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A11y Wars: The Accessibility Interpretation Problem

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Without a shared testing perspective, achieving accurate test results for compliance with WCAG 2.0 can be challenging and expensive. A common cause for inconsistent accessibility results between experts is accessibility testers doing their work with different goals in mind. A natural tension exists between the goals of users, designers, developers, testers, trainers, project managers, and executives.

An unstated goal for testing can be a major source of inconsistent results between tests. It is time to stop the accessibility interpretation wars. There is no “one best way” of interpreting accessibility standards. There are different interpretations, each valid and useful in their own right. The Accessibility Peace Model identifies the following key perspectives used for accessibility testing.

Accessibility Peace Model

A lot of time can be lost arguing over what the “correct” interpretation of WCAG 2.0 is. These range from “least effort, in order to comply with regulations” to “looking for an optimal user experience”. People testing WCAG with these two different perspectives in mind will inevitably reach different conclusions.

The Accessibility Peace Model recognizes that there are different ways of interpreting WCAG 2.0, none of which is perfect in every possible situation. For instance, it is possible to be WCAG 2.0 compliant and skip some heading levels. While heading levels may be skipped, the presentation should be used to determine what heading level might be appropriate. This is fairly nuanced, and much harder to understand than a simple “don’t skip heading levels” rule. So, it makes a lot of sense to proactively test for skipped headings during design and code review, and have a nuanced discussion with the lead accessibility expert and compliance officers when challenging heading structure design situations arise.

WCAG 2.0 certainly wasn’t intended to allow for multiple interpretations. But many people have approached accessibility from very different angles, fitting WCAG 2.0 to their particular needs. This makes it problematic to say that one “interpretation” is more or less correct than another. Different interpretations serve different needs. In other words, these differences exist for a valid reason. An interpretation paired with an ideal perspective can be as equally valid as an interpretation paired with a minimum perspective.

The Accessibility Peace Model recognizes that there are different, equally valid, ways to use WCAG 2.0. To get consistent results, organizations should define with what perspective they want their tests to be done. This is by no means the only measure that needs to be taken to ensure consistency, but it does make discussions on interpretations significantly more effective. 

To help set expectations for results, the Accessibility Peace Model defined three viewpoints along the spectrum of interpretations:

  • Minimum – Content is only non-compliant if this can be proven without any doubt, based exclusively on the normative text of the accessibility guidelines.
  • Optimized – Interpretations are based on the intent of success criteria, gauged by all the information provided by the W3C about the accessibility guidelines.
  • Idealized – Maximise accessibility by requiring that suboptimal user experience solutions be avoided and that best practice techniques always be used as a way to pass success criteria.

Minimum Interpretation

How do you define it?

Minimum Interpretation is based on the normative text of the technical requirement. The starting point for this interpretation is that content is compliant until proven otherwise.  It is very important to understand the differences between normative and informative.  

The following is the definition of “normative” from WCAG 2.0:

  • normative – required for conformance
    • Note 1: One may conform in a variety of well-defined ways to this document.
    • Note 2: Content identified as “informative” or “non-normative” is never required for conformance.
  • informative – for information purposes and not required for conformance.

For WCAG 2.0, only the following texts are normative:

Informative text that can be used for research and understanding, but never for final decision making. Some of the WCAG 2.0 informative texts are:

  • Understanding WCAG 2.0 is informative and should be reviewed to provide context. But interpretation decision must be fully based on WCAG 2.0 normative text.
  • Techniques for WCAG 2.0 are informative and therefore not required. They should be reviewed to provide context.  But interpretation decisions must be fully based on WCAG 2.0 normative text.

When there are two reasonable interpretations, support the narrower interpretation because it is all that is minimally required.

Who uses this?

This interpretation is particularly useful for organizations with urgent accessibility issues to resolve. Legislation may have changed and suddenly many new requirements have to be met. With limited resources and short deadlines, difficult decisions have to be made.

Accessibility remediation is a costly endeavor that can result in tech debt. This interpretation is particularly useful when retrofitting websites that weren’t built with accessibility in mind. Executive leaders, legal counsel, and compliance officers need to know what the absolute minimum requirement is so they can make informed decisions about which problems to solve now and which should be done in the inevitable redesign.

It may seem like the minimum interpretation is one that makes the most business sense, since it focuses on the least number of changes necessary. However, many years of experience shows us that this isn’t the case. This interpretation is particularly poor for teaching accessibility. By focusing on the legal requirements, this mindset ignores that accessibility is about people and good design. Many people (developers and designers included) struggle to do work they don’t see the benefit of. This inevitably leads to cutting corners that are costly to resolve after the fact. Once this initial “bar” is crossed, organizations should transition into using the optimized interpretation, since it is far less costly to maintain long-term accessibility.

Optimized Interpretation

How do you define it?

Optimized Interpretation is based on the spirit and intent of the normative technical requirement, rather than just minimum compliance. Optimized is smart and sustainable universal design. It suggests a pragmatic inclusive design approach that balances equal access, civil rights, and actual outcomes for users with disabilities with what is technically possible and reasonable to achieve today.

The WCAG 2.0 Understanding documents are particularly important in implementing this interpretation. They give guidance to what kinds of accessibility concerns should be addressed in the content. The focus here is on striking a balance between the needs of users as they are described in the understanding documents and the effort to put into these features.

If it takes minimal effort to create something in a way that falls within a user’s needs as described in the understanding document, then the optimal interpretation requires that this is how it must be created, even if it can be argued that the normative part of WCAG does not explicitly require it.

