What is usability?

How usable is your product?

I have a love-hate relationship with some digital products, and it’s because of their usability. Well, mostly hate in some cases. And not because I don’t love the idea. But using the software is frustrating and drives me crazy.

Jira screen showing how to create a taskTake Jira, for example, a cloud-based project management software from Atlassian. We use it to manage our projects. I like things about it: I like the reports and how I can track projects over time. I like all of the templates I can use to set up projects. And I like how flexible it is, so I can customize the screens for our company workflow.

But there are things about Jira that really frustrate me. I don’t like how I can never remember how to move a task I created in one project over to another. Or that somehow I have two active sprints going, and I can’t figure out for the life of me where one of them is so I can stop it.

And that’s where usability comes in.

What does usability mean?

When we talk about usability, I prefer this definition from Jeff Rubin and Dana Chisnell in the Handbook of Usability Testing:

When a product or service is truly usable, the user can do what he or she wants to do the way he or she expects to be able to do it, without hindrance, hesitation, or questions.

Usability — at its most basic — means how easy a product or service is to use. It’s a core part of the overall user experience.

And within usability, there are multiple factors to consider. Nielsen Norman Group defines usability by five components:

  1. Learnability
    Are users able to figure out and accomplish a task the first time they encounter a design
  2. Memorability
    Are users able to remember how to accomplish a task when they return to a design after a defined amount of time?
  3. Errors
    Are users making errors? How many errors, and how severe?
  4. Satisfaction
    Do users find a design pleasing to use?
  5. Efficiency
    Once users learn how to do something, how quickly are they able to accomplish a task?

Rubin and Chisnell add three more important elements to what makes a design usable:

  • Useful
    Is a user willing to use the design at all?
  • Effective
    Does the design behave the way users expect it to, and can they use it as easily?
  • Accessible
    Is the user able to access the design?

Clearly, usability is more than just determining whether something is “user-friendly.” This is an outdated term that should probably be put out of its misery. What’s more, we need to take context into account. How are users accessing our design? Under what circumstances are they operating mentally, emotionally, and situationally in order to accomplish a task?

Person using access window to log in or to create new web account. Enter login and password. Cyber protection. Information privacy. Internet and technology concept. Screen close up back view

Let’s go back to my Jira example. I complained about the usability of certain features in the tool, but I’ll bet dollars to donuts that the UX team at Atlassian has tested the application for usability. They’re smart people, so I’m sure they tested. But how many tests? And how many people? Or maybe the testing was rigorous, but they just didn’t test a situation that was close to what I was experiencing. Maybe my issues are triggered by a different situation or emotional context than they anticipated.

There’s a lot that goes into usability. And just because I struggle with the usability of a product doesn’t mean everyone will or that it wasn’t tested at all.

Why is usability important?

Usability is a sub-discipline of user experience. UX and usability were once terms that were used interchangeably, but not anymore. User experience is a broad subject with many different factors.

But usability is still extremely important. After all, if our designs are not efficient, learnable, effective, accessible, memorable, or even satisfying, people are unlikely to use them.

Think about the implications of usability and how it affects a product or service.

Anyone up for pizza?

Woman ordering pizza online

Let’s say I have a pizzeria, and I have a website where customers can order online. How does usability affect my bottom line?

If my customers don’t find my website as usable as the pizza delivery competitor down the street, then they may take their business down the street as well.

How much money could I be losing because my website isn’t as usable as the other guy’s website?

That’s why usability is important.

How do we find out if a design is usable?

Usability testing can take place in many forms. So let’s start with what it is not.

Sometimes usability testing is confused with quality assurance (QA) testing. They are both necessary, but they are not the same.

Usability testing and QA testing both have different focuses. Usability testing seeks to understand how usable a design is based on the guidelines above. QA testing looks for bugs or flaws in the functionality of an application. An application with bugs could still be usable, and vice versa.

Early and often

Usability testing can be done multiple times throughout the design process and even into development. Steve Krug, author of Don’t Make Me Think, says it’s better to do small tests throughout than to wait until the end to do one big usability test. Testing early and often can uncover problems when they are less expensive to fix.

The form usability testing takes can vary depending on how fleshed out a design is.

In early stages, a usability test could be as simple as having a colleague walk through a series of sketches like an end user would. Your colleague can identify gaps in the design that could cause it to be unusable. Is it the perfect test? No, of course not. But it’s getting another set of eyes on your design.

Later, testing usually starts with a plan that guides who to test and exactly what will be tested. The plan explains how and who to recruit, how the test should be conducted, and how the testing data will be used.

It’s ideal to test designs on people who aren’t familiar with what you’re doing. That way you can gain valuable feedback that helps make the product usable for everyone.

What are we looking for when we test usability?

Pizza website usability

If we go back to my fictional pizzeria website, let’s say I’ve heard my website isn’t as good as my competitor’s, and I’m ready to fix it. What do we do first?

Let’s find out how the website does against the key components of usability. We’ll plan a usability test on people who roughly meet the demographic profile of my customers. In that test we’ll have the participants try to complete a series of tasks.

  • Is the site learnable?
    Are participants able to order a pizza without ever having seen the site before? Can they quickly learn how to use the interface without questions?
  • Is the site efficient?
    Once a participant figures out how to order a pizza, how quickly can they do it?
  • Is the site effective?
    Does the site behave the way participants expect? If they click the “order now” button, does it take them where they expect to go?
  • Is the site memorable?
    If the users leave and come back, can they remember how to order a pizza or check on their order?
  • Are users making errors?
    When participants order a pizza, are they making mistakes? Do the errors cause enough frustration for them to give up and abandon the order?
  • Is the site satisfying?
    Do participants enjoy using the site? Do they mention that the site looks nice or do they say it looks “old?”
  • Is the site useful?
    Do participants even want to use the site to order a pizza at all, or does it make them want to call?
  • Is the site accessible?
    Is the participant able to access the site to order a pizza if they have a disability?


This first step to success is being curious about usability. When you genuinely lean into thinking about how usable your designs will be for people, you have a much better chance of a positive outcome.

Usability isn’t synonymous with user experience, but it is a key component.

When you understand that usability is more than “user-friendly” and that there are many components that make a product or application usable, you’re already helping to improve the experience for people.

Usability Resources

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