This document describes techniques that Web accessibility validation tools
may use to evaluate the conformance of HTML documents to the Web Content Accessibility
Guidelines 1.0 (WCAG 1.0). This document also describes techniques that
Web authoring tools may use to help authors modify HTML documents to conform
to WCAG 1.0. We anticipate that tool developers may develop accessibility
validation and/or repair modules to be incorporated into commercial authoring
tools, validation tools, and perhaps user agents.
This section describes the status of this document at the time of its
publication. Other documents may supersede this document. The latest status of
this document series is maintained at the W3C.
feedback on existing techniques discussed in this document,
suggestions for new techniques,
implementation and testing of the techniques discussed in this
document.
The working group expects to collect and test new and existing techniques
in the next few months. The document will be updated to reflect the group's
findings.
Information about existing Evaluation, Repair, and Transformation Tools for
Web Content Accessibility is available from the working group's home page.
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/.
The Web Accessibility Initiative (WAI) has produced a foundation document,
The W3C Web Content
Accessibility Guidelines (WCAG 1.0), that describes what must be done to
make a Web page accessible to all. Tools are needed to help authors determine
if a web site is accessible to everyone and to help repair it if it is
not.
This document builds on the WCAG 1.0 foundation by outlining techniques
that evaluation and repair tools may use to uncover accessibility problems and
possibly repair them. These techniques may be used by those who create web
authoring tools or by anyone interested in creating accessible Web
documents.
It is important that people with disabilities are included in the "anyone
interested in creating accessible Web content." Creating accessible Web
content is as important as accessing Web content. Therefore, evaluation and
repair tools themselves need to be accessible to people with disabilities.
However, this document does not describe how to make the user interface
accessible. Please refer to the User
Agent Accessibility Guidelines for information on making the user
interface accessible.
Many people using evaluation and repair tools may be new to the Web and
will not be familiar with the various markup languages that are used. Many
others will not know about Web accessibility. Tools should be intuitive and
easy to use and available at a minimal cost. Tools should not generate
excessive warnings or false positive accessibility errors.
Some of the web-content accessibility checkpoints cannot be checked
successfully by software algorithms alone. There will still be a dependence on
the user's ability to exercise human judgment to determine conformance to the
guidelines. It is imperative that any tool have features that assist in
reminding, without nagging; in helping, without demeaning; in suggesting,
without demanding. We hope that the techniques in this document, implemented
in software programs, will gently guide authors along the path to more
accessible documents.
This document is based on The W3C Web Content Accessibility
Guidelines. It lists each guideline and checkpoint in in that document.
Under each checkpoint it lists one or more techniques for evaluating and, in
some cases, repair. �Each technique comprises the following subsections:
Open issues for this technique
This section lists open issues and questions about a particular
technique. �
Evaluation:
The algorithmic and heuristic tests that will be applied. consisting
of
Elements - the elements to which this test
applies, e.g. IMG etc. If it only applies to an element
of a particular type, this is noted (e.g. INPUT
�TYPE="image">
Requirements - the conditions which will be
tested for by means of algorithms and heuristics.
Note: in a few cases, the warning is always presented.
Suggested message:
Messages displayed to the author if the element is found and the
requirement is not satisfied.
Suggested repair:
Actions that may be required to repair the accessibility problem.
Test files:
Used to test evaluation tools to see if they find the accessibility
problem. These are under construction!!
Discussion files:
Discussion and comments on the technique.
Note. This document specifies only the function of
evaluation and repair tools. Nothing in this document should be taken to imply
a particular user interface.
Guideline 1. Provide equivalent
alternatives to auditory and visual content.
Checkpoint 1.1 - Provide a text
equivalent for every non-text element
Checkpoint 1.2 - Provide redundant
text links for each active region of a server-side image map
Checkpoint 1.3 - Until user agents
can automatically read aloud the text equivalent of a visual track,
provide an auditory description of the important information of the visual
track of a multimedia presentation
Checkpoint 1.4 - 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
Checkpoint 1.5 - Until user agents render
text equivalents for client-side image map links, provide redundant text
links for each active region of a client-side image map
Suspicious - "alt" attribute value is longer than 150
characters. Suggest that a description file be created.
Suggested message:
Missing text equivalent: Missing text equivalent for image.
Suspicious "alt" attribute: Suspicious text equivalent for
image: [current "alt" text] - [could be file size | could be
file name | could be placeholder text | text equivalent should be short,
perhaps this could be a "longdesc"].
