May 1, 2003 Proposed Reorganization
Note: Items in square brackets indicate success criteria numbering in the April 29 Draft.
Guideline 1 PERCEIVABLE.
Make Content Perceivable
Group One Checkpoints – Minimum
1-M1 [1.1] All non-text content that can be expressed in words has a text
equivalent of the function or information that the non-text content was intended
to convey.
Success Criteria – Required
- non-text content that can be expressed in words has a text-equivalent
explicitly associated with it.
- non-text content that can not be expressed in words has a descriptive
label provided as its text-equivalent.
- The text equivalent should fulfill the same function as the author
intended for the non-text content (i.e. it presents all of the
intended information and/or achieves the same function of the
non-text content).
Recommended
- the text-equivalent has been
reviewed and is believed to fulfill the same function as the author
intended for the non-text content (i.e. it presents all of the intended
information and/or achieves the same function of the non-text
content)
1-M2 [1.2] Synchronized media equivalents are provided for time-dependent
presentations.
Success Criteria – Required
- an audio description is provided of all significant visual information in scenes, actions and events that cannot be perceived from the sound track alone.
- Note: When adding audio description to existing materials, the amount of information conveyed through audio description is constrained by the amount of space available in the existing audio track. It may also be impossible or inappropriate to freeze the audio/visual program to insert additional audio description.
- all significant dialogue and sounds are captioned
exception: if the Web content is real-time and audio-only and not time-sensitive and not interactive a transcript or other non-audio equivalent is sufficient.
- descriptions and captions are synchronized with the events they represent.
-
if the Web content is real-time video
with audio, real-time captions are provided unless the content:
-
is a music program that is primarily non-vocal
-
If the Web content is real-time non-interactive video (e.g., a Webcam of ambient conditions), either provide an equivalent that conforms to checkpoint 1.1 (e.g., an ongoing update of weather conditions) or link to an equivalent that conforms to checkpoint 1.1 (e.g., a link to a weather Web site).
- if a pure audio or pure video presentation requires a user to respond interactively at specific times in the presentation, then a time-synchronized equivalent (audio, visual or text) presentation is provided.
exception:
if content is rebroadcast from another medium or resource that complies to broadcast requirements for accessibility (independent of these guidelines), the rebroadcast satisfies the checkpoint if it complies with the other guidelines.
Recommended
- the audio description has been reviewed and is believed to include all significant visual information in scenes, actions and events (that can't be perceived from the sound track) to the extent possible given the constraints posed by the existing audio track (and constraints on freezing the audio/visual program to insert additional auditory description).
Listed below are items from group two which relate to this checkpoint:
- a text document that merges all audio descriptions and captions into a collated script (that provides dialog, important sounds and important visual information in a single text document) is provided.
- captions and audio descriptions are provided for all live broadcasts
which provide the same information.
- The presentation does not require the user to read captions and the visual presentation simultaneously in order to understand the content.
1-M3 [1.3] All content and structure are [separate or separable from]
available independently of presentation.
Success Criteria – Required
- the following can be derived programmatically (i.e. through assistive
technology compatible markup or data model) from the content without interpreting
presentation.
- any hierarchical elements and relationships, such as headings, paragraphs
and lists
- any non-hierarchical relationships between elements such as cross-references
and linkages, associations between labels and controls, associations
between cells and their headers, etc.
- any emphasis
[An example for color coding and an example of forms and labels should be
added to the informative information here.]
1-M4 [1.6] All characters and words in the content can be unambiguously
decoded.
Success Criteria – Required
- text in the content is provided in Unicode or sufficient information is
provided so that it will be automatically mapped back to Unicode.
Note: If a standard format for doing it can be achieved, we might require
that linkages to glossaries for all abbreviations and acronyms that are created
by the author or site be provided. We could also recommend that linkages
to any abbreviations, acronyms, etc. used by the authors also be provided.
We could also have a weaker recommendation for acronyms and abbreviations
appearing on the site that linkages to glossaries explaining all abbreviations
acronyms, etc. that appear in any documents on the site be provided.
Recommended
- abbreviations and acronyms are clearly identified where they occur. (See
also checkpoint 4.3.)
- symbols such as diacritic marks that are found in standard usage of the
natural language of the content, and necessary for unambiguous interpretation
of words, are present or another standard mechanism for disambiguation is
provided.
Group Two Checkpoints
1-E1 [1.4] Structure has been made perceivable to more people through
presentation(s), positioning, and labels.
Success Criteria – Required
- the structural elements present have a different visual appearance or
auditory characteristic than the other structural elements.
Recommended
- the structural emphases are chosen to be distinct for different major
display types (e.g. black and white, small display, mono audio
playback).
- content is constructed such that users can control the presentation of
the structural elements.
