In the previous article, we observed that the lack of access to web pages typically results from failures in the interaction between User and Content components. This difficulty often stems from a malfunctioning relationship between two or more web components. For instance, a weak connection between the developer and the authoring tool can lead to poorly designed content. This situation can worsen if content validation tools do not follow clear rules to evaluate content properly. Therefore, the most effective solution to ensure that all components work in harmony is to establish a set of rules highlighting the critical points of accessibility.
Currently, there are various international documents that propose accessibility rules for the web, aimed at guiding developers of authoring tools, evaluation tools, and content developers. However, all these documents are based on W3C guidelines. That’s why, in this article, we will address the fundamental aspects of the W3C’s Web Accessibility Initiative (WAI) guidelines and briefly discuss their organization.
W3C Guidelines for Digital Content Accessibility
The World Wide Web Consortium (W3C) is widely recognized for its role in developing documents that specify web technologies, such as HTML, XHTML, CSS, among others. These specifications are crucial to ensuring the interoperability and continuous evolution of the web.
The W3C’s main goal is to develop technological standards that allow for the creation and interpretation of content on the web in an accessible and universal manner. The central idea is that websites and web applications built according to these standards are accessible to everyone, regardless of the hardware or software they use.
The W3C, through its Web Accessibility Initiative (WAI), develops guidelines focused on web accessibility. These guidelines are specific to different component groups, ensuring that everyone can benefit from the web equitably. Component groups include authoring tool manufacturers, browser developers, and of course, web content creators. Each has a specific set of guidelines aimed at facilitating the creation and access to accessible content, as described below. Specific guidelines exist for different component groups:
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ATAG (Authoring Tool Accessibility Guidelines) - The ATAG guidelines are aimed at content authoring tool manufacturers, such as Adobe and Microsoft. They guide manufacturers in integrating features into their products to help content developers follow the recommendations outlined in the WCAG. Examples of authoring tools include Adobe Dreamweaver and Microsoft Word. The ATAG working group comprises specialists in authoring tool development, accessibility researchers, and representatives from the software industry. Currently, ATAG’s primary objective is to ensure that authoring tools not only produce accessible content but are also accessible to all users, including people with disabilities. For example, ensuring that text formatting features in an editor can be used by individuals with motor impairments.
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UAAG (User Agent Accessibility Guidelines) - The UAAG guidelines target web browser and media player developers, such as Google Chrome, Mozilla Firefox, and VLC Media Player, also covering some aspects of assistive technologies. The UAAG working group includes browser developers, assistive technology experts, and representatives of organizations advocating for the rights of people with disabilities. Currently, this group focuses on ensuring that browsers and media players are compatible with assistive technologies, such as screen readers (e.g., JAWS or NVDA), and provide an inclusive and accessible user experience, like supporting subtitles in video players for deaf or hard-of-hearing users.
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WCAG (Web Content Accessibility Guidelines) - The WCAG guidelines target the content of web pages and are primarily used by website developers. Authoring and evaluation tool manufacturers, such as WAVE and Axe, also consult this document to refine their products and improve their compliance with content developers’ work. The WCAG working group is composed of accessibility experts, web developers, academics, and representatives of organizations promoting digital inclusion. Currently, WCAG focuses on expanding its guidelines to cover new and emerging technologies and platforms, such as accessibility in artificial intelligence and augmented reality applications, ensuring that accessibility continues to evolve alongside web development. An example of applying WCAG guidelines would be ensuring that all text on a site has sufficient contrast with the background to be readable by visually impaired individuals.
Web Content Accessibility Guidelines
All these guidelines are founded on the technical specifications of the web, such as HTML, XML, CSS, SVG, and SMIL, which are continuously developed and improved by the W3C. The first version of the Web Content Accessibility Guidelines (WCAG) was published in 1999, marking a fundamental step in ensuring that web content is accessible to all, including people with disabilities. Since then, WCAG has been widely used, cited, and referenced in laws, standards, and documents on digital accessibility worldwide. Over the years, new versions of WCAG have been released, including WCAG 2.0 in 2008, WCAG 2.1 in 2018, and WCAG 2.2 in 2023, reflecting the W3C’s ongoing commitment to ensuring that the web evolves inclusively.
The latest version of the Web Content Accessibility Guidelines (WCAG 2.2) is organized into several layers of advice to help authors and developers create accessible content. At the top are the four fundamental principles underpinning web accessibility: perceivable, operable, understandable, and robust. These principles form the foundation for ensuring that web content is accessible to users with various types of disabilities.
Under these principles are 13 guidelines that define general goals and serve as a guide to help authors understand how to make content more accessible. The guidelines themselves cannot be tested directly, but each includes success criteria that are testable and allow developers to assess conformity. WCAG organize these success criteria into three levels of compliance: Level A (the most basic), Level AA, and Level AAA (the highest).
Additionally, WCAG 2.2 offers a series of sufficient techniques and advisory techniques. Sufficient techniques help authors meet success criteria, while advisory techniques go beyond the minimum requirements by addressing additional accessibility barriers. Common failures to be avoided are also documented. This layered structure—principles, guidelines, success criteria, and techniques—provides comprehensive guidance for creating accessible content and encourages authors to apply all possible techniques to meet the needs of the widest range of users.
In future articles, we will examine each of the 13 guidelines of WCAG 2.2 in detail, highlighting the technical aspects associated with them. Our goal is to provide a deep understanding of how to implement these guidelines in practice, ensuring that digital content meets accessibility criteria and offers an inclusive experience for all users. While addressing each guideline, we will also present concrete examples and techniques that can be applied to improve accessibility in different digital contexts.