Invalid "alt" attribute: Invalid text equivalent for image:
[text equivalents can not be empty].
Suggested repair:
Prompt the user for a text equivalent for the image.
If the document contains another instance of the image and that image
contains an "alt" attribute, suggest that "alt"
attribute value.
After user has entered an "alt" attribute for the image,
check the site for other instances of the image. If the site contains
other images that are the same and they do not have a text equivalent,
suggest that all same images without an "alt" attribute use
the new "alt" attribute value.
Valid "longdesc" attribute or a d-link required if
describing the image will add information not given in the text of the
page. The amount of information in the image and the context in which
it is used will determine how detailed the description should be.
Note: d-link now deprecated.
If describing the image will add information not given in the text of
the page, you need to provide a description of the image. The amount of
information in the image and the context in which it is used will
determine how detailed the description should be.
Ask user if the image presents information that is not included in the
page or in the text equivalent for the image. Allow the user to create or
associate a description.
with the "longdesc" attribute on an IMG
element
via a D-link
If another document on the same site uses the same image and has a
"longdesc", suggest that "longdesc" file.
Missing text equivalent: Missing text equivalent for this button.
Suspicious text equivalent: Suspicious text equivalent for button:
[current "alt" attribute] - [could be file size | could be
file name | could be placeholder text].
Invalid text equivalent: Invalid text equivalent for button: [
"alt" attribute can not be empty | text equivalent can not
contain only 'spaces'].
Missing text equivalent: Applet must have valid a valid
"alt" attribute or accessible HTML content."
Suspicious text equivalent: Suspicious text equivalent for applet:
[current "alt" attribute value] - [could be file size | could
be image file name | could be placeholder text | could be applet
executable name].
Invalid text equivalent: Invalid "alt" attribute for applet
- [text equivalent can not be empty | text equivalent can not be all
'spaces'].
Missing alternative representation: Missing alternative representation
for this object.
Suspicious alternative representation: Suspicious alternative
representation for this object: [current alternative representation] -
[could be placeholder text]
If the site contains a document that contains the same object and that
object contains a valid alternative representation, suggest that
alternative representation.
Requirement: Valid "longdesc" attribute (refer to
checkpoint 12.1 for information about titling frames).
If a FRAMESET has three or more frames and at least one of
the frames does not have a "longdesc" attribute, ask the user
if the relationships between frames are not apparent in the titles for
each frame.
Valid "longdesc" attribute:
Must not be NULL
Must be a valid URI
The file pointed to by the URI must be accessible HTML
If the relationships between frames are not obvious then ask that they
provide a description of the relationships. Allow the user to create a
"longdesc" file or associate an existing
"longdesc" file. It is suggested that each FRAME
in the reference the same "longdesc" as the description of
the relationships should be available from each FRAME.
@@handled by technique 13.1.1 - verify that targets are clearly identified?
What else do we need to check for?
Technique 1.1.12 [priority 1] Verify that valid
text equivalents are provided for PRE and XMP
elements used to create ASCII art.
Open issues for this technique:
A-Prompt has been using an algorithm to detect ASCII art (There must be
5 or more lines of text and there must be 5 or more same characters in a
sequence). This works quite well but detects things such as code samples
(don't require text equiv.) and guitar tabulature (do require text equiv.)
Should we suggest this algorithm in the evaluation?
What about ASCII art that is interspersed in text, such as in
P elements?
Bill Shackleton suggested that a tool use a library of well-known ascii
art to detect some ascii art such as emoticons. Yahoo
maintains a list of ascii art one list is specifically about smileys.
Display the multimedia file and allow the user to create an audio
description of the important information.
Allow the user to add a link to an existing audio description file.
Checkpoint 1.4 - 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
Technique 1.4.1 [priority 1]
Verify that multimedia have synchronized equivalents.
Requirement: SMIL files should have the system-captions
flag for at least one text stream and one auditory stream.
Checkpoint 1.5 - Until user agents render text
equivalents for client-side image map links, provide redundant text links for
each active region of a client-side image map
Technique 1.5.1 [priority 3] Verify
that text links are provided for client-side image maps.
Requirement: Document must contain text links for each active area of
the image map.
Associated text links may be found by searching the document for anchors
with href attribute values that correspond to the
AREA elements in the given usemap.
