conformant content [This definition
is loaded, but may be fine…]

Response from Working Group:

We have incorporated your suggestion to replace "any" with "the" in
the definition of "alternate version."

Comment 4:

(Issue ID: LC-1491)

audio [Add this] What is the difference between audio and audio-only,
or live audio-only

Response from Working Group:

We have made an effort not to include definitions that are used in
their standard, dictionary-defined way and do not feel that our use of
the term "audio" "only" and "live" need additional clarification.
So, per our policy we are not adding them to the glossary.  They are
also further discussed in the  Understanding WCAG 2.0 document.

Comment 5:

(Issue ID: LC-1492)

In standard audio description, narration is added during existing
pauses in dialogue. (See also [Why initial cap?]Extended audio

Response from Working Group:

Thanks for catching. We have fixed the typo.

Comment 6:

(Issue ID: LC-1493)

authored component
an authored unit intended to be used as a part of another authored
unit[What is the relationship between an authored unit and a Web unit?
I really think that this needs to clarified]
authored unit
set of material created as a single body by an author[What really is
this.. unrendered stuff?][I think that since claims are about web
units, that authored units need to bear a clear relationship to web
units… Ideally, the authored unit that is mentioned in this document
would exist within a single web unit… I don't see this going in that
Example 1: a collection consisting of markup, a style sheet, and an
image or audio clip.
Example 2: a set of [one or more than one????!!!!]Web pages intended
to be viewed only as a unit or in sequence.[As opposed to what? I
thought this was the definition of Web unit…..! Priority AAA. This
term needs to be related to Web unit in a more precise way.]
Note: This definition is based on Glossary of Terms for Device Independence.

Response from Working Group:

We have reformulated the success criteria and glossary to remove both
"authored unit" and "authored component" from the guidelines.

Comment 7:

(Issue ID: LC-1494)

baseline (in this document)

[Priority a set of technologies that are used as a basis for
determining conformance to WCAG 2.0. These technologies may include:
markup languages (e.g., XHTML, XML, SMIL, etc.), programming languages
(e.g., …), style sheets (e.g., …), data formats (e.g.,,image formats,
video formats, audio formats, document formats), and APIs.

In defining the baseline, it is valuable to consider, among other
things, the set of technologies that are expected to be supported by,
enabled in user agents by members of the intended audience. [This is
obviously not the only consideration… The original definition leans
too hard on the assumption (expectation) but is not clear about whose
assumption it is…..!]
[Original : "set of technologies assumed to be supported by, and
enabled in, user agents" ]
Note: For more information on baselines and their use, refer to
Technology Assumptions and the "baseline."

Response from Working Group:

The conformance section of WCAG2 has been completely rewritten. The
term "baseline" has been replaced by "accessibility supported Web
technologies". The issue of what it means to be an
accessibility-supported Web technology is addressed in the section
"Accessibility Support of Web Technologies" at .

Comment 8:

(Issue ID: LC-1495)

2. viewport;[Needs definition]

Response from Working Group:

The term "viewport" was taken from the User Agent Accessibility
Guidelines. We have added the definition of viewport to the WCAG2

Comment 9:

(Issue ID: LC-1496)

full multimedia text alternative including any interaction [Is this
what used to be called collated text transcript?]

Response from Working Group:

Yes. We have revised the term to read, "full text alternative for
multimedia including any interaction." based on this and other

Comment 10:

(Issue ID: LC-1497)

information that is conveyed by color [alone?????!]

Response from Working Group:

The success criterion that references this definition requires that
any information conveyed by color is also visually evident without
color. If we added the word 'alone' then the sentence becomes a
catch-22.   if it is also conveyed another way it can't be 'color
alone'.  If this were imperative (e.g. "if conveyed by color alone
then add another way") we could use alone. But not in its current

Comment 11:

(Issue ID: LC-1498)

text, image, or sound that is presented to a user to identify a
component within Web content [Is it simply text that is the critical
piece…. ?]

Response from Working Group:

Yes. This definition now reads:

text, or other component with a text alternative, that is presented to
a user to identify a component within Web content

Comment 12:

(Issue ID: LC-1499)

audio or video synchronized with another type of media and/or with
time-based interactive components[What is meant by another media type.
Does video plus captions count as multimedia? Do you need to refer to
primary content? What are animations? Priority AAA]

Response from Working Group:

We have revised the definition as follows:

   audio or video synchronized with another format for presenting
information and/or with time-based interactive components

By this definition, video plus captions would be considered
multimedia. However, since captions are alternatives for speech and
sounds, it would be unlikely that a video with captions, but without
sound, would be created.

