Accessibility

Accessibility:
The title is self explanatory, or is it?

(In human-computer interaction, computer accessibility (also known as accessible computing) refers to the accessibility a computer system to all people, regardless of disability or severity of impairment. It is largely a software concern; when software, hardware, or a combination of hardware and software, is used to enable use of a computer by a person with a disability or impairment, this is known as Assistive Technology.)

This definition is taken from Wikipedia and sums up the problems that web designers and software designers have to deal with.

Web accessibility means that people with disabilities can use the Web. More specifically, Web accessibility means that people with disabilities can perceive, understand, navigate, and interact with the Web, and that they can contribute to the Web. Web accessibility also benefits others, including older people with changing abilities due to aging.

Much has been written about this subject and W3C have produced a working draft on the subject, see below...

This section is informative.

The Web Content Accessibility Guidelines 2.0 Checklist serves as an appendix to Web Content Accessibility Guidelines 2.0 [WCAG20]. It lists all of the success criteria from WCAG 2.0 in a checkable list. The level of each success criterion is provided as well as a link to WCAG 2.0 for more information for each success criterion. For many readers, the Checklist provides a quick reference and overview to the information in WCAG 2.0.

Success Criteria

Guideline 1.1 : Provide text alternatives for all non-text content
	True	Success Criterion	Comments
L1		*1.1.1* For all non-text content, one of the following is true: [How to meet 1.1.1] If non-text content presents information or responds to user input, text alternatives serve the same purpose and present the same information as the non-text content. If text alternatives cannot serve the same purpose, then text alternatives at least identify the purpose of the non-text content. If non-text content is multimedia; live audio-only or live video-only content; a test or exercise that must use a particular sense; or primarily intended to create a specific sensory experience; then text alternatives at least identify the non-text content with a descriptive text label. (For multimedia, see also Guideline 1.2 Provide synchronized alternatives for multimedia .) If the purpose of non-text content is to confirm that content is being operated by a person rather than a computer, different forms are provided to accommodate multiple disabilities. If non-text content is pure decoration, or used only for visual formatting, or if it is not presented to users, it is implemented such that it can be ignored by assistive technology.

Guideline 1.2 : Provide synchronized alternatives for multimedia
	True	Success Criterion	Comments
L1		*1.2.1* Captions are provided for prerecorded multimedia. [How to meet 1.2.1]
L1		*1.2.2* Audio descriptions of video, or a full multimedia text alternative including any interaction, are provided for prerecorded multimedia. [How to meet 1.2.2]
L2		*1.2.3* Audio descriptions of video are provided for prerecorded multimedia. [How to meet 1.2.3]
L2		*1.2.4* Captions are provided for live multimedia. [How to meet 1.2.4]
L3		*1.2.5* Sign language interpretation is provided for multimedia. [How to meet 1.2.5]
		*1.2.6* Extended audio descriptions of video are provided for prerecorded multimedia. [How to meet 1.2.6]
		*1.2.7* For prerecorded multimedia, a full multimedia text alternative including any interaction is provided. [How to meet 1.2.7]

Guideline 1.3 : Ensure that information and structure can be separated from presentation
	True	Success Criterion	Comments
L1		*1.3.1* Information and relationships conveyed through presentation can be programmatically determined, and notification of changes to these is available to user agents, including assistive technologies. [How to meet 1.3.1]
		*1.3.2* Any information that is conveyed by color is also visually evident without color. [How to meet 1.3.2]
		*1.3.3* When the sequence of the content affects its meaning, that sequence can be programmatically determined. [How to meet 1.3.3]
L2		*1.3.4* Information that is conveyed by variations in presentation of text is also conveyed in text, or the variations in presentation of text can be programmatically determined. [How to meet 1.3.4]
L2		*1.3.5* Information required to understand and operate content does not rely on shape, size, visual location, or orientation of components. [How to meet 1.3.5]

Guideline 1.4 : Make it easy to distinguish foreground information from its background
	True	Success Criterion	Comments
L2		*1.4.1* Text or diagrams, and their background, have a luminosity contrast ratio of at least 5:1. [How to meet 1.4.1]
L2		*1.4.2* A mechanism is available to turn off background audio that plays automatically, without requiring the user to turn off all audio. [How to meet 1.4.2]
L3		*1.4.3* Text or diagrams, and their background, have a luminosity contrast ratio of at least 10:1. [How to meet 1.4.3]
L3		*1.4.4* Audio content does not contain background sounds, background sounds can be turned off, or background sounds are at least 20 decibels lower than the foreground audio content, with the exception of occasional sound effects. [How to meet 1.4.4] Note: A 20 decibel difference in sound level is roughly four times (4x) quieter or louder. Background sound that meets this requirement will be approximately four times (4x) quieter than the foreground audio content.