Checkpoint 2.1 - Ensure that all information
conveyed with color is also available without color, for example from
context or markup
Checkpoint 2.2 - 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
Checkpoint 2.1 - Ensure that all information
conveyed with color is also available without color, for example from context
or markup
Technique 2.1.1 [priority 1] Verify that
information conveyed with color is available without color
Ensure that information is not conveyed through color alone. For
example, when asking for input from users, do not write "Please select an
item from those listed in green." Instead, ensure that information is
available through other style effects (e.g., a font effect) and through
context (e.g,. comprehensive text links).
Display a user notification if any of the color-possible elements are in
the document.
Checkpoint 2.2 - 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
Technique 2.2.1 [priority 3] Test the
color attributes of the following elements for visibility:
BODY bgcolor | text | alink | link | vlink | background
=anything �OR
TABLE bordercolor | bgcolor
=anything �OR
TD | TH � �bgcolor
=anything OR
HR color =anything
OR
any_element
style="any_color_specification"
STYLE "any_color_specification"... STYLE
Where any_color_specification is defined as any CSS
specification which contains:
color | background-color | background-image |
background
Requirement: Determine color visibility.@@needs work?
Ideally, images and multimedia object should also be tested for color
visibility but algorithms are beyond the scope of this specification.
Color visibility can be determined according to the following
algorithm:
(This is a suggested algorithm that is still open to
change.)
Two colors provide good color visibility if the brightness difference and
the color difference between the two colors are greater than a set range.
Color brightness is determined by the following formula:
((Red value X 299) + (Green value X 587) + (Blue value X 114)) / 1000
Note: This algorithm is taken from a formula for converting RGB values to YIQ
values. This brightness value gives a perceived brightness for a color.
Color difference is determined by the following formula:
(maximum (Red value 1, Red value 2) - minimum (Red value 1, Red value 2)) +
(maximum (Green value 1, Green value 2) - minimum (Green value 1, Green value
2)) + (maximum (Blue value 1, Blue value 2) - minimum (Blue value 1, Blue
value 2))
The rage for color brightness difference is 125. The range for color
difference is 500.
When an appropriate markup language exists, use markup rather than
images to convey information. For example, use MathML to mark up
mathematical equations, and style sheets to format text and control
layout
Requirements: Document should contain at least one of the
following:STYLE or LINK rel="stylesheet"
elements within the HEAD element | "style"
attributes on any element | FONT | BASEFONT |
"text," "vlink," "link," and "alink" attributes on
BODY.
If layout tables are identified (see technique 5.1.1), trigger this
check as well. We will inform user that style sheets can be used instead
of layout tables in 5.1.1.
Use style sheets to control layout and presentation. For example, use
the CSS 'font' property instead of the HTML FONT
and BASEFONT elements to control font styles
If style sheets are not used, verify that the author has chosen not to
modify the presentation in any way.
If FONT or BASEFONT elements or "text,"
"vlink," "link," and "alink" attributes on BODY,
suggest or help the author convert the presentation properties to style
sheets.
If the author chooses to convert deprecated markup to style sheets or
add style sheets, trigger technique 6.1 to verify that the document is
readable when style sheets are not applied.
Checkpoint 3.4 - Use relative rather than
absolute units in markup language attribute values and style sheet property
values
Technique 3.4.1 [priority 2] Check
document for relative units of measure.
Requirements For any HTML or CSS element defined to take a
%LENGTH, %PIXELS, %MULTILENGTH, or
%MULTILENGTHS, a validated value should either end with "%"
or begin with "+" or "-" or use the "em" or "ex" units.
Exception: "width" and "height" attributes of
IMG, OBJECT, and APPLET elements.
Improper header nesting: Header levels must not increase by more than
one level per heading. Do not use headings to create font effects; use
style sheets to change font styles.
Q is not supported in today's browsers, thus converting
quotes marks to Q will basically delete the quote marks for
all users. what do we suggest in the meantime?
Display the above user notification and provide the following
suggestions:
For blocks of text that are not in the primary language and are
already enclosed by markup elements such as Paragraph,
DIV or EM, set the "lang"
attribute of the markup element.
For words or phrases that are not in the primary language, enclose
them with a SPAN element and set the SPAN
element's "lang" attribute.
Ensure that all captions and other text equivalents are
checked.
A (somewhat costly) technique for guessing the primary language, is to
check for the use of common words in a language. For example, if you find
"a, the, you, for, is, of, and" then it's English. If you find "le, du,
la, a, se, pour, aux, des, ne" then it's French, etc.
The purpose of the table must be determined before performing an
accessibility evaluation. To help the author make this assessment, the
following language may be used:
Data tables present relational data such as a bus schedule, a comparison
of regional sales figures, or a listing of employee contact information.
