What Is Use Case Testing? Understanding Functional AT Testing and its Applications

Functional assistive technology (AT) testing, commonly known as “use case testing,” is a vital part of any comprehensive digital accessibility strategy. In these evaluations, native AT users test high-traffic user flows, such as checkout experiences and registration pages, to ensure they work properly for people with disabilities. It’s more focused and thorough than other types of evaluation, and brings valuable real-world perspective to the auditing process. But what does this testing mean in practice—and when should you prioritize it?

This post explains what functional AT testing is, how it works, and how it fits into the broader scope of an accessibility audit.

What is functional AT testing?

Functional AT testing is real-world, scenario-based testing performed by native users of AT—most commonly, users of screen readers, magnifiers, and voice tools. These testers evaluate the core functions and pathways of a digital product—such as the check-out flow on an e-commerce website or mobile check deposit feature on a banking app—to determine whether those experiences are usable.

By engaging with these core flows, called “use cases,” in the way that a real user would, testers provide qualitative insight on the real-world usability of a digital experience for people with disabilities. For example, can someone who uses a screen reader actually accomplish the tasks they need to, like making a purchase, on your site? And how intuitive or cumbersome is it to do so? Functional AT testing answers these questions by validating the user experience from the perspective of real people with disabilities, including those who rely assistive technology in their daily lives.

How does functional AT testing work?

Functional AT testing (or use case testing) simulates real-world scenarios by having native AT users navigate key tasks and situations they may encounter along the way, such as:

• Logging into an account.
• Making a purchase.
• Filling out forms.
• Navigating error messages.
• Accessing account settings or support options.

Each of these test cases is structured to reflect a common use case for the product or service. During testing, an AT user evaluates and documents whether they can successfully and efficiently complete the task.

For example, a test case for an e-commerce website might involve a native screen reader user adding multiple products to a cart, applying a promo code, and checking out. The tester might flag barriers such as:

• Missing or vague button labels which might prevent the user from knowing which variant of the item they are choosing.
• Unclear feedback on the use of a promo code.
• Checkout flow breakdowns due to modal handling.

In addition to traditional manual audits, which assess conformance with accessibility standards like the Web Content Accessibility Guidelines (WCAG), functional AT testing helps you understand how well the experience actually works for AT users.

Common test cases

To be effective, functional AT testing should be tailored to your product’s unique purpose and audience. That means the use cases you choose to test should reflect the most common goals that your users have when engaging with your digital experiences.

The following table lists some examples of frequently tested user journeys by industry. Each of these is broken into more granular use cases for targeted testing.

Industry	Commonly tested user journeys
Retail/e-commerce	Account creation and login Product search and comparison Add-to-cart and checkout Order tracking
Financial services	Account access and balance inquiries Online bill payments Mobile check deposit Loan application flow
Telecommunications	Browsing and customizing service plans Paying bills Scheduling service appointments
Travel and hospitality	Searching and booking accommodations Comparing prices and packages Applying loyalty points
Education	Student application and registration Accessing online textbooks and libraries Viewing grades and assessments
State and local government	Voter registration Paying fines online Requesting accommodations Viewing council meetings and public records

 

How does functional AT testing complement other types of accessibility testing?

Functional AT testing is an integral part of a comprehensive approach to accessibility testing, which also includes:

• Automated scanning: Automated scanning tools provide rapid insight on the accessibility of digital experiences. They’re especially useful for identifying issues quickly at scale, and for testing code while it’s still in development. However, automated scans only detect many of the most common issues—they can’t catch everything.
• Manual testing: Manual audits performed by accessibility experts are critical to catch issues that automation can’t. During this testing, professionals evaluate core pages, components, and user flows for conformance with established accessibility standards. Many—but not all—manual testers are native AT users. However, this practice is primarily focused on conformance, rather than user experience.

While automated and manual testing empower teams to surface accessibility issues and benchmark compliance, neither approach offers real-world insight on the user experience of people with disabilities. Functional AT testing fills this gap by providing user-centric perspective. While it doesn’t replace automated or manual testing, it completes the picture.

Functional AT testing vs. manual auditing

Because both functional AT testing and manual auditing are performed by human testers using AT, it can be easy to confuse these two types of evaluation. You can use this table to understand some of the key differences:

Feature	Functional AT testing	Manual auditing
Tester background	Native AT user with one or more disabilities	Accessibility expert (who may not may not be a native AT user)
Goal	Evaluate usability for people with disabilities in real-world applications	Assess conformance with technical accessibility standards
Tools used	Including but not limited to: Screen readers, keyboard navigation, screen magnification, speech recognition, keyboard navigation	Including but not limited to: Screen readers, keyboard navigation, browser zoom, mobile accessibility features
Scope	End-to-end user journeys	Core pages, components, and user flows
Output	Functional barriers and user impact	Violations of technical standards, such as WCAG

 

When should you consider functional AT testing?

Functional AT testing is the best way to ensure that any digital experience is not only conformant with technical standards and compliant with accessibility laws, but also usable for everyone. However, engaging a professional to test use cases isn’t as simple as running an automated scan—it can take time and resources. For that reason, most teams choose to be strategic about when they implement this testing approach.

Functional AT testing may be particularly valuable for your organization if you’re in one or more of the following positions:

• Your product is user-facing.
• You’re updating or launching critical workflows.
• You need user-centered evidence for leadership or legal defense.
• You’re in a high-risk sector (e.g., retail, finance, government).

Functional AT testing: Accessibility testing designed around user needs

Digital accessibility is ultimately about providing equitable experiences for all users. By integrating functional AT testing into your broader testing strategy, you can go beyond baseline compliance requirements and deliver inclusive, enjoyable experiences for everyone.

At Level Access, we’ve spent more than 25 years helping organizations worldwide meet their accessibility goals. Our end-to-end solution spans the three pillars of successful accessibility programs: Audit & Test, Build & Fix, and Governance & Reporting.

Whether you’re considering functional AT testing or looking for other ways to boost your accessibility practice, our team is ready to help. Contact Level Access today to learn how we can support your journey toward sustainable accessibility and compliance.

Frequently asked questions (FAQ)

What is use case testing in accessibility testing?

Use case testing in accessibility testing is a method of validating real-world user flows to ensure that functionality behaves as expected. In accessibility, it refers to testing tasks from a user’s point of view, especially with assistive technologies. 

What’s the difference between functional testing and functional AT testing?

Functional testing checks if software performs as intended. Functional AT testing goes further—it evaluates whether that functionality is accessible and usable for people with disabilities using assistive technologies.