Guideline 2.1 : Make all functionality operable via a keyboard interface
	True	Success Criterion	Comments
L1		*2.1.1* All functionality of the content is operable in a non-time-dependent manner through a keyboard interface, except where the task requires analog, time-dependent input. [How to meet 2.1.1] Note: This does not preclude and should not discourage the support of other input methods (such as a mouse) in addition to keyboard operation.
L3		*2.1.2* All functionality of the content is operable in a non-time-dependent manner through a keyboard interface. [How to meet 2.1.2]

Guideline 2.2 : Allow users to control time limits on their reading or interaction
	True	Success Criterion	Comments
L1		*2.2.1* For each time-out that is a function of the content, at least one of the following is true: [How to meet 2.2.1] the user is allowed to deactivate the time-out; or the user is allowed to adjust the time-out over a wide range that is at least ten times the length of the default setting; or the user is warned before time expires and given at least 20 seconds to extend the time-out with a simple action (for example, "hit any key"), and the user is allowed to extend the timeout at least ten times; or the time-out is an important part of a real-time event (for example, an auction), and no alternative to the time-out is possible; or the time-out is part of an activity where timing is essential (for example, competitive gaming or time-based testing) and time limits can not be extended further without invalidating the activity.
L2		*2.2.2* Content does not blink for more than three seconds, or a method is available to stop all blinking content in the Web unit or authored component. [How to meet 2.2.2] Note: For requirements related to flickering or flashing content, refer to Guideline 2.3 Allow users to avoid content that could cause seizures due to photosensitivity .
L2		*2.2.3* Content can be paused by the user unless the timing or movement is part of an activity where timing or movement is essential. [How to meet 2.2.3]
L3		*2.2.4* Except for real-time events, timing is not an essential part of the event or activity presented by the content. [How to meet 2.2.4]
		*2.2.5* Interruptions, such as updated content, can be postponed or suppressed by the user, except interruptions involving an emergency. [How to meet 2.2.5]
		*2.2.6* When an authenticated session expires, the user can continue the activity without loss of data after re-authenticating. [How to meet 2.2.6]

Guideline 2.3 : Allow users to avoid content that could cause seizures due to photosensitivity
	True	Success Criterion	Comments
L1		*2.3.1* Content does not violate the general flash threshold or the red flash threshold. [How to meet 2.3.1]
L3		*2.3.2* Web units do not contain any components that flash more than three times in any 1-second period. [How to meet 2.3.2]

Guideline 2.4 : Provide mechanisms to help users find content, orient themselves within it, and navigate through it
	True	Success Criterion	Comments
L1		*2.4.1* A mechanism is available to bypass blocks of content that are repeated on multiple Web units. [How to meet 2.4.1]
L2		*2.4.2* More than one way is available to locate content within a set of Web units where content is not the result of, or a step in, a process or task. [How to meet 2.4.2]
		*2.4.3* Web units have titles. [How to meet 2.4.3]
		*2.4.4* Each link is programmatically associated with text from which its purpose can be determined. [How to meet 2.4.4]
L3		*2.4.5* Titles, headings, and labels are descriptive. [How to meet 2.4.5]
		*2.4.6* When a Web unit or authored component is navigated sequentially, components receive focus in an order that follows relationships and sequences in the content. [How to meet 2.4.6]
		*2.4.7* Information about the user's location within a set of Web units is available. [How to meet 2.4.7]
		*2.4.8* The purpose of each link can be programmatically determined from the link. [How to meet 2.4.8]

