What's the Difference Between Usability and Accessibility?

Published November 24, 2022

Website usability measures how simple or challenging something is to use. However, usable digital content isn't necessarily accessible.

Here we'll break down the differences between usability and accessibility and how they work together to create the most optimal user experiences.

Understanding usability

Usability helps us understand the ease of use of any digital technology and explicitly measures systems that facilitate modern media, like the internet.

User-friendly digital content includes clear structures, simple navigation, and responsive design. Furthermore, it's essential to understand that usability combines measurable factors instead of one set property.

According to the official U.S. website, these are the factors designers consider when measuring usability:

  • Intuitive design: a nearly effortless understanding of the architecture and navigation of the site
  • Ease of learning: how fast a user who has never seen the user interface before can accomplish basic tasks
  • Efficiency: How fast an experienced user can accomplish tasks
  • Memorability: after visiting the site, if a user can remember enough to use it effectively in future visits
  • Error frequency and severity: how often users make errors while using the system, how serious the errors are, and how users recover from the errors
  • Subjective satisfaction: If the user likes using the system

Once we've identified usability elements, we need to know how to quantify them. Usability evaluations focus on how we can successfully measure those factors.

Evaluating usability

Usability evaluations or tests allow us to measure the quality, effectiveness, and efficiency of a user experience or UX when interacting with digital products or systems.

Several methods measure usability, including wireframe testing, first-click testing, satisfaction surveys, focus groups, interviews, and more.

Usability testing helps us discover problems in the design, find opportunities to improve, and learn about users.

According to American UX consulting firm Neilson Norman Group, most usability testing includes a researcher or facilitator, the individual who instructs a remote or in-person participant through the testing process or tasks.

Tasks are testing points based on facilitator research that a participant is asked to reenact in a controlled setting. Typically, tasks are digital experiences participants utilize daily. For example, one task might be visiting a library website to search for a book a reader plans to check out.

Ways to measure usability

Testing for usability might be qualitative or quantitative. Qualitative testing is the most common, describing participant opinions and observations.

Quantitative testing describes what happens during a test, including metrics that help facilitators determine new testing criteria and re-tests.

Though usability is based on user experiences, it does not inherently include a direct focus on users with disabilities.

That's where accessibility comes in.

Accessibility is a part of usability

Digital accessibility reduces barriers that block users with disabilities from accessing websites, digital tools, and other technology. The World Wide Web Consortium (W3C) describes web accessibility as the ability of persons with disabilities to comprehend, navigate, engage, and contribute to the web.

While usability focuses on a collection of user-friendly characteristics on a digital product or system, digital accessibility helps expand the concept of user-friendly characteristics by directly responding to needs presented by individuals with disabilities.

As a result, accessibility testing is a subset of usability testing in which the test subjects have disabilities that affect how they use the web.

How usability and accessibility overlap

Since the Americans with Disabilities Act (ADA) was passed in 1990, discrimination based on disability has been illegal. Section 508 of the Rehabilitation Act was updated in 1998 to require federal government agencies to make digital technology accessible.

However, due to the ever-changing technological landscape, ADA laws for non-federal digital products and services are more complex.

Even though no specific digital accessibility standard is required by law for many U.S. digital products and systems, there are many reasons websites should be as accessible as possible.

The growing significance of accessibility

Accessible websites and digital products increase brand reach and recognition. Research shows that 62% of consumers like brands willing to take bold stances on issues like digital activism.

Plus, accessible digital systems maximize customer satisfaction.

This is why including people with disabilities in usability testing is so vital. When left out, distinct issues can arise. For example, a user interface that tests well with hearing users may have poor screen reader support or lack features for users who are deaf or hard of hearing.

It's time to start rethinking usability with accessibility in mind so that all users, regardless of disability, can have as much freedom and satisfaction as possible when using the internet.

Event: Accessible Mobile Apps and Kiosks

Join us on Tuesday, August 22nd at 1 PM ET for our next event on Accessible Mobile Apps and Kiosks.  We need to ensure self-service is accessible to everyone.

The self-service trend for customers through mobile apps and kiosks has exploded in recent years. Identify gaps in your processes that may prevent all customers from utilizing these tools. Explore how to provide an accessible user experience for all when designing, developing, and deploying mobile apps and kiosks.

Register for this free, online event here.

Catch Design, Develop and Deploy for Accessibility On Demand

Did you miss our Design, Develop and Deploy for Accessibility series? Not to worry.  It is now available on demand for you to catch on your own time. Grab the videos, transcripts, and supporting materials by clicking this link.


Vendor Directory

Accessibility.com now offers an impartial listing of digital accessibility vendors.  Search for products and services by category, subcategory, or by company name.  Check out our new Vendor Directory here.