W3C – Web Content Accessibility Guidelines (WCAG) 2.0

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Nov 15, 2013 (3 years and 6 months ago)

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Student Affairs Communications Group


Web Accessibility Handouts


1


S
TUDENT
A
FFAIRS
C
OMMUNICATIONS
G
ROUP


W
EB
A
CCESSIBILITY
H
ANDOUTS

December 1, 2010


Gabriel Merrell from Disability Access Services

W3C



W
EB
C
ONTENT
A
CCESSIBILITY
G
UIDELINES
(WCAG)

2.0


Quick Reference

(
HTTP
://
WWW
.
W
3.
ORG
/WAI/WCAG20/
QUICKREF
/
)


Official Specs at

(
HTTP
://
WWW
.
W
3.
ORG
/TR/WCA
G20/
)



These guidelines have been developed using four principles; Perceivable, Operable, Understandable & Robust. Within
each principle are guidelines (e.g. 1.2) and within each guideline there are specific success criteria (e.g. 1.2.7


some
listed on t
he second page of this handout). Three success levels are defined for the success criteria; A, AA, AAA. Level A
is the minimum level of conformance, with AA (which includes all of level A and AA) being my recommended level for
accessibility, and AAA (whic
h includes all three levels) a good goal but even WCAG recognizes it is impossible to meet
AAA for some content and thus would not make a good general policy.


P
ERCEIVABLE

1.1
Text Alte
rnatives:

Provide text alternatives for any non
-
text content so that it can be changed into other
forms people need, such as large print, braille, speech, symbols or simpler language.

1.2
Time
-
based Media:

Provide alternatives for time
-
based media.

1.3
Adaptable:

Create content that c
an be presented in different ways (for example simpler layout) without
losing information or structure.

1.4
Distinguishable:

Make it easier for users to see and hear content including separating foreground from
background.

O
PERABLE

2.1
Keyboard Accessible:

Make all functionality available from a keyboard.

2.2
Enough Time:

Provide users enough time to read and

use content.

2.3

Seizures:

Do not design content in a way that is known to cause seizures.

2.4
Navigable:

Provide ways to help users navigate, find content, and determine where they are.

U
NDERSTANDABLE

3.1
Readable:

Make text content readable and understandable.

3.2
Predictable:

Make Web pages appear and operate in predictable ways.

3.3
Input Assistance:

Help users
avoid and correct mistakes.

R
OBUST

4.1
Compatible:

Maximize compatibility with current and future user agents, including assistive technologies.

Student Affairs Communications Group


Web Accessibility Handouts


2


WCAG

2.0

S
UCCESS
C
RITERIA
L
EVEL
A



A

MINIMUM LEVEL OF CON
FORMANCE FOR ACCESSI
BILITY


This is a sample of WCAG criteria with my thoughts on what the most important points are

(items marked with an *
asterisk seem most applicable for you). For the full standards and WCAG language please visit their site.
*
1.1.1.

Non
-
text Content



Alt text on images, form image but
tons, image
maps, audio, video
, form labels



Images with no meaning <alt=””>

*
1.2.1.
Prerecorded Audio
-
only and Video
-
only



For Audio
-
only


descriptive
text transcript



For Video
-
only


text or audio description

*
1.2.2.

Captions (Prerecorded)



Synchronized captions for non
-
live multimedia

1.2.3.
Audio Description or Media Alternative
(Prerecorded)



Text transcript or audio description track

*
1.3.1.

Info and Relationships



Use appropriate semantic markup; <h1>

<ul>
<ol> <dl> etc.



Use tables only for tabular data and <caption>
summary=”” where appropriate



Code form input elements with <label>

*
1.3.2.
Meaningful Sequence



Make
sure reading/
nav
igation

order is logical

1.3.3.
Sensory Characteristics



Instructions don’t rely on
shape/size/location/sound

1.4.1.
Use of Color



Not sole method for conveying content/links

1.4.2.
Audio Control



User must be able to control audio

2
.1.1.
Keyboard



All functionality must be available by keyboard

2.1.2.
No Keyboard Trap



User

can navigate using only keyboard

2.2.1.
Timing Adjustable



If time limit, user must be able to extent

*
2.2.2.
Pause, Stop, Hide



Auto moving/blinking/scrolling content longer
than
5

sec must be controllable

2.3.1.
Three Flashe
s or Below Threshold



No content can flash more than 3 times/sec

2.4.1.
Bypass Blocks



Links to skip nav and other repetitive elements

2.4.2.
Page Titled



Every page must have a <title> in <head>

2.4.3.
Focus Order



Content must be logical
and intuitive (
i.e.
nav)



Focus highlight must be highly visible for all

*
2.4.4.
Link Purpose (In Context)



Purpose of link must be
clear

from link alone

3.1.1.
Language of Page



Page language must be defined
using lang
attribute (i.e.
<html lang=”en”>
)

3.2.1.
On Fo
cus



When element receives focus, must not result in
substantial change

(i.e. pop
-
up or open page)

3.2.2.
On Input



User input must not result in change
, unless
inform
ed ahead of time

*
3.3.1.
Error Identification



In
content like
form submission, if there are
errors a user must be notified

*
3.3.2.

Labels or Instructions



Labels, cues, instructions provided for elements
(i.e. forms)


associate labels with form controls

4.1.1.
Parsing



Avoid HTML/XHTML validation/parsing errors

4.1.2.
Name, Role, Value



Follow specs for markup (HTML/XHTML)

Student Affairs Communications Group


Web Accessibility Handouts


3


S
ECTION
508:

§

1194.22




W
EB
-
BASED INTRANET AND I
NTERNET
INFORMATION AND APPL
ICATIONS

(a) A text equivalent for every non
-
text element
shall be provided (
e.g.
, via “
alt
”, “
longdesc
”, or in
element content).


(b) Equivalent alternatives for any multimedia
presentation shall be synchronized with the
presentation.


(c) Web pages shall be designed so that all
information conveyed with color is also available
without color, for example from context or markup.


(d) Documents shall be organized so they are
readable without requiring an associated style
sheet.


(e) Redun
dant text links shall be provided for each
active region of a server
-
side image map.


(f) Client
-
side image maps shall be provided
instead of server
-
side image maps except where
the regions cannot be defined with an available
geometric shape.


(g) Row and
column headers shall be identified for
data tables.


(h) Markup shall be used to associate data cells
and header cells for data tables that have two or
more logical levels of row or column headers.


(i) Frames shall be titled with text that facilitates
fra
me identification and navigation.


(j) Pages shall be designed to avoid causing the
screen to flicker with a frequency greater than 2 Hz
and lower than 55 Hz.


(k) A text
-
only page, with equivalent information or
functionality, shall be provided to make a
web site
comply with the provisions of this part, when
compliance cannot be accomplished in any other
way.


The content of the text
-
only page shall be
updated whenever the primary page changes.


(l) When pages utilize scripting languages to
display content
, or to create interface elements, the
information provided by the script shall be identified
with functional text that can be read by assistive
technology.


(m) When a web page requires that an applet, plug
-
in or other application be present on the client

system to interpret page content, the page must
provide a link to a plug
-
in or applet that complies
with §1194.21(a) through (l).


(n) When electronic forms are designed to be
completed on
-
line, the form shall allow people
using assistive technology to ac
cess the
information, field elements, and functionality
required for completion and submission of the form,
including all directions and cues.


(o) A method shall be provided that permits users
to skip repetitive navigation links.


(p) When a timed response is required, the user
shall be alerted and given sufficient time to indicate
more time is requir
ed