Guideline 2.5 : Help users avoid mistakes and make it easy to correct mistakes that do occur
	True	Success Criterion	Comments
L1		*2.5.1* If an input error is detected, the error is identified and described to the user in text. [How to meet 2.5.1]
L2		*2.5.2* If an input error is detected and suggestions for correction are known and can be provided without jeopardizing the security or purpose of the content, the suggestions are provided to the user. [How to meet 2.5.2]
L2		*2.5.3* For forms that cause legal or financial transactions to occur, that modify or delete data in data storage systems, or that submit test responses, at least one of the following is true: [How to meet 2.5.3] Actions are reversible. Actions are checked for input errors before going on to the next step in the process. The user is able to review and confirm or correct information before submitting it.
L3		*2.5.4* Context-sensitive help is available for text input. [How to meet 2.5.4]

Guideline 3.1 : Make text content readable and understandable.
	True	Success Criterion	Comments
L1		*3.1.1* The primary natural language or languages of the Web unit can be programmatically determined. [How to meet 3.1.1]
L2		*3.1.2* The natural language of each passage or phrase in the Web unit can be programmatically determined. [How to meet 3.1.2] Note: This requirement does not apply to individual words or phrases that have become part of the primary language of the content.
L3		*3.1.3* A mechanism is available for identifying specific definitions of words or phrases used in an unusual or restricted way, including idioms and jargon. [How to meet 3.1.3]
		*3.1.4* A mechanism for finding the expanded form of abbreviations is available. [How to meet 3.1.4]
		*3.1.5* When text requires reading ability more advanced than the lower secondary education level, supplemental content is available that does not require reading ability more advanced than the lower secondary education level. [How to meet 3.1.5]
		*3.1.6* A mechanism is available for identifying specific pronunciation of words where meaning cannot be determined without pronunciation. [How to meet 3.1.6]

Guideline 3.2 : Make the placement and functionality of content predictable.
	True	Success Criterion	Comments
L1		*3.2.1* When any component receives focus, it does not cause a change of context. [How to meet 3.2.1]
L1		*3.2.2* Changing the setting of any form control or field does not automatically cause a change of context (beyond moving to the next field in tab order), unless the authored unit contains instructions before the control that describe the behavior. [How to meet 3.2.2]
L2		*3.2.3* Navigational mechanisms that are repeated on multiple Web units within a set of Web units or other primary resources occur in the same relative order each time they are repeated, unless a change is initiated by the user. [How to meet 3.2.3]
L2		*3.2.4* Components that have the same functionality within a set of Web units are identified consistently. [How to meet 3.2.4]
L3		*3.2.5* Changes of context are initiated only by user request. [How to meet 3.2.5]

Guideline 4.1 : Support compatibility with current and future user agents (including assistive technologies)
	True	Success Criterion	Comments
L1		*4.1.1* Web units or authored components can be parsed unambiguously, and the relationships in the resulting data structure are also unambiguous. [How to meet 4.1.1]
L1		*4.1.2* For all user interface components, the name and role can be programmatically determined, values that can be set by the user can be programmatically set, and notification of changes to these items is available to user agents, including assistive technologies. [How to meet 4.1.2]

Guideline 4.2 : Ensure that content is accessible or provide an accessible alternative
	True	Success Criterion	Comments
L1		*4.2.1* At least one version of the content meets all level 1 success criteria, but alternate version(s) that do not meet all level 1 success criteria may be available from the same URI. [How to meet 4.2.1]
L1		*4.2.2* Content meets the following criteria even if the content uses a technology that is not in the chosen baseline: [How to meet 4.2.2] If content can be entered using the keyboard, then the content can be exited using the keyboard. Content conforms to success criterion 2.3.1 (general and red flash).
L2		*4.2.3* At least one version of the content meets all level 2 success criteria, but alternate version(s) that do not meet all level 2 success criteria may be available from the same URI. [How to meet 4.2.3]
L3		*4.2.4* Content implemented using technologies outside of the chosen baseline satisfies all Level 1 and Level 2 requirements supported by the technologies. [How to meet 4.2.4]

To meet these guidelines is the challenge that all Web designers must realise, as well as the importance of constantly reviewing output and being prepared to change and adapt as needed. We all need the world to be accessible.

External Links

Classy Links

Accessibility

This section is informative.

Success Criteria