Draft Reformulation of Web Content Accessibility Guidelines
W3C Working Draft 23 August 2000
- This version:
- http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-20000823
- Latest version:
- http://www.w3.org/WAI/GL/WCAG20
- Preview version:
- http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-20000815
- Editors:
- Jason White, University of Melbourne
Wendy Chisholm, W3C
Gregg Vanderheiden, Trace R&D Center
Status
This document is prepared by the W3C
Web Content Accessibility Guidelines Working Group (WCAG WG) to show how
more generalized (less HTML-specific) WCAG checkpoints might
read. This draft is not based on consensus of the working group nor
has it gone through W3C process thus it in no way supersedes the checkpoints
in WCAG 1.0. This draft derived from the following materials:
Based on feedback about the application of WCAG 1.0 to emerging XML
applications and other Web trends the WCAG WG wants to investigate how more
generalized checkpoints might read. Therefore, this draft has been
produced.
This is a draft document and may be updated, replaced, or obsoleted by
other documents at any time. It is inappropriate to use W3C Working Drafts as
reference material or to cite them as other than "work in progress". A list of
current W3C Recommendations and other technical documents can be found at http://www.w3.org/TR/.
Please send comments on this document to w3c-wai-gl@w3.org. The archives for this
list are publicly available.
Introduction
The following new terminology is proposed in this draft:
- 1: Principles
- Principles are the most fundamental strategies for ensuring
that content is accessible for individuals with a variety of
constraints. They correspond to what are called "Guidelines" in WCAG 1.0.
- 2: Guidelines
- Guidelines are more detailed than Principles.
However, Guidelines do not provide technology-specific guidance
(see the definition for Checkpoints). Some Guidelines
may apply only to a certain range of technologies, such as Guideline XX
which only applies to YY. Guidelines in this document may
sometimes correspond to Checkpoints in WCAG1.0 as some of those
checkpoints are not technology-specific.
- 3: Checkpoints [not shown in this draft]
- Checkpoints are strategies for making accessible Web content
using a specific technology or combination of technologies. The lists
of Checkpoints are not an exhaustive lists of all possible
accessible strategies for all technologies and combinations of
technologies. Therefore, to conform to WCAG 2.0 the Guidelines
must be met, but they are met by implementing the technology-specific
Checkpoints. Checkpoints in this document may
sometimes correspond to Checkpoints in WCAG 1.0 as some of
those checkpoints are technology-specific.
Principles and Guidelines
Principle 1: All information must be available entirely through visual,
auditory, or tactile methods or in any combination required by the user.
Users must be able to access information entirely through sight, entirely
through sound, entirely through touch, or any combination thereof.
Provide access to information through each of the senses alone or any
combination required by the user.
Guidelines
- 1.1 Provide a textual equivalent for every non-text (auditory or
graphical) component or multimedia presentation.
- 1.2 Provide an auditory description of the important information of the
visual track of a multimedia presentation.
- 1.3 For any time-based multimedia presentation (e.g., a
movie or animation), synchronize equivalent alternatives
(e.g., captions or auditory descriptions of the visual track)
with the presentation. [@@currently being rewritten in regards to wcag
1.0. see how that turns out.]
Principle 2: Capture structure and implied meaning (semantics) in markup
or in a data model.
User agents and/or assistive technologies must have access to the structure
of information as well as implied information. Content and structure must be
available separately from the presentation. Oftentimes, presentation carries
additional information that needs to be expressed explicitly in the data in
some way.
Guidelines
- 2.1 Use markup languages and data models properly and in accordance with
specification. For example, ensure that XHTML content validates to the
XHTML specification.
- 2.2 Use style languages, where available, to control layout and
presentation. For example, use CSS with HTML and XSL with XML derivatives
such as MathML.