Animations would be multimedia if they were synchronized with another
medium such as audio or with time-based interactive components. If the
animation contains only video information, then it would not be
considered multimedia and would be covered under Guideline 1.1.

Comment 13:

(Issue ID: LC-1500)

natural languages [Note from Eric. The remaining edits were made by
Ruth Loew of ETS. She has a strong background in both linguistics and
sign language]
languages whose rules have evolved through usage within human
communities and which are used by humans to communicate, including
spoken, written, and signed languages

Response from Working Group:

We have changed the term from "natural language" to "human language"
and have updated the definition.

human language

    language that is spoken, written or signed (visually or tactilely)
by humans to communicate with one another

    Note: See also sign language.

Comment 14:

(Issue ID: LC-1501)

rendering of the content and structure in a form that is intended for
perception by the user[Priority AAA. As we know, whether the user can
perceive is greatly affected by factors such as sensory disabilities.]

Response from Working Group:

We have revised the definition to read:

  rendering of the content in a form to be perceived by users

Comment 15:

(Issue ID: LC-1502)

programmatically determined
determined by software from data provided in a user-agent-supported
manner such that the user agents can extract and present this
information to users in different modalities[Some user agents may
present in one and only one modality. Plurality is not an essential
part of the definition][I am not sure I fully understand this concept
of programmatically determined]

Response from Working Group:

The working group felt that the use of "in different modalities" here
is important since it is meant that different user agents and
assistive technologies (whose users may require that information be
presented in different modalities) can access and present the
information. In other words, if information could only be presented in
a single modality, that information could not be programmatically

Comment 16:

(Issue ID: LC-1503)

real-time event
event that a) occurs at the same time as the viewing, b) is not
completely generated by the content[?], and c) is not pre-recorded
[Describe the examples as shown in edits..]
Example 1: A Webcast of a live performance (occurs at the same time as
the viewing).
Example 2: An on-line auction with people bidding (is not prerecorded).
Example 3: Live humans interacting in a fantasy world using avatars
(is not completely generated by the content and occurs at the same
time as the viewing).[Is there a better of example of something that
is only "not completely generated by content."]

Response from Working Group:

We have included the parentheticals almost as proposed. Regarding your
question about examples of things "not completely generated by
content," this phrase is used to exclude situations where the content
itself is designed to react in a predetermined fashion to input.  For
example,  if you click on a picture - it falls from the wall.  This
happens when you click on it but the action is completely determined
by the content and could have a description included.

Comment 17:

(Issue ID: LC-1504)

(revisions to note on "sign language interpretation" definition)
Note: Although some languages have [an artificially created] signed
counterpart, true most sign languages are independent languages that
are unrelated to the spoken language of the same country or culture.

Response from Working Group:

Thank you. We have modified the definition as you proposed.

Comment 18:

(Issue ID: LC-1505)

supplemental content
additional content, which users may use in addition to or instead of
the default content[Is it the case the supplemental content is not an
alternative version or a text alternative? What is the relationship
between supplemental content and text alternatives?????], that
illustrates or clarifies the default content
Example: Examples of supplemental content may include text, images and audio.
[Do we nNeed a definition of Default Content?
Do URIs for the supplemental content need to be supplied within the claim?
Does supplemental content need to be an explicit part of the scope?]

Response from Working Group:

Thank you for pointing out the overlap between these two terms. We
have revised the definition to read, "additional content that
illustrates or clarifies the primary content" and have added a series
of examples to help clarify the issue. We have also modified the
success criterion to allow for both supplemental content and
alternative versions.

Comment 19:

(Issue ID: LC-1506)

test or exercise that must use a particular sense
test or exercise where the content must be presented in a particular
sensory format
Example: Color blindness test, hearing test, vision exercise, spelling test

[Not sure if it is possible to improve on this….However, there is a
wider range of situations, where providing alternate content could
undermine the validity of the result of the effectiveness of the
application. The conflict may or may not be "sensory" in nature. For
example, the issue may be cognitive/linguistic, etc. It may be worth
trying to fine tune this issue more for this document.].

Response from Working Group:

We have updated this term and its definition as follows:

must be presented in non-text format:
   would be invalid if presented in text

Example: Color blindness test, hearing test, vision exercise, spelling test

Comment 20:

(Issue ID: LC-1507)

text alternative
programmatically determined text that is used in place of non-text
content, or text that is used in addition to non-text content and
referred to from the programmatically determined text. [It seems that
there should be a clearer way to say this… Or perhaps better, give a
couple of examples.. This is so fundamental, one wants it to be
absolutely clear.]
Relation to non-text content Referred to from
1. Used in place of 1. [Is this information missing from def?]
2. Used in addition to 2. programmatically determined text

Response from Working Group:

We have included an example to make this clear.