- alternate presentation formats are available to vary the emphasis of
the structure.
1-E2 [1.5] Foreground content is easily differentiable from background
for both auditory and visual presentations [required].
Success Criteria – Required
- text content that is presented over a background image or pattern is
implemented using mechanisms that allow the user to display the text without the background image or pattern.
Recommended [All level 2 and 3 items from checkpoint 1.5.]
- when text content is presented over a background image or pattern, the
text is easily readable when the page is viewed in 256 grayscale.
- text content is not presented over a background image or pattern OR the
text is easily readable when the page is viewed in black and white (no grayscale).
- audio content does not contain background sounds OR the background sounds
are at least 20 db lower than the foreground audio content.
- text content is not presented over a background image or color OR the
colors used for the text and background or background image pass the following
test:
- no tests/algorithms are available at this time
Reviewer's Note: The working group is
seeking an algorithm that measures contrast in a way that is accurate
and testable enough that we could include it in the guidelines. One algorithm,
which comes from the Techniques For
Accessibility Evaluation And Repair Tools document, is currently under
consideration for inclusion in the techniques, but the group has not yet
found something that is specific enough to be included at the guidelines
level.
Guideline 2 OPERABLE.
Ensure that Interface Elements in the Content are Operable by Any User
Group One Checkpoints – Minimum
2-M1 [2.1] Ensure that all of the functionality is operable at a minimum
through a keyboard or a keyboard interface.
Success Criteria – Required
- all of the functionality of the content where the functionality or
its outcome can be expressed concisely in words is operable at a minimum
through a keyboard or keyboard interface.
-
Note: refer to checkpoint 5.3 for information
regarding user agent support.
Recommended
- wherever a choice between event handlers is available and supported,
the more abstract event is used.
[Informative information. Add a definition of operable as meaning not using
mouse keys or an infinite tabbing on a long doc or other unreasonably inefficient
keyboard access. Add another definition that says something to the effect
that access is efficient. That is, mouse keys can’t be used as a way to provide
access via keyboard and if a document has a very large number of links, some
mechanism other than tabbing through them one at a time needs to be provided]
2-M2 [2.2] Allow users to control any time limits on their reading, interaction,
or responses unless control is not possible due to nature of real time events
or competition.
Success Criteria – Required
- at least one of the following is true for each time limit:
- the user is allowed to deactivate the time limits,
- or the user is allowed to adjust the time limit over a wide range
which is at least 10 times the average user's preference,
- or the user is warned before time expires and given at least 10
seconds to extend the time limit,
- or the time limit is due to a real-time event (e.g. auction) and no
alternative to the time limit is possible,
- or the time limit is part of a competitive activity where timing is
an essential part of the activity (e.g. competitive gaming or time
based testing).
Related group two items -- It is recommended , but not required
that, wherever possible, activities be designed so that time limits are not
an essential part of the activity. (e.g. alternate forms of competition,
testing, etc. that are not time based.)
Group Two Checkpoints
2-E1 [2.3] User can prevent screen flicker.
Success Criteria – Required
- At least one of the following is true:
- content was not designed to flicker (or flash) in the range of 3 to
49 Hz.
-
Reviewer's Note: We would
like to include a criteria here which would state that a test that
was conducted and the pages passed. No test or tool exists yet
though. We're looking into how such a test and/or tool might be
designed.
- if flicker is unavoidable, the user is warned of the flicker before
they go to the page, and as close a version of the content as is
possible without flicker is provided.
Recommended
- animation or other content does
not visibly or purposely flicker between 3 and 49 Hz.
- content that might create a
problem has been tested [using XYZ tool]; only pages with unavoidable
flicker remain and appropriate warnings along with a close alternative
presentation have been provided for these pages.
- (tougher test - that would make pages pass with even slower equip.
Equip might be old or just slow for other reasons)
Note: Because this checkpoint impacts on and limits types of presentation,
it is not included in group one. However, it is very strongly recommended
that anyone creating accessibility guidelines or regulations consider
this checkpoint for their required set.
2-E2 [3.1 and 3.2] Structure and/or alternate navigation mechanisms have
been added to facilitate orientation and movement in content.
Success Criteria – Required In documents greater than 50,000 words
or sites larger than 50 perceived pages, the following are provided.
- Additional hierarchical structure mark up
-
Table of contents (or site map)
- Alternate display orders (or alternate site navigation mechanisms)
-
(Items currently listed under Success Criteria for
3.1 and 3.2 should be considered for here, but many/most of them should
actually be moved to the techniques document???)
Note: One of the reasons for combining these two is that they both
get at the same issue. Also, on many sites, it is becoming increasingly difficult
to tell when you are navigating within a site and when you are navigating
within a document. This will only increase over time. Since the title of
this thing is web content, it is recommended that these two
items be combined so that we are talking about web content versus separating
content from sites.