Cells in data tables are related to each other and usually must be
perceived as a group.
Layout tables visually format images, text, and other information on the
page such as a navigation bar, or a newspaper page with stories, links,
and images. Each cell in a layout table is normally independent and can be
viewed on its own.
Technique 5.1.2 [priority 1] Check data
table for row and column headers
Your table should identify structural groups of rows and groups of
columns. Label table elements with the "scope",
"headers", and "axis" attributes so that future
browsers and assistive technologies will be able to select data from your
table by filtering on categories.
If the table does contain 2 or more logical levels of row or column
headers, use the HTML 4
table algorithm to show the author how the headers are currently
associated with the cells. If the author determines that the current
mark-up is not sufficient, allow the author to markup the table
TD or TH elements with scope,
axis, or headers attributes.
If the table has nested headings, cells that span multiple columns or
rows, or other relationships that may not be obvious from analyzing the
structure of the table but that may be apparent in a visual rendering of
the table, a valid "summary" attribute may be provided.
For missing summary - "Table is missing a summary." "In the summary,
describe the purpose of the table (either layout or data). For example
''This table charts the number of cups of coffee consumed by each senator,
the type of coffee (decaf or regular), and whether taken with sugar.
Additional help text: A summary of the relationships among cells is
especially important for tables with nested headings, cells that span
multiple columns or rows, or other relationships that may not be obvious
from analyzing the structure of the table but that may be apparent in a
visual rendering of the table. A summary may also describe how the table
fits into the context of the current document. If no caption is provided,
it is even more critical to provide a summary.
Technique 5.5.2 [priority 2] Check TABLE elements for valid
CAPTION element.
Evaluation:
Element: TABLE
Requirement: @@
Suggested message:
This table does not have a caption: A table caption describes the nature
of the table in one to three sentences. For example, "Cups of coffee
consumed by each senator."
Suggested repair:
Allow the author to enter a CAPTION
Checkpoint 5.6 - Provide abbreviations for
header labels
Technique 5.6.1 [priority 3] Check table
for header abbreviations
Valid "src" attribute values must have a suffix of
".htm," ".html," ".shtm," ".shtml," ".cfm," ".cfml," ".asp," ".cgi,"
".pl", ".smil" or target document must have a known public identifier
at the top of file.
Elements: SCRIPT, APPLET, OBJECT
�type=@@?, any_element �event_attribute where
event_attribute is "onmouseover" etc.
Requirements: any actions that change the display must change the
equivalent @@Is this computable in a practical time (cf. NP complete) .
�Computer science help needed here. �Of course, as in other parts of
document, the fact that the equivalent changes is no guarantee that
equivalent is correct than it is guaranteed that "alt" text
for an image is correct.
Requirements: Objects must not contain device dependent event handlers.
@@Does this mean checking Java, Flash, etc? Can we only do this for
scripting? Or prompt the author to check?
A valid NOFRAMES section should exist within each
FRAMESET section
Valid NOFRAMES section
Must contain at least one word of text or accessible HTML code.
The contents of the NOFRAMES element must provide the
necessary links to navigate the site.
Not allowed: Telling the user that they should upgrade to a browser that
supports frames. Suspicious words within the text of a
NOFRAMES element: "upgrade," "full advantage," supports
frames," "missing" etc.
It is desirable that a tool be able to measure flicker. This could be
done by software that renders, takes screenshots and compares. [Len
Kasday, 23 January 2000]
Guideline 8. Ensure direct accessibility of
embedded user interfaces
Checkpoint 8.1 - Make programmatic
elements such as scripts and applets directly accessible or compatible with
assistive technologies
Technique 8.1.1 [priority
1 if functionality is important and not presented elsewhere, otherwise
Priority 2] Verify that programmatic objects are directly accessible.
Tools should include means to test the embedded technologies, e.g. java,
at least by running them, preferably by including any test software
supplied for the technology. [Len
Kasday - 23 January 2000]
Checkpoint 9.1 - Provide client-side
image maps instead of server-side image maps except where the regions
cannot be defined with an available geometric shape.
Checkpoint 9.2 - Ensure that any
element that has its own interface can be operated in a device-independent
manner.
Checkpoint 9.3 - For scripts,
specify logical event handlers rather than device-dependent event
handlers.
Checkpoint 9.4 - Create a logical tab
order through links, form controls, and objects.