Example: An image of a chart is described in text in the paragraph
after the chart. The short text-alternative for the chart indicates
that a description follows.

Comment 21:

(Issue ID: LC-1508)

used in an unusual restricted way
words used in such a way that users must know exactly what definition
to apply in order to understand the content correctly
Example: The word "representational" means something quite different
if it occurs in a discussion of visual art as opposed to a treatise on
government[Very obscure example… Could there be a simpler example?],
but the appropriate definition can be determined from context. By
contrast, the word "text" is used in a very specific way in WCAG 2.0,
so a definition is supplied in the glossary.[Maybe just say that many
of the words in the glossary may be described this way.]

Response from Working Group:

We have simplified the example per your request, but have kept the
reference to "text" because it is a good example of how we are using
it in a restricted way.

Comment 22:

(Issue ID: LC-1509)

user-agent-supported [Priority AA]
implemented by user agents and assistive technologies[Are not ATs also
user agents? See previous glossary entry]
Note: One of the factors that should be considered before adding a
technology to a baseline is the availability of affordable user
agentsand assistive technologies which support the technology.

Response from Working Group:

We removed the term "user-agent-supported" from the definition of
programmatically determined, so it no longer occurs in the glossary.

The definition of "programmatically determined" now reads "determined
by software from author-supplied data provided in a way that different
 user agents, including assistive technologies, can extract and
present this information to users in different modalities".

Comment 23:

(Issue ID: LC-1510)

Web unit


a collection of information identifiable by a single Uniform Resource
Identifier (such as a URL) that consists of one or more resources and
that is intended to be rendered together.

• Example1: A Web page and embedded media
• Example 2: An interactive or immersive environment addressable via a
single URI.

[OLD version with comments:
"a collection of information, consisting of one or more resources,
intended to be rendered together[By together, this may be
simultaneous, or sequentially???], and identified by a single Uniform
Resource Identifier (such as a URLs[Should both be singular, right?])
[Priority AAAA. I'd like to get greater clarity on this…..]
Note: This definition is based on the definition of Web page in Web
Characterization Terminology & Definitions Sheet. The concept of
simultaneity was removed to allow the term to cover interactive and
scripted content.
Example 1: An interactive movie-like shopping environment accessed
through a single URI, where the user navigates about and activates
products to have them demonstrated, and moves them to a cart to buy
them.[I thought that the shopping was considered a "process"…]
Example 2: A Web page including all embedded images and media.
[The notion of web unit is key in this document. Any characterization
that is not explicitly tied into the notion of web unit has no
normative force…! This included authored unit, authored component,
content, supplemental content, etc.!] ]

Response from Working Group:

We have modified the term "Web unit" to be "Web page" and have updated
the definition. Because this term is used in multiple W3C specs, we
can not make revisions to the definition that would make it
inconsistent. We have, however, incorporated your suggestions in the
examples of the definition of "Web page" at .

Web page

a resource that is referenced by a URI and is not embedded in another
resource, plus any other resources that are used in the rendering or
intended to be rendered together with it

    Note: Although any "other resources" would be rendered together
with the primary resource, they would not necessarily be rendered
simultaneously with each other.

    Example 1: When you enter in your
browser you enter a movie-like interactive shopping environment where
you visually move about a store dragging products off of the shelves
around you into a visual shopping cart in front of you. Clicking on a
product causes it to be demonstrated with a specification sheet
floating alongside.

    Example 2: A Web resource including all embedded images and media.

    Example 3: A Web mail program built using Asynchronous JavaScript
and XML (AJAX). The program lives entirely at,
but includes an inbox, a contacts area and a calendar. Links or
buttons are provided that cause the the inbox, contacts, or calendar
to display, but do not change the URL of the page as a whole.

    Example 4: A customizable portal site, where users can choose
content to display from a set of different content modules.

Comment 24:

(Issue ID: LC-1511)

Wisconsin Computer Equivalence Algorithm for Flash Pattern Analysis (FPA)
a method developed at the University of Wisconsin, working in
conjunction with Dr. Graham Harding and Cambridge Research Associates,
for applying the United Kingdom's "Ofcom Guidance Note on Flashing
Images and Regular Patterns in Television (Re-issued as Ofcom Notes 25
July 2005)" to content displayed on a computer screen, such as Web
pages and other computer content[What is intended benefit?]

Response from Working Group:

Because the algorithm developed by Dr. Harding was based on average
viewing distances from television sets, this work needed to be adapted
to match viewing distances and screen sizes for computer screens.
Additional information about the benefits is available in
Understanding Guideline 2.3.

Received on Thursday, 17 May 2007 23:33:38 UTC