2-E3 [3.5] Methods are provided to minimize error and provide graceful
recovery.
Success Criteria – Required
- if an error is detected, feedback is provided to the user identifying
the error.
Recommended
- the content has been reviewed
and is believed to have incorporated error prevention and recovery
methods that are considered to be effective and appropriate
- where possible, the user is allowed to select from a list of options as
well as to generate input text directly
- errors are identified specifically and suggestions for correction are
provided where possible
- checks for misspelled words are applied and correct spellings are
suggested when text entry is required.
- where consequences are significant and time-response is not important,
one of the following is true
- actions are reversible where possible
- where not reversible, actions are checked for errors in
advance.
- where not reversible, and not checkable, a confirmation is asked
before acceptance
Guideline 3 UNDERSTANDABLE.
Make it as easy as possible to understand the content and controls
Group One Checkpoints
3-M1 [1.6 partial] Language of content can be unambiguously determined.
Success Criteria – Required
- passages or fragments of text occurring within the content that are written
in a language other than the primary natural language of the content as
a whole, are identified, including specification of the language of the
passage or fragment.
- the primary natural language of the content is identified at the page
level.
Changes in the language within a document are marked.
Recommended If the document as a whole is written in one language,
a tool can generally determine the language. If there is a document on a
site which is mostly all in one language, then the single document in one
language could be indicated.
3-M2 [4.3] The meaning of words, abbreviations, and acronyms can be unambiguously
determined.
Success Criteria – Required
- acronyms and abbreviations are defined the first time they appear.
Recommended [All items from level 2 of 4.3 plus “cascading dictionaries”]
- @@ "cascading dictionaries"
- the content has been reviewed, taking into account the additional
ideas listed below, and it is believed that complex, abbreviated or
unfamiliar information has been annotated appropriately
- provide a definition or link (with the first occurrence) of phrases,
words, acronyms, and abbreviations specific to a particular
community.
- provide a summary for relationships that may not be obvious from
analyzing the structure of a table but that may be apparent in a visual
rendering of the table.
- if contracted forms of words are used such that they are ambiguous,
provide semantic markup to make words unique and interpretable.
Group Two Checkpoints
3-E1 [4.1 and 4.2] Content is written to be no more complex than is necessary
and/or supplement with simpler forms of the content.
Success Criteria – Required
- familiarity of terms and language structure
- reasonableness of length and complexity of sentences
- coherence of paragraphs (and sensibility in length)
- clarity of headings and linked text when read out of context
- accuracy and uniqueness of page titles
- care in the use of all-capital letters where normal sentence case might
increase comprehension
- authors have included non-text content to supplement text for key pages
or sections of the site where they felt it was appropriate.
Recommended
- use of sentence structures that increase understanding
- such as active voice in languages where this form helps convey information
- length of noun phrases
- strings of no more than three or four nouns are easiest to understand
- clarity of reference with pronouns and anaphoric expressions (these refer
back to something already said in the text)
- example of potential ambiguity: "Scientists study monkeys. They eat
bananas."
- correct use of conjunction forms and adverbs to make explicit the relationship
between phrases or parts of the text
- such as "and," "but," "furthermore," "not only"
- complexity of verb tenses
- do the tenses used in a document seem overly complicated?
- intelligibility of verb phrases
- familiarity of idioms or slang
- logic in the order and flow of information
- consequences of ambiguity or abstraction
- improved readability of vertical lists might offer in place of long paragraphs
of information
- use of summaries to aid understanding
- thoroughness in the explanation of instructions or required actions
- consistency in the use of names and labels
- clarity where the document:
- addresses users
- explains choices and options
- labels options to get more information
- instructs users how to modify selections in critical functions (such
as how to delete an item from a shopping cart)
- application of:
- proper markup to highlight key information
- goal-action structure for menu prompts
- default settings (and the ease in re-establishing them)
- two-step "select and confirm" processes to reduce accidental selections
for critical functions
- calculation assistance to reduce the need to calculate
- at least one of the following is true:
- new material is tested with potential users for ease of accessibility
- a controlled language is used
- support is given for conversion into symbolic languages
- the content has been reviewed and it is believed that text has been supplemented with non-text content to the
extent deemed appropriate by the author
- non-text content has
been added to the site for key pages or sections specifically to make the
site more understandable by users who cannot understand the text only
version of the site.
3-E2 [3.3 and 3.4] Layout and behavior of content is consistent but not
identical.
Success Criteria – Required
- key orientation and navigational elements are generally found in one or
two locations or their locations are otherwise predictable.