Checkpoint 9.5 - Provide keyboard
shortcuts to important links, form controls, and groups of form
controls
Checkpoint 9.1 - Provide client-side image
maps instead of server-side image maps except where the regions cannot be
defined with an available geometric shape
Technique 9.1.1 [priority 1] Check for
use of server-side image maps
Evaluation:
Element:IMG "ismap"
Suggested message:
Use client-side image maps instead of server-side maps.
Suggested repair:
Allow the user to convert the server-side image map to a client-side
image map.
Checkpoint 9.2 - Ensure that any element
that has its own interface can be operated in a device-independent manner
Open issues for this technique:
This technique is strongly tied to Guideline 8 and checkpoint 1.1 (image
maps). Is there redundancy that we can get rid of?
Evaluation:
Elements:
OBJECT type =(@@what are the type attribute values
for Java, etc.?)
EMBED
APPLET
Suggested message:
Ensure this programmatic object can be operated in a device independent
manner.
Suggested repair:
Display a user notification if any of the programmatic objects are in
the document.
Checkpoint 9.3 - For scripts,
specify logical event handlers rather than device-dependent event
handlers
Technique 9.3.1 [priority 2] Check
scripts for logical event handlers
Checkpoint 10.1 - Until user agents allow
users to turn off spawned windows, do not cause pop-ups or other windows
to appear and do not change the current window without informing the
user
Checkpoint 10.2 - Until user agents
support explicit associations between labels and form controls, for all
form controls with implicitly associated labels, ensure that the label is
properly positioned
Checkpoint 10.3 - Until user agents
(including assistive technologies) render side-by-side text correctly,
provide a linear text alternative (on the current page or some other) for
all tables that lay out text in parallel, word-wrapped columns
Checkpoint 10.4 - Until user agents handle
empty controls correctly, include default, place-holding characters in
edit boxes and text areas
Checkpoint 10.5 - Until user agents
(including assistive technologies) render adjacent links distinctly,
include non-link, printable characters (surrounded by spaces) between
adjacent links
Checkpoint 10.1 - Until user agents allow
users to turn off spawned windows, do not cause pop-ups or other windows to
appear and do not change the current window without informing the user
Technique 10.1.1 [priority 1] Check
A and AREA elements for valid "target"
attributes
Allow the user to remove the scripting code that opens a new
window.
Checkpoint 10.2 - Until user agents
support explicit associations between labels and form controls, for all form
controls with implicitly associated labels, ensure that the label is properly
positioned
Labels for form controls should be positioned close to their
corresponding form controls. This control [control type] does not have a
closely positioned label.
Allow the user to reposition labels associated with form controls as
follows:
Labels for radio buttons and checkboxes should appear after the
radio button or checkbox. For example: [checkbox] oranges, [checkbox]
apples.
Labels for text fields appear before the text field. For example:
last name [text area].
Labels for groups of any form control should appear before the
group. For example: choose a city [radio button] Boston [radio button]
Madison.
Checkpoint 10.3 - Until user agents (including
assistive technologies) render side-by-side text correctly, provide a linear
text alternative (on the current page or some other) for all tables that lay
out text in parallel, word-wrapped columns
Please consult the definition of linearized table. This checkpoint
benefits people with user agents (such as some screen readers) that are
unable to handle blocks of text presented side-by-side; the checkpoint
should not discourage content developers from using tables to represent
tabular information.
If it has been determined that the table is used for layout (see
Technique 5.1.1) then create a linear version of the table by: [@@insert
heuristics from table linearizer - basically replace TABLE
markup with text structural markup]. The author will then need to check
that it is readable.
If it has been determined that the table is used for data (see Technique
5.1.1) then create a linear version of the table by: [@@table linearizer
heuristics? basically, for each cell repeat the column and row headers
associated with it]. The author will then need to check that it is
readable.
INPUT element missing value: Allow user to enter
placeholder text.
TEXTAREA missing text: Allow user to enter text.
OPTION not selected: Display all options and allow user to
select one as "selected".
Checkpoint 10.5 - Until user agents (including
assistive technologies) render adjacent links distinctly, include non-link,
printable characters (surrounded by spaces) between adjacent links
Checkpoint 11.1 - Use W3C technologies
when they are available and appropriate for a task and use the latest
versions when supported
Checkpoint 11.2 - Avoid deprecated
features of W3C technologies
Checkpoint 11.3 - Provide information
so that users may receive documents according to their preferences
Checkpoint 11.4 - If, after best efforts, you
cannot create an accessible page, provide a link to an alternative page
that uses W3C technologies, is accessible, has equivalent information (or
functionality), and is updated as often as the inaccessible (original)
page
Checkpoint 11.1 - Use W3C technologies when
they are available and appropriate for a task and use the latest versions when
supported
Many of these W3C formats are not widely supported yet. Therefore, how
do we deal with this in the meantime? Present the info and let the author
decide?
