Saturday, February 18, 2023

WCAG2.0 and P.O.U.R Concept

The Web Content Accessibility Guidelines (WCAG) 2.0 includes a comprehensive set of success criteria organized under the four principles of Perceivable, Operable, Understandable, and Robust (POUR). WCAG 2.0 encompasses a total of 38 success criteria for Level A and an additional 26 success criteria for Level AA accessibility compliance.

In WCAG 2.0, Level A success criteria focus on fundamental accessibility requirements, while Level AA success criteria address more advanced considerations to enhance the user experience for individuals with disabilities. Think of Level A success criteria in WCAG 2.0 as the basic building blocks of accessibility, like providing text alternatives for images (1.1.1) or ensuring keyboard accessibility (2.1.1). On the other hand, Level AA success criteria, such as maintaining sufficient contrast (1.4.3) or offering alternatives for time-based media (1.2.2), take accessibility a step further for a more inclusive and refined user experience.

Perceivable

1. Text Alternatives (Provide text alternatives for non-text content):

    1.1.1 Non-text Content: All non-text content that is presented to the user has a text alternative that serves the equivalent purpose.

2. Time-based Media (Provide alternatives for time-based media):

    1.2.1 Audio-only and Video-only (Prerecorded): Provide an alternative for time-based media.

    1.2.2 Captions (Prerecorded): Provide synchronized captions for multimedia.

    1.2.3 Audio Description or Media Alternative (Prerecorded): Provide an alternative for time-based media or audio descriptions.

3. Adaptable (Create content that can be presented in different ways without losing information or structure):

    1.3.1 Info and Relationships: Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text.

    1.3.2 Meaningful Sequence: When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined.

    1.3.3 Sensory Characteristics: Instructions provided for understanding and operating content do not rely solely on sensory characteristics.

4. Distinguishable (Make it easier for users to see and hear content):

    1.4.1 Use of Color: Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.

    1.4.2 Audio Control: If any audio on a Web page plays automatically for more than 3 seconds, a mechanism is available to pause or stop the audio.

    1.4.3 Contrast (Minimum): Text and images of text have a contrast ratio of at least 4.5:1.

    1.4.4 Resize text: Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.

Operable

5. Keyboard Accessible (Make all functionality available from a keyboard):

    2.1.1 Keyboard: All functionality of the content is operable through a keyboard interface.

6. Enough Time (Provide users enough time to read and use content):

    2.2.1 Timing Adjustable: For each time limit that is set by the content, the user is able to turn off, adjust, or extend the time limit.

    2.2.2 Pause, Stop, Hide: For moving, blinking, scrolling, or auto-updating information, there is a mechanism for the user to pause, stop, or hide it.

    2.2.3 No Timing: Timing is not an essential part of the event or activity presented by the content, except for non-interactive synchronized media and real-time events.

7. Seizures and Physical Reactions (Do not design content in a way that is known to cause seizures or physical discomfort):

    2.3.1 Three Flashes or Below Threshold: Web pages do not contain anything that flashes more than three times in any one-second period, or the flash is below the general flash and red flash thresholds.

    2.3.2 Three Flashes: Web pages do not contain anything that flashes more than three times in any one-second period.

8. Navigable (Provide ways to help users navigate, find content, and determine where they are):

    2.4.1 Bypass Blocks: A mechanism is available to bypass blocks of content that are repeated on multiple Web pages.

    2.4.2 Page Titled: Web pages have titles that describe the topic or purpose.

    2.4.3 Focus Order: If a Web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability.

    2.4.4 Link Purpose (In Context): The purpose of each link can be determined from the link text alone or from the link text together with its link context.

    2.4.5 Multiple Ways: More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process.

    2.4.6 Headings and Labels: Headings and labels describe topic or purpose.

    2.4.7 Focus Visible: Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible.

Understandable

9. Readable (Make text content readable and understandable):

    3.1.1 Language of Page: The default human language of each Web page can be programmatically determined.

    3.1.2 Language of Parts: The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, and words or phrases that have become part of the vernacular of the immediately surrounding text.

10. Predictable (Make web pages appear and operate in predictable ways):

    3.2.1 On Focus: When any component receives focus, it does not initiate a change of context.

    3.2.2 On Input: Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component.

    3.2.3 Consistent Navigation: Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user.

    3.2.4 Consistent Identification: Components that have the same functionality within a set of Web pages are identified consistently.

11. Input Assistance (Help users avoid and correct mistakes):

    3.3.1 Error Identification: If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text.

    3.3.2 Labels or Instructions: Labels or instructions are provided when content requires user input.

    3.3.3 Error Suggestion: If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content.

    3.3.4 Error Prevention (Legal, Financial, Data): For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true:

Robust

12. Compatible (Maximize compatibility with current and future user agents, including assistive technologies):

    4.1.1 Parsing: In content implemented using markup languages, elements have complete start and end tags, elements are nested according to their specifications, elements do not contain duplicate attributes, and any IDs are unique, except where the specifications allow these features.

    4.1.2 Name, Role, Value: For all user interface components (including but not limited to: form elements, links and components generated by scripts), the name and role can be programmatically determined; states, properties, and 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.


This list is a comprehensive overview of the WCAG 2.0 success criteria, organized under the Perceivable, Operable, Understandable, and Robust principles. Each success criterion plays a crucial role in ensuring digital content is accessible to a diverse audience.

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