Who uses this?

The optimal interpretation is about creating a balance between the needs of users with disabilities and competing business needs. It is useful in organizations that want to maintain a steady level of accessibility in the long term without breaking the bank.

Teaching the optimal interpretation to developers, designers, and QA testers will help them to be motivated about accessibility. It teaches them there are good business reasons to not cut corners when doing accessibility, but also that there are competing business priorities to meet so that they shouldn’t go overboard and try to create ivory tower accessibility.

Idealized Interpretation

How do you define it?

Idealized interpretation is based on a human factors approach that extends beyond legal compliance and pragmatic best practices. The idealized interpretation focuses on the quality of the user experience for people with disabilities and innovative breakthroughs that eliminate barriers once considered impossible to solve.

This approach prioritizes equal access and civil rights while also striving for delightful usability for people with disabilities. Even when there is no readily available solution or implementation is very expensive, the idealist meets the challenge head-on, refusing to be satisfied with mediocrity.  

An idealized interpretation of digital accessibility would be based on the following:

Who uses this?

Accessibility experts, people with disabilities, savvy designers, and developers know that accessibility can be used as a catalyst for innovation. Just because something is challenging today, does not mean we should not do it.

This focus on a delightful experience for users with disabilities can be useful for organizations that treat accessibility as a high priority. Some organizations use universal design as a competitive advantage, broadening their market reach. Organizations with a social function and organizations trying to set an example will often use the idealized interpretation.

Teaching the idealist interpretation isn’t just about understanding the needs of people with disabilities. Finding the ideal solution often requires an understanding of assistive technologies and user agents. This is a much higher bar to cross, and a costly one at that. Not every developer, designer, or QA tester needs to be an expert on assistive technologies. Organizations using the idealized interpretations will need at least one of these accessibility experts available to every team.


Over the years, a lot of time has been spent arguing back and forth over how to interpret WCAG 2.0. It is clear that there are different approaches to using the standard, useful in different situations. Before doing any design, development or accessibility testing, we recommend looking at the accessibility objective for the product. Knowing your accessibility objective will help you understand what interpretation is most appropriate.

  1. Meet Requirements (Minimum)– Organizations that urgently need to make existing products compliant to WCAG 2.0 are often best off following a minimum interpretation. Fixing the WCAG 2.0 minimum barriers first is an excellent use of limited resources in a very short time frame. Although not a great fit for maintaining accessibility websites in the long run, this interpretation helps decide on what must happen now, and what can wait.
  2. Sustainable Universal Design (Optimized) – For organizations that are starting a new project, or that have a (mostly) accessible website now and are looking to keep it this way, the optimized interpretation is the best fit. It establishes buy-in from designers and developers based on the intrinsic benefits of universal design.  It requires balanced decisions between the needs of users and those of the business.
  3. Boldly Go Where No One Has Gone Before (Idealized) – When trying to push the boundaries of what’s technically possible today, organizations often use the idealized interpretation. Striving for an ideal approach may be difficult to balance with business needs, but can create exceptional long-term value. Amazing accessibility advancements occur when research and development improve reusable components and pattern libraries. However, it could take a great deal of time, money, resources, testing, and expertise with assistive technology to consistently work at this level.

The chosen interpretation should be established and communicated in the project definition and reinforced in advance of any design, development, and testing. Testers must confirm which interpretation to use, to ensure they’re not spinning developers in circles. For example, a project using the minimum interpretation expects issues to only be reported for WCAG normative violations. But a tester using an optimized interpretation would also report best practice violations. Developers become frustrated because new issues come up in content they already thought was accessible.

Best Practices and Accessibility Optimization

In the struggle of who has the “right” interpretation of WCAG 2.0, there really aren’t any winners. Furthermore, the people losing out are those who could have benefitted from that time spent in more productive ways. By acknowledging that these perspective exist, we hope to end pointless discussions and gain an understanding of where these differences come from. To truly get away from an unproductive discussion, we will need to find common ground.

It seems unlikely to the authors that the end of the A11Y Interpretation War can be achieved with a single white paper. We believe that future accessibility standards can help address this problem by using the Accessibility Peace Model. There is certainly no silver bullet solution here, but one way may be promising is by working with best practices and optimization suggestions:

  1. Best Practice: A rule that should always be applied by designers and developers to new products which will certainly improve its accessibility, but which may or may not be a violation of WCAG 2.0, depending on the context.
  2. Optimization: A technique that has the widest possible support, and will work for the most amount of users, irrespective of the accessibility support baseline that was set to meet the WCAG 2.0 conformance requirements.


By clearly defining the perspective your organization is using for accessibility testing, your organization can cut down on the interpretation differences, clearly define accessibility goals, and stop inconsistent accessibility testing, making accessibility testing more efficient which in turn saving time and lowering costs. 
To read the full White Paper “A11Y Wars: The Accessibility Interpretation Problem” by Wilco Fiers and Glenda Sims.
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About Glenda Sims

Glenda Sims is the Chief Information Accessibility Officer at Deque, where she shares her expertise and passion for the open web with government organizations, educational institutions, and companies ranging in size from small businesses to large enterprise organizations. Glenda is an advisor and co-founder of AIR-University (Accessibility Internet Rally) and AccessU. She serves as an accessibility consultant, judge, and trainer for Knowbility, an organization whose mission is to support the independence of people with disabilities by promoting the availability of barrier-free IT. In 2010 Glenda co-authored the book InterACT with Web Standards: A holistic approach to Web Design.
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