- 2.3 Where presentation is used to communicate distinctions of meaning or
structure within the content, ensure that the meaning is captured in the
markup. Note that the semantic and presentational
markup corresponding to a document need not reside in the same file or
logical resource; these guidelines mandate only that both must exist and
be available to the user agent. For example, if the XHTML "class"
attribute is used in conjuction with CSS to create sidebars, use
namespaces to attach the meaning "sidebar" to that class.
- 2.4 Do not rely on presentation alone to express semantic distinctions
(this is a corollary of the preceding guideline). For example, do not
rely on color alone to indicate which items in a list are "new" and which
are "old."
- 2.5 Ensure that distinctions needed to the render the content
auditorally or tactiely are captured in the markup. For example, use
markup to identify changes in the natural language of a document, or to
distinguish fragments of mathematical notation or computer program code
from the surrounding text.
Principle 3: Design for ease of comprehension, browsing and
navigation
Guidelines
- 3.1 Use a consistent style of presentation. The presentation should
reflect the structure and meaning to make it easier to understand. For
example, all top level headings should be the same color, font, font size,
and positioned at or near the same place sitewide.
- 3.2 Provide clear and consistent navigation mechanisms throughout a web
site.
- 3.3 Supply an overview of highly structured material. For example,
provide a site map of the general organization of a site, or a table of
contents for a document split into multiple chapters, or a summary of a
table of a city's budget data.
- 3.4 Divide large blocks of information into groups where natural and
appropriate. This includes the use of headings, labels, and title to
identify structural divisions within the content.
- 3.5 If search functions are provided, enable different types of searches
for different skill levels and preferences.
- 3.6 Place distinguishing information at the beginning of headings,
paragraphs, lists, etc. unless linearizing a data table. For example, in
list of departments put the word "department" following the title of the
department as in, "Shoe Department, Toy Department, Housewares Department"
rather than "Department: Shoes, Department Toys, etc." However, if
linearizing a data table it might be helpful to put the row or column
heading before the information from each data cell.
- 3.7 Use the clearest and simplest language appropriate for a site's
content.
- 3.8 Supplement text with graphic or auditory presentations where they
will facilitate comprehension of the content.
- 3.9 Define key terms, and provide expansions for abbreviations and
acronyms, which should be identified using appropriate markup.
Principle 4: Design user interfaces for device independence
Guidelines
These need to be reworked to take account of the separation between user
interface logic and presentation which is provided by X-Forms. [Do
they??]
- 4.1 Specify one or more default presentations of the content.
Where possible, offer a variety of alternative presentations suited to
different output devices. For example, provide style sheets relevant to
high and low-resolution displays, printers and speech output systems. Or
supply pre-formatted versions to be selected via content negotiation or
explicit user requests.
- 4.2 Associate an explicit label with each user interface control.
- 4.3 Ensure that user interface controls are grouped logically.
- 4.4 Ensure that event handlers are device-independent. [@@covers too
much. refer to UAAG?]
- 4.5 Design user interfaces to be compatible with assistive
technologies.
- 4.6 Ensure that foreground and background color combinations provide
sufficient contrast when viewed by someone having color deficits or when
viewed on a black and white screen.
Principle 5: Compensate for older technologies and missing or incompletely
implemented features of user agents
Guidelines
- 5.1 Make sure that the use of newer technologies transform gracefully
when a browser does not support the technology or the technology is not
enabled in the user's configuration.
- 5.2 Avoid causing content to blink or flicker in the range 4 to 59
flashes per second (Hertz) range with a peak sensitivity at 20 flashes per
second as well as quick changes from dark to light (like strobe lights).
[@@What about user agents that can stop pause or stop
flicker?]
- 5.3 Avoid causing pages to be refreshed or updated automatically.
[@needs work. can't be absolute.]
Any other interim measures which are considered to be of vital importance
may be included here.
Glossary
@@need definitions
- Content
- Equivalent
- Markup
- Presentation
- Semantics
$Date: 2000/11/08 08:27:40 $