Non-W3C technology used: W3C technologies have been reviewed for
accessibility issues throughout the design phase and have accessibility
built-in. Many non-W3C formats require specific applications (often called
plug-ins) that are inaccessible or do not work well with assistive
technologies. Using W3C technologies will tend to make pages more
accessible to more people using a wider variety of hardware and software.
If inaccessible technologies (proprietary or not) must be used, equivalent
accessible pages must be provided.
Prompt user to specify language of document in technique 4.3.1.
Use CC/PP or XML/XSLT or other transformations on the server or gateway
to configure a page for various user preferences and device profiles.
Serve style sheets based on user preferences - use the media types.
Work with your server system administrator to provide content
negotiation.
Use browser sniffing on the client to request documents on the
server.
Use cookies to remember user preferences between sessions and server
documents per those preferences.
Link to other versions of the document (other formats and
languages).
If not possible to use content negotiation, indicate content type or
language through markup (e.g., in HTML use "type" and
"hreflang").
Checkpoint 11.4 - If, after best efforts, you
cannot create an accessible page, provide a link to an alternative page that
uses W3C technologies, is accessible, has equivalent information (or
functionality), and is updated as often as the inaccessible (original)
page
This document does not conform to the WCAG guidelines. If you are unable
to make the necessary repairs to this document then please create another
equivalent page that is accessible and link to it from this document.
Harper, S., Stevens, R., and Goble, C. (1999). Towel: Real World Mobility
on the Web. In Vanderdonckt, J. and Puerta, A., eds.: Computer-Aided Design of
User Interfaces II. Dordrecht, Netherlands: Kluwer Academic Publishers.
Checkpoint 13.2 - Provide metadata to add
semantic information to pages and sites
If no META, ADDRESS, TITLE or LINK elements
are found, request information from the author to be stored as meta
information. Examples of content to prompt for:
title of the page (required for frames, see checkpoint 12.1),
type of content,
descriptions of the content of the page,
conformance claims,
author information,
next page in a series (e.g., LINK rel="next").
If a LINK element is found, check if it is used for style
sheets. If it is, then proceed as if no LINK element were
found.
If a META element is found, check if it is used to create a
redirect. If it is, then proceed as if no META element were
found (refer also to checkpoints 7.4 and 7.5).
Ask the user if an identified list of links should be grouped.
If the user wants to group the links, use one of the following
techniques
a MAP element
SPAN or DIV with appropriate
"title"
Suggest that the user provide a link to bypass the group or that they
move the group to the bottom of the page or that they use a high
"tabindex" attribute value.
Checkpoint 13.7 - If search functions are provided,
enable different types of searches for different skill levels and
preferences
When providing search functionality, content developers should offer
search mechanisms that satisfy varying skill levels and preferences. Most
search facilities require the user to enter keywords for search terms.
Users with spelling disabilities and users unfamiliar with the language of
your site will have a difficult time finding what they need if the search
requires perfect spelling. Search engines might include a spell checker,
offer "best guess" alternatives, query-by-example searches, similarity
searches, etc.
Checkpoint 13.8 - Place distinguishing
information at the beginning of headings, paragraphs, lists, etc
@@Machine checkable? Generate user notification?
Checkpoint 13.9 - Provide information about
document collections
Requirement: If the page is part of a collection, such as a slide show,
or a chapter in a book, the previous and next pages ought to be marked as
such.
Consistent page layout and recognizable graphics benefit all users. In
particular, they help people with cognitive disabilities or who have
difficulty reading.
If style properties vary between pages, or various external style sheets
are used, suggest the author consolidate style properties into external
style sheets and use consistently.
After evaluating a document, an evaluation and/or repair tool should
provide the user with a document rating. The rating is based on conformance to
the W3C Web Content
Accessibility Guidelines and will be:
Level "A": all Priority 1 checkpoints are
satisfied;
Level "Double-A": all Priority 1 and 2 checkpoints are
satisfied;
Level "Triple-A": all Priority 1, 2, and 3 checkpoints
are satisfied;
Some checkpoints can not be checked by a software program and will require
user evaluation. The user must be informed of the items that they must
check.
An object that is embedded in a document with the SCRIPT or
APPLET elements, and sometimes with the OBJECT or EMBED
elements. @@need to clarify the definition and then use it.