- where inconsistent or unpredictable responses are essential to the
function of the content (e.g. mystery games, adventure games, tests,
etc.) the user is warned in advance of encountering them.
- wherever there are extreme changes in context, one of the following is
true:
- an easy to find setting, that persists for the site visit, is
provided for the user to deactivate processes or features that cause
extreme changes in context or
- extreme changes in context are identified before they occur so the
user can determine if they wish to proceed or so they can be prepared
for the change
Recommended
- the content has been reviewed, taking into account the
additional ideas listed below, and it has been concluded
that key
orientation and navigational
elements are generally found in one or two locations, or their locations
are otherwise predictable
- the content has been reviewed, and it has been found that where
inconsistent or unpredictable responses
are essential to its function (e.g. mystery games,
adventure games, tests, etc.), the user is warned in advance of
encountering them
Guideline 4 ROBUST.
Use web technologies that maximize the ability of the content to work with
current and future accessibility technologies and user agents.
Group One Checkpoints
4-M1 [5.1] Technologies are used according to specification
Success Criteria – Required
- for markup, except where the site has documented that a specification
was violated for backward compatibility, the markup has passed validity
tests of the language (whether it be conforming to a schema, Document
Type Definition (DTD), or other tests described in the specification),
structural elements and attributes are used as defined in the
specification, accessibility features are used, and deprecated features
are avoided.
Reviewer's Note:The following two success criteria seem to overlap with checkpoint 5.4. There is an open question about whether they should be deleted since Checkpoint 5.4 covers programmatic interfaces.
- for Application Programming Interfaces (API's), programming standards
for the language are followed.
- accessibility features and API's are used when available.
Recommended
- for markup, the markup has passed validity tests of the language (whether
it be conforming to a schema, Document Type Definition (DTD), or other tests
described in the specification), structural elements and attributes are
used as defined in the specification, accessibility features are used, and
deprecated features are avoided.
4-M2 [5.2] Ensure that technologies relied upon by the content are declared
and widely available.
Success Criteria – Required
- a list of technologies and features, support for which is required in order
for the content to be operable, has been determined and is
documented in metadata and / or a policy statement associated with
the content.
-
Note: When determining your
list of technological requirements, consider that assistive hardware and software is often
slow to adapt to technological advances, and the availability of
assistive technology varies across natural languages. Verify that
assistive technology compatible with the technologies you choose is
available in the natural language(s) of your content.
- the content is still usable when features not on the
required list (for
example, scripting and stylesheets) are turned off or not supported.
Recommendation
- Technologies and features on the required list are
available in at least two independently-developed implementations.
- of at least two such implementations, it is true that the
technologies and features on the required list have been
supported by at least one prior version of the software.
[In the definitions add a definition of “widely available” to include something
which is low cost and available in many?/most? countries/languages.]
4-M3 [5.3 and 5.4] Technologies used for presentation and user interface
support accessibility or alternate versions of the content are provided which
do support accessibility.
Success Criteria - Required
- the technology or combination of technologies chosen:
- support device independence
- include accessibility features
- have publicly documented interfaces for interoperability
- make use of operating system accessibility features (either
directly or via the user agent) supported by assistive technologies
in the natural language(s) of the content
- are implemented in user agents and/or proxies in the natural
language(s) of the content
- any applications with custom user interfaces conform to at least Level
A of the User Agent Accessibility
Guidelines 1.0. If the application cannot be made accessible, an
alternative, accessible solution is provided.
[Note: Many of the items listed in 5.3 are ambiguous and/or not actually
required for accessibility. We should carefully examine this one. For example:
-
What does device independence mean besides the items that are already
required in these guidelines?
- What does “include accessibility features” mean besides what is included
in this set of guidelines?
- Having interfaces for interoperability publicly documented simply means
that they have been posted on a website, it doesn’t necessarily mean that
it follows any standards or that anybody supports it and it doesn’t necessarily
make something accessible to anyone.
-
Unless these operating system features are all listed specifically in
this standard, they should not be at a “required” level in the standard.
Cynthia
has re-written this section and we should look at her recommendations
carefully. These notes are based off our current post it draft.
Recommended
- the interface has been tested using a variety of assistive technologies
and preferably real people with disabilities who use assistive
technologies to determine that assistive technologies can access all
information on the page or hidden within the page.
Reviewer's Note: It would be possible to comply with the
checkpoint without carrying out tests (either with users or with
assistive technologies). Conversely, it is possible to conduct tests, but
still fail to meet the checkpoint (with respect to assistive technologies
that were not tested, for example). Should this success criterion be
deleted?
- device-independent access to functionality is provided
- accessibility conventions of the markup or programming language (API's
or specific markup) are used
Group Two Checkpoints
[NONE]