Week 7 Essential Components of Web Accessibility

Since we learned and studied the accessibility parts this week, I chose an article, which introduces the essential components of web accessibility. Here is the link: http://www.w3.org/WAI/intro/components.php


So, the first question we may ask is, "what are the essential components of web accessibility?" As the author mentioned, these components include:

• content - the information in a Web page or Web application, including: 1) natural information such as text, images, and sounds, and 2) code or markup that defines structure, presentation, etc.


• Web browsers, media players, and other "user agents"


• assistive technology, in some cases - screen readers, alternative keyboards, switches, scanning software, etc.


• users' knowledge, experiences, and in some cases, adaptive strategies using the Web


• developers - designers, coders, authors, etc., including developers with disabilities and users who contribute content


• authoring tools - software that creates Web sites


• evaluation tools - Web accessibility evaluation tools, HTML validators, CSS validators, etc.

The author also indicates that these components work together for achieving accessibility. The components are actually related. Below is a figure to show the relationship between them.





Web developers usually use authoring tools and evaluation tools to create Web content.
People ("users") use Web browsers, media players, assistive technologies, or other "user agents" to get and interact with the content.

And interdependencies between components exist, e.g. for alternative text on images:

• Technical specifications address alternative text (for example, HTML defines the alternative text attribute (alt) of the image element (img))


• WAI guidelines - WCAG(Web Content Accessibility Guidelines), ATAG(Authoring Tool Accessibility Guidelines), and UAAG(User Agent Accessibility Guidelines), these guidelines define how to implement alternative text for accessibility in the different components


• Developers provide the appropriate alternative text wording


• Authoring tools enable, facilitate, and promote providing alternative text in a Web page


• Evaluation tools are used to help check that alternative text exists


• User agents provide human and machine interface to the alternative text


• Assistive technologies provide human interface to the alternative text in various modalities


• Users know how to get the alternative text from their user agent and/or assistive technology as needed

After reading this article, I think those 7 essential components are really important and needed. For accessibility, the website should be designed to be usable to all people, even the disabilities. Therefore, the website needs to be carefully designed, developed and edited. It's the developers' job to design and maintain the website. The users are also involved, if those website design can base on users' habits and needs, etc, so the website can satisfy them. The content is presented to user and it is the information which users are looking for, so it is needed to be well organized and carefully designed. To ensure the design's quality, we need the technologies and tools (Authoring tools, Evaluation tools and Assistive technologies). And developers can follow the guidelines to check if the website design is considered to be accessible. There are also web browsers, media